React is a JavaScript library for building user interfaces that was developed by Facebook. It is designed to make it easy for developers to create interactive, high-performance applications that are able to efficiently update and render large amounts of data. React is based on the concept of “components,” which are self-contained units of code that represent a piece of the user interface. Components can be composed to create more complex UI elements, and they can be easily reused across an application.
React also includes a virtual DOM (Document Object Model) that allows it to efficiently update the UI when the underlying data changes. It does this by minimizing the number of DOM manipulation operations that are required, which can improve the performance of the application. React is widely used in web development and has a large and active community of developers. It is often used to build single-page applications (SPAs), mobile applications, and other complex UI-based projects.

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The following issues are the most popular issues regarding this project:

ERROR Invariant Violation: Module AppRegistry is not a registered callable module ( React native V6)

This error typically indicates that there is a problem with the configuration of the React Native application, or with the way that it is being launched.

There could be a few different causes for this error:

1. The application might not be properly registered with the AppRegistry module. In a React Native application, the AppRegistry module is responsible for managing the lifecycle of the application and for starting the main component of the app. If the app is not properly registered with the AppRegistry, it will not be able to start and this error will occur. To fix this issue, you might need to check that the app is correctly registered with the AppRegistry in the index.js or App.js file of the project.
2. There might be a problem with the dependencies or configuration of the React Native project. In this case, you might need to check that you have all of the necessary dependencies installed and that they are correctly configured. You might also need to check that the react-native and react packages are correctly installed and that there are no conflicts between different versions of these packages.
3. There might be an issue with the development environment or with the device or emulator on which the app is being run. In this case, you might need to check that you have the necessary tools and libraries installed and configured correctly, and that there are no issues with the device or emulator. You might also need to check the logs of the device or emulator to see if there are any other error messages that could help to identify the issue.

npx react-native run-android not working

npx react-native run-android is a command that is used to build and run a React Native app on an Android emulator or device. If it’s not working for you, there could be a few different issues that might be causing the problem. Here are a few things you can try:

1. Make sure that you have an Android emulator or device connected to your development machine.
2. Make sure that you have the latest version of the React Native command line tools installed. You can update them by running npm install -g react-native-cli.
3. If you’re using an emulator, make sure that it is running and that you have specified the correct target AVD (Android Virtual Device) in the run-android command. You can do this by adding the --avd flag followed by the name of your AVD.
4. Check the output of the command for any error messages or logs that might provide clues as to what is causing the problem.
5. Make sure that you have a correct and up-to-date version of the Android SDK (Software Development Kit) installed on your development machine.

onChange doesn’t fire if input re-renders due to a setState() in a non-React capture phase listener

It’s expected behavior for the onChange event not to fire if the value of an input element is changed programmatically, as the onChange event is only triggered by user interaction. If you want to execute some code when the value of an input element changes, you can use the ref system to get a reference to the element and attach a change event listener to it. Here’s an example:

class MyComponent extends React.Component {
  inputRef = React.createRef();

  componentDidMount() {
    this.inputRef.current.addEventListener('change', this.handleChange);
  }

  componentWillUnmount() {
    this.inputRef.current.removeEventListener('change', this.handleChange);
  }

  handleChange = () => {
    // Do something when the input value changes
  }

  render() {
    return <input ref={this.inputRef} />
  }
}

Alternatively, you can use the defaultValue prop to set the initial value of the input element and the onChange prop to specify a handler function that will be called whenever the value of the input element changes due to user interaction.

class MyComponent extends React.Component {
  handleChange = (event) => {
    // Do something with the event.target.value
  }

  render() {
    return <input defaultValue="initial value" onChange={this.handleChange} />
  }
}

“NotFoundError: Failed to execute ‘removeChild’ on ‘Node'” when using React.Fragment <></> with Chrome extension which does not modify the DOM tree below the root div of the React app

The error “Failed to execute ‘removeChild’ on ‘Node'” usually occurs when you try to remove a node from the DOM that has already been removed, or when you try to remove a node that is not a child of the element you are trying to remove it from.

In the case of a React app, this error can occur if you are using a Chrome extension that modifies the DOM tree outside of the root div of your app, and this extension causes the structure of the DOM tree to change in a way that causes React to try to remove a node that no longer exists or that is no longer a child of the element it was originally added to.

To fix this problem, you can try the following:

1. Make sure that your Chrome extension is not modifying the DOM tree below the root div of your React app.
2. If your extension needs to modify the DOM tree below the root div of your app, you can try wrapping the root div in a React.Fragment element, which will prevent React from trying to remove the nodes that are being modified by the extension.

Here’s an example of how you can use a React.Fragment element to wrap the root div of your app:

ReactDOM.render(
  <React.Fragment>
    <div id="root">
      {/* Your app goes here */}
    </div>
  </React.Fragment>,
  document.getElementById('root')
);

React Native App Crashes on Launch in Android (API 19)

There could be a few different reasons why your React Native app is crashing on launch in Android API 19. Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have correctly set up your development environment for React Native, including installing the necessary dependencies and tools such as the Android SDK and an Android emulator or device.
2. Check the logcat output for any error messages or stack traces that might provide clues as to what is causing the crash. You can view the logcat output by running adb logcat in a terminal window.
3. Make sure that you have correctly configured the android field in your app’s package.json file. This field should contain the name of the main Android activity for your app.
4. Try running the app on a different Android emulator or device, or try using a different version of the Android API to see if the problem persists.
5. Make sure that you have the latest version of the React Native command line tools installed. You can update them by running npm install -g react-native-cli.

Command PhaseScriptExecution failed with a nonzero exit code

The error “Command PhaseScriptExecution failed with a nonzero exit code” usually occurs when there is a problem with one of the scripts defined in your Xcode project’s “Build Phases” tab. It can be caused by a variety of issues, such as a syntax error in a script, a missing dependency, or a conflict between different libraries or frameworks.

To troubleshoot this issue, you can try the following steps:

1. Check the Xcode output console for any error messages or stack traces that might provide clues as to what is causing the problem.
2. Make sure that you have correctly configured all of the scripts in your project’s “Build Phases” tab and that they are able to run without errors.
3. Check your project’s dependencies and make sure that all of the required libraries and frameworks are correctly installed and linked.
4. If you are using Cocoapods to manage your project’s dependencies, try running pod install and then clean and rebuild your project.
5. If you have recently made changes to your project’s dependencies or build configuration, try reverting those changes and see if that fixes the problem.

[Android] Images are not showing using local assets or remote image

If images are not showing in your React Native app on Android, there could be a few different issues that might be causing the problem. Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have correctly referenced the image file in your code. If you are using a local image file, make sure that the file is located in the correct directory and that the path to the file is correct. If you are using a remote image, make sure that the URL to the image is correct and that the image is accessible.
2. Check the logcat output for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you have correctly configured your app’s build settings to allow for the inclusion of local or remote images. In your app’s build.gradle file, make sure that the res directory is included in the sourceSets block.
4. Try using a different image file or URL to see if the problem persists.
5. If you are using a local image file, try using a remote image to see if the problem is specific to local images.

Error: Failed to load plugin ‘prettier’ declared in ‘.eslintrc.js » @react-native-community/eslint-config’: Cannot find module ‘eslint-plugin-prettier’ Require stack

The error “Failed to load plugin ‘prettier’ declared in ‘.eslintrc.js’…” usually occurs when you are using the eslint-config-react-native-community package in your project and the eslint-plugin-prettier plugin is not installed or is not correctly configured in your project.

To fix this error, you can try the following steps:

1. Make sure that you have the eslint-plugin-prettier package installed in your project. You can install it by running npm install --save-dev eslint-plugin-prettier or yarn add -D eslint-plugin-prettier.
2. In your project’s .eslintrc.js file, make sure that the prettier plugin is correctly configured in the plugins array and that the prettier/prettier rule is correctly configured in the rules object.

Here’s an example of how your .eslintrc.js file should look if you are using the eslint-config-react-native-community package and the eslint-plugin-prettier plugin:

module.exports = {
  extends: ['@react-native-community'],
  plugins: ['prettier'],
  rules: {
    'prettier/prettier': 'error',
  },
};

[iOS] Failed building app with Hermes enabled

If you are getting an error when building a React Native app for iOS with Hermes enabled, there could be a few different issues that might be causing the problem. Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have correctly configured your project to use Hermes by following the steps in the React Native documentation. This includes installing the hermes-engine package and adding the hermes_path field to your app’s ios/Podfile file.
2. Check the Xcode output console for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you are using a compatible version of the hermes-engine package and that it is correctly installed in your project.
4. If you are using Cocoapods to manage your project’s dependencies, try running pod install and then clean and rebuild your project.
5. Try disabling Hermes and see if the problem persists. If the problem goes away when Hermes is disabled, it could be an issue with your Hermes configuration or with a conflict between Hermes and another library or framework in your project.

React native deep linking not working when app is in background state

Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have correctly configured your app to handle deep links by following the steps in the React Native documentation. This includes setting up the LSApplicationQueriesSchemes array in your app’s Info.plist file and implementing the Linking module in your app’s JavaScript code.
2. Check the logcat output (for Android) or the Xcode output console (for iOS) for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you are using a compatible version of the react-native-linking library and that it is correctly installed in your project.
4. If you are using a custom URL scheme for your deep links, make sure that the scheme is correctly registered in your app’s Info.plist file (for iOS) or in your app’s AndroidManifest.xml file (for Android).
5. Try testing your deep links in the foreground state of your app to see if the problem persists. If the problem only occurs when the app is in the background state, it could be an issue with how your app is handling the app state transition.

Apple M1: Folly errors “can’t modify frozen String (FrozenError)”

If you are getting “can’t modify frozen String” errors when running a React Native app on an Apple M1 device, it could be an issue with the folly library, which is used by React Native to implement certain low-level features.

To fix this issue, you can try the following steps:

1. Make sure that you have the latest version of the folly library installed in your project. You can update the library by running npm install --save folly or yarn add folly.
2. If you are using Cocoapods to manage your project’s dependencies, try running pod install and then clean and rebuild your project.
3. Check the Xcode output console for any error messages or stack traces that might provide clues as to what is causing the problem.
4. If you are using third-party libraries or plugins that depend on folly, make sure that they are compatible with the version of folly that you are using.
5. If you are using the hermes JavaScript engine, try disabling it and see if the problem persists. The hermes engine has been known to cause issues with the folly library on Apple M1 devices.

[ANDROID] SoLoader error using App Bundle

The SoLoader error is often related to issues with native libraries in a React Native app. If you are getting this error when using an App Bundle on Android, it could be caused by a few different issues:

1. Make sure that you have correctly configured your project to use an App Bundle by following the steps in the React Native documentation. This includes setting up the bundleInDebug and bundleInRelease fields in your app’s build.gradle file.
2. Check the logcat output for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you have correctly linked all of the native libraries that your app depends on. You can check the status of your native libraries by running react-native link.
4. If you are using Cocoapods to manage your project’s dependencies, try running pod install and then clean and rebuild your project.
5. If you have recently made changes to your project’s native dependencies or build configuration, try reverting those changes and see if that fixes the problem.

xcode 11.4 build fatal error: module map file xxx/Build/Products/Debug-iphoneos/YogaKit/YogaKit.modulemap’ not found

The error “fatal error: module map file xxx/Build/Products/Debug-iphoneos/YogaKit/YogaKit.modulemap’ not found” usually occurs when there is a problem with the YogaKit library in a React Native app for iOS. This error can be caused by a few different issues:

1. Make sure that you have correctly installed and linked the yogakit-library package in your project. You can do this by running npm install --save yogakit-library or yarn add yogakit-library, and then running react-native link yogakit-library.
2. Check the Xcode output console for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you are using a compatible version of the yogakit-library package and that it is correctly installed in your project.
4. If you are using Cocoapods to manage your project’s dependencies, try running pod install and then clean and rebuild your project.
5. If you have recently made changes to your project’s dependencies or build configuration, try reverting those changes and see if that fixes the problem.

Metro bundler not starting when running run-android / run-ios command on linux

If the Metro bundler is not starting when you run the react-native run-android or react-native run-ios command on Linux, there could be a few different issues that might be causing the problem. Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have correctly set up your development environment for React Native, including installing the necessary dependencies and tools such as the Android SDK (for react-native run-android) or Xcode (for react-native run-ios).
2. Check the terminal output for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you are using a compatible version of the react-native-cli package and that it is correctly installed in your project. You can update the package by running npm install -g react-native-cli or yarn global add react-native-cli.
4. If you are using a virtual device or emulator to run your app, make sure that it is correctly configured and that it is running.
5. If you have recently made changes to your project’s dependencies or build configuration, try reverting those changes and see if that fixes the problem.

Unable to resolve locally installed module

The error “Unable to resolve locally installed module” usually occurs when you are trying to import a module that is not correctly installed or configured in your project. There could be a few different issues that might be causing the problem:

1. Make sure that you have correctly installed the module you are trying to import. If you are installing the module locally (e.g. with npm install or yarn add), make sure that you are running the installation command from the root directory of your project.
2. Make sure that you have correctly referenced the module in your code. If you are using a relative file path to import the module, make sure that the path is correct and that the file exists.
3. If you are using a third-party library or plugin that depends on other modules, make sure that those dependencies are correctly installed and configured in your project.
4. If you are using a package manager like npm or yarn, try running npm install or yarn install to install all of the dependencies for your project.
5. If you have recently made changes to your project’s dependencies or file structure, try reverting those changes and see if that fixes the problem.

Fatal signal 11 (SIGSEGV), code 2 (SEGV_ACCERR)

The error “Fatal signal 11 (SIGSEGV), code 2 (SEGV_ACCERR)” usually indicates that there is a problem with the native code in a React Native app. This error can be caused by a variety of issues, such as a null pointer dereference, invalid memory access, or a conflict between different libraries or frameworks.

To troubleshoot this issue, you can try the following steps:

1. Check the logcat output (for Android) or the Xcode output console (for iOS) for any error messages or stack traces that might provide clues as to what is causing the problem.
2. Make sure that you have correctly linked all of the native libraries that your app depends on. You can check the status of your native libraries by running react-native link.
3. If you are using a third-party library or plugin that includes native code, make sure that it is compatible with your project and that it is correctly installed and configured.
4. If you have recently made changes to your project’s native dependencies or build configuration, try reverting those changes and see if that fixes the problem.
5. Try running your app in a different emulator or device to see if the problem persists.

event.preventDefault in click handler does not prevent onChange from being called

If calling event.preventDefault() in a click handler does not prevent the onChange event from being called, it could be because the onChange event is being triggered by a different element or action.

To troubleshoot this issue, you can try the following steps:

1. Make sure that you are correctly binding the event.preventDefault() function to the click event of the element you want to prevent from changing. You can do this by passing the event object as an argument to the click handler function, and then calling preventDefault() on the event object inside the handler.

<button onClick={event => {event.preventDefault(); ...}}>Click me</button>

2. Check the HTML structure of your page to make sure that there are no other elements or actions that might be causing the onChange event to be triggered. For example, if you have an input field inside a form element, the onChange event for the input field might be triggered by the form’s submit button.
3. Make sure that you are correctly handling the onChange event for the element you want to prevent from changing. You can do this by passing a function as the onChange prop for the element, and then using the event object to access the element’s value and prevent the default action.

<input onChange={event => {event.preventDefault(); ...}} />

Unable to resolve module `@babel/runtime/helpers/interopRequireDefault` – without changing anything

The error “Unable to resolve module @babel/runtime/helpers/interopRequireDefault” usually occurs when you are trying to import a module that is not correctly installed or configured in your project. This error can be caused by a few different issues:

1. Make sure that you have correctly installed the @babel/runtime package in your project. You can do this by running npm install @babel/runtime or yarn add @babel/runtime.
2. Make sure that you have correctly referenced the module in your code. If you are using a relative file path to import the module, make sure that the path is correct and that the file exists.
3. If you are using a third-party library or plugin that depends on the @babel/runtime package, make sure that the package is correctly installed and configured in your project.
4. If you are using a package manager like npm or yarn, try running npm install or yarn install to install all of the dependencies for your project.
5. If you have recently made changes to your project’s dependencies or file structure, try reverting those changes and see if that fixes the problem.

Deep linking is not working when app is closed/killed

If deep linking is not working in your React Native app when the app is closed or killed, there could be a few different issues that might be causing the problem. Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have correctly configured your app to handle deep links by following the steps in the React Native documentation. This includes setting up the LSApplicationQueriesSchemes array in your app’s Info.plist file and implementing the Linking module in your app’s JavaScript code.
2. Check the logcat output (for Android) or the Xcode output console (for iOS) for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you are using a compatible version of the react-native-linking library and that it is correctly installed in your project.
4. If you are using a custom URL scheme for your deep links, make sure that the scheme is correctly registered in your app’s Info.plist file (for iOS) or in your app’s AndroidManifest.xml file (for Android).
5. On Android, make sure that your app’s intent-filter in the AndroidManifest.xml file is correctly configured to handle deep links. This includes setting the data and category elements for your deep link intent filter.

Only release build of Android crash with React Native version mismatch error

If you are getting a React Native version mismatch error when running a release build of your Android app, it could be because the version of React Native that is bundled with your app is different from the version of React Native that your app is built against. This can cause conflicts between the two versions, which can result in errors or crashes.

To fix this issue, you can try the following steps:

1. Make sure that you are using a compatible version of React Native for your app. You can check the required version of React Native in the package.json file of your project.
2. Check the logcat output for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you have correctly bundled the React Native library with your app. You can do this by running the react-native bundle command and specifying the correct output file and options.
4. If you are using a third-party library or plugin that includes a different version of React Native, try updating or removing the library to see if that fixes the problem.
5. If you have recently made changes to your project’s dependencies or build configuration, try reverting those changes and see if that fixes the problem.

Invariant Violation: Failed to call into JavaScript module method AppRegistry.runApplication(). When Upgrading To React Native v0.70

The error “Invariant Violation: Failed to call into JavaScript module method AppRegistry.runApplication()” usually occurs when there is a problem with the JavaScript code in a React Native app. This error can be caused by a few different issues:

1. Make sure that you have correctly upgraded to React Native v0.70 and that all of your app’s dependencies are compatible with the new version.
2. Check the logcat output (for Android) or the Xcode output console (for iOS) for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you have correctly registered your app’s main component with the AppRegistry module. You can do this by calling the AppRegistry.registerComponent function in your app’s JavaScript code and passing in the name of your main component.
4. If you are using third-party libraries or plugins that include custom native modules, make sure that they are compatible with React Native v0.70 and that they are correctly installed and configured in your project.
5. If you have recently made changes to your project’s dependencies or code, try reverting those changes and see if that fixes the problem.

Fresh react-native (0.66) app does not build on XCode 13, iOS 11.6: compiler error on SysUio.o

The error “compiler error on SysUio.o” when building a fresh React Native app on XCode 13 and iOS 11.6 can be caused by a few different issues:

1. Make sure that you are using a compatible version of React Native and XCode. React Native v0.66 may not be compatible with XCode 13 or iOS 11.6.
2. Check the Xcode output console for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you have correctly set up your development environment for React Native, including installing the necessary dependencies and tools such as the iOS SDK.
4. If you are using third-party libraries or plugins that include custom native modules, make sure that they are compatible with your version of React Native and XCode and that they are correctly installed and configured in your project.
5. If you have recently made changes to your project’s dependencies or build configuration, try reverting those changes and see if that fixes the problem.

Local images are not visible

Here are a few things you can try to troubleshoot the issue:

1. Make sure that the path to your image file is correct and that the file exists at the specified location. You can check the path by logging it to the console or using a tool like adb logcat (for Android) or the Xcode output console (for iOS).
2. Make sure that you have correctly referenced the image file in your code. If you are using a relative file path to import the image, make sure that the path is correct and that the file exists.
3. If you are using a package manager like npm or yarn, try running npm install or yarn install to install all of the dependencies for your project.
4. If you are using a third-party library or plugin that includes images, make sure that it is correctly installed and configured in your project.
5. If you have recently made changes to your project’s dependencies or file structure, try reverting those changes and see if that fixes the problem.

Image component does not load image from specific URI on iOS

If the Image component in a React Native app is not loading an image from a specific URI on iOS, there could be a few different issues that might be causing the problem. Here are a few things you can try to troubleshoot the issue:

1. Make sure that the URI for the image is correct and that the image is accessible at that location. You can check the URI by logging it to the console or by accessing the image in a web browser.
2. Check the Xcode output console for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you have correctly referenced the image URI in your code. If you are using a relative file path to import the image, make sure that the path is correct and that the file exists.
4. If you are using a third-party library or plugin that includes images, make sure that it is correctly installed and configured in your project.
5. If you have recently made changes to your project’s dependencies or file structure, try reverting those changes and see if that fixes the problem.

Warn when calling dispatch() from useEffect() cleanup function on unmounting

It is generally not recommended to call the dispatch function from a useEffect cleanup function on unmounting, as it can lead to unexpected behavior and potential memory leaks. This is because the dispatch function is typically used to update the state of a Redux store, and calling it after the component has unmounted can result in stale or inconsistent data in the store.

To avoid this issue, you can try the following steps:

1. Make sure that you are correctly handling the unmounting of your component. You can do this by returning a cleanup function from your useEffect hook that cancels any pending actions or subscriptions, or by using the useEffect hook with the [] dependency array to run the effect only once.

useEffect(() => {
  const subscription = someObservable.subscribe(dispatch);
  return () => {
    subscription.unsubscribe();
  };
}, []);

2. If you need to dispatch an action when your component unmounts, consider using the useReducer hook instead of the useEffect hook. The useReducer hook allows you to define a reducer function that handles updates to the component’s state, and you can dispatch actions to the reducer from anywhere in your component code.

const [state, dispatch] = useReducer(reducer, initialState);

Bug: radio and checkbox controlled checked property is not updated when browser restores form state

If the checked property of a radio or checkbox input element is not being updated when the browser restores the form state, it could be because the component is being controlled by a parent component, but the parent component is not correctly handling the update of the checked property.

To fix this issue, you can try the following steps:

1. Make sure that the parent component is correctly passing the checked prop to the input element. The checked prop should be set to the value of the checked state in the parent component.

<input type="checkbox" checked={checked} onChange={handleChange} />

2. Make sure that the parent component is correctly updating the checked state when the input element’s onChange event is fired. You can do this by passing a function to the onChange prop of the input element and using the event object to access the new value of the checked property.

const handleChange = event => {
  setChecked(event.target.checked);
};

3. If you are using a form element to wrap the input element, make sure that the form element is correctly handling the update of the checked state. You can do this by adding a name attribute to the input element and using the FormData API to access the values of the form elements when the form is submitted.

const handleSubmit = event => {
  event.preventDefault();
  const formData = new FormData(event.target);
  console.log(formData.get("checkbox"));
};

[TypeError: Network request failed] either with fetch API or axios on android

The error “TypeError: Network request failed” when making a network request using the fetch API or axios in a React Native app on Android can be caused by a few different issues:

1. Make sure that the URL for the network request is correct and that the server is reachable at that location. You can check the URL by accessing it in a web browser or by logging it to the console.
2. Check the logcat output for any error messages or stack traces that might provide clues as to what is causing the problem.
3. Make sure that you have correctly configured the fetch API or axios in your code. If you are using the fetch API, make sure that you are handling the Response object correctly and that you are handling any potential errors that might occur.
4. If you are using a third-party library or plugin that makes network requests, make sure that it is correctly installed and configured in your project.
5. If you have recently made changes to your project’s dependencies or network configuration, try reverting those changes and see if that fixes the problem.

Gradle “Implicit dependencies between tasks” warning on fresh install

The warning “Implicit dependencies between tasks” in Gradle can occur when there are multiple tasks in your build script that depend on the same input file or output file, but the dependencies are not explicitly defined in the build script. This can lead to unpredictable build behavior and can cause issues with task execution order and task up-to-date checks.

To fix this warning, you can try the following steps:

1. Make sure that you have correctly configured your tasks in your build script and that you have defined all of the necessary dependencies between tasks. You can do this by using the dependsOn property to specify the tasks that a particular task depends on.

task taskA {
  doLast {
    // task A code
  }
}

task taskB {
  dependsOn taskA
  doLast {
    // task B code
  }
}

2. If you are using the JavaExec task or the JavaForkOptions.javaExecutable property in your build script, make sure that you are specifying the correct path to the java executable.
3. If you are using third-party libraries or plugins that include custom tasks in your build script, make sure that they are correctly installed and configured in your project.
4. If you have recently made changes to your project’s dependencies or build configuration, try reverting those changes and see if that fixes the problem.

fetch SyntaxError: Unexpected token in JSON at position 0

The error “SyntaxError: Unexpected token in JSON at position 0” when using the fetch API in a React Native app can occur when the server returns a response with an invalid JSON payload. This can happen if the server is returning an HTML page or an error message instead of a valid JSON object.

To fix this issue, you can try the following steps:

1. Make sure that the server is correctly configured to return a valid JSON object in the response. You can check the server’s response by logging it to the console or by using a tool like the Network tab in the browser dev tools.
2. If the server is returning a JSON object, make sure that the object is valid and that it does not contain any syntax errors. You can use a tool like JSONLint to validate the JSON object.
3. If the server is returning an HTML page or an error message, make sure that you are correctly handling the response in your code. You can do this by checking the status property of the Response object and handling any non-200 status codes appropriately.

fetch(url)
  .then(response => {
    if (response.status !== 200) {
      throw new Error(response.statusText);
    }
    return response.json();
  })
  .then(data => {
    // handle data
  })
  .catch(error => {
    // handle error
  });

4. If you are using a third-party library or plugin that makes network requests, make sure that it is correctly configured and that it is handling the response from the server correctly.

iOS Build Error with react-native version – 0.64.0

If you are experiencing an iOS build error with React Native v0.64.0, there could be a few different issues that might be causing the problem. Here are a few things you can try to troubleshoot the issue:

1. Check the Xcode output console for any error messages or stack traces that might provide clues as to what is causing the problem.
2. Make sure that you are using a compatible version of React Native and Xcode. React Native v0.64.0 may not be compatible with newer versions of Xcode.
3. If you are using third-party libraries or plugins that include custom native modules, make sure that they are compatible with React Native v0.64.0 and that they are correctly installed and configured in your project.
4. If you have recently made changes to your project’s dependencies or build configuration, try reverting those changes and see if that fixes the problem.
5. If you are using CocoaPods to manage your project’s dependencies, make sure that you have correctly configured your project’s Podfile and that you have run the pod install command to install the necessary dependencies.

useReducer’s dispatch should return a promise which resolves once its action has been delivered

It is not currently possible to return a promise from the dispatch function of the useReducer hook in React that resolves once the action has been delivered. The dispatch function simply dispatches an action to the reducer function and does not return a value or a promise.

If you need to wait for an action to be delivered before performing some other action, you can use the useEffect hook to listen for changes to the state and perform the desired action when the state is updated.

const [state, dispatch] = useReducer(reducer, initialState);

useEffect(() => {
  if (state.someProperty) {
    // perform action
  }
}, [state]);

Alternatively, you can use the then method of the returned value of the dispatch function to perform an action after the action has been delivered.

dispatch(someAction()).then(() => {
  // perform action
});

import React, { useState } from 'react';
import { Image } from 'react-native';

const MyImage = () => {
  const [source, setSource] = useState(null);

  return (
    <Image
      source={source}
      onLoad={() => setSource({ uri: 'file:///path/to/image.jpg' })}
    />
  );
};

Alternatively, you can use a placeholder image as the initial source of the <Image> component, and then update the source with the local file URI when the image file has finished loading.

import React, { useState } from 'react';
import { Image } from 'react-native';

const MyImage = () => {
  const [source, setSource] = useState({ uri: 'placeholder.jpg' });

  return (
    <Image
      source={source}
      onLoad={() => setSource({ uri: 'file:///path/to/image.jpg' })}
    />
  );
};

nestedScrollEnabled prop not working in ScrollView (Android) with horizontal direction

The nestedScrollEnabled prop of the ScrollView component in React Native is used to enable or disable nested scrolling for Android devices. Nested scrolling is a feature that allows one scrolling view to be nested within another scrolling view, and have both views react to the touch events.

If you are trying to use nestedScrollEnabled with a ScrollView that has its horizontal prop set to true, it is important to note that this feature is not supported on Android. According to the React Native documentation:

“On Android, this is not supported because the native implementation is based on the ScrollView component, which does not support horizontal scrolling.”

Therefore, if you are trying to use nestedScrollEnabled with a horizontally scrolling ScrollView on Android, it will not have any effect.

One workaround for this issue is to use the FlatList component instead of ScrollView, as it does support horizontal scrolling and also has a nestedScrollEnabled prop that can be set to true.

DevTools: Profiler: Show which hooks changed

The Profiler tab in the React Developer Tools browser extension can be used to analyze the performance of a React application and identify areas that may be causing performance issues. One feature of the Profiler is the ability to see which Hooks have changed during a certain period of time.

To use this feature, you will need to have the React Developer Tools extension installed in your browser. Once the extension is installed, you can open the Profiler by clicking on the “Profiler” tab in the extension panel.

Next, you will need to wrap the part of your application that you want to profile with the Profiler component. The Profiler component takes a callback function as a prop, which will be called with performance measurements every time a render occurs.

Here is an example of how you can use the Profiler component to log the names of the Hooks that have changed during a render:

import { Profiler } from 'react';

const MyComponent = () => {
  const [state, setState] = useState(0);
  const [otherState, setOtherState] = useState(0);

  return (
    <Profiler
      id="MyComponent"
      onRender={(id, phase, actualDuration, baseDuration, startTime, commitTime) => {
        console.log('Changed Hooks:', React.__SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED.ReactCurrentDispatcher.current.getChangedHooks(startTime, commitTime));
      }}
    >
      <div>
        <button onClick={() => setState(state + 1)}>Increment</button>
        <button onClick={() => setOtherState(otherState + 1)}>Increment Other</button>
      </div>
    </Profiler>
  );
};

import React from 'react';
import { TextInput } from 'react-native';

const MyTextInput = () => {
  return (
    <TextInput
      blurOnSubmit={true}
    />
  );
};

Alternatively, you can try setting the dismissKeyboardOnPress prop of the TouchableWithoutFeedback component to true and wrapping the TextInput component in a TouchableWithoutFeedback component. This will cause the keyboard to be dismissed when the user taps anywhere outside the TextInput.

import React from 'react';
import { TextInput, TouchableWithoutFeedback } from 'react-native';

const MyTextInput = () => {
  return (
    <TouchableWithoutFeedback dismissKeyboardOnPress={true}>
      <TextInput />
    </TouchableWithoutFeedback>
  );
};

#include <array>

constexpr int foo() { return 42; }

int main()
{
  constexpr std::array<int, foo()> arr{};  // OK
  // const std::array<int, foo()> arr{};  // Error: CXX1405: 'constexpr' needed for the mark constant expression
  return 0;
}

<key>JSBundleURL</key>
<string>main.jsbundle</string>

The error message “Command PhaseScriptExecution failed with a nonzero exit code” typically occurs when building an iOS app using Xcode and indicates that the build process has failed. This can be caused by a variety of issues, such as syntax errors in your code, missing dependencies or frameworks, or problems with the build configuration.

Here are a few things you can try to troubleshoot the issue:

1. Check for syntax errors or runtime exceptions in your code: Make sure that your code is free of syntax errors and that all objects and resources are properly initialized and accessed.
2. Make sure you have all necessary dependencies and frameworks: Make sure that you have all necessary dependencies and frameworks included in your project and that they are up to date.
3. Check your build configuration: Make sure that your build settings are correct and that all necessary build phases are included.
4. Clean and rebuild your project: Try running Product > Clean and then rebuilding your project to see if this resolves the issue.

TouchableOpacity button is not working with absolute position + transform animation

It is possible that the TouchableOpacity button is not functioning properly when using absolute positioning and transform animation because the button’s hit box may not be accurately aligned with the visual element.

Here are a few things you can try to resolve this issue:

1. Use the hitSlop prop: The hitSlop prop allows you to specify an area around the button that should be considered part of the button’s hit box. You can use this prop to make the hit box larger, which may make it easier to interact with the button.
2. Use a View wrapper: You can wrap the TouchableOpacity button in a View element and apply the absolute positioning and transform animation to the View instead. This can help ensure that the hit box is accurately aligned with the visual element.
3. Use a TouchableWithoutFeedback component: If the TouchableOpacity button is not working as expected, you could try using a TouchableWithoutFeedback component instead. This component does not have a visual feedback effect when pressed, but it may be more reliable when used with absolute positioning and transform animation.

[Android] Error: Duplicate resources

The error message “Duplicate resources” typically occurs when building an Android app using Gradle and indicates that the build process has failed due to duplicate resource definitions. This can occur when the same resource is defined multiple times in different resource files or in different library dependencies.

Here are a few things you can try to resolve this issue:

1. Check for duplicate resource definitions: Make sure that you are not defining the same resource multiple times in different resource files or in different library dependencies.
2. Use the --debug flag when building: This can help provide more information about the source of the duplicate resource definitions.
3. Exclude duplicate resources: If you are using multiple library dependencies that define the same resource, you can try excluding the duplicate resource from one of the dependencies using the exclude directive in your app’s build.gradle file.
4. Clean and rebuild the project: Try running ./gradlew clean to clean the project and then rebuild it to see if this resolves the issue.

“VirtualizedLists should never be nested inside plain ScrollViews with the same orientation” error in console for FlatList/SectionList with scrollEnabled={false}

The error message “VirtualizedLists should never be nested inside plain ScrollViews with the same orientation” typically occurs when using a FlatList or SectionList inside a ScrollView with the scrollEnabled prop set to false. This can cause performance issues, as the ScrollView will attempt to render all items in the list, even though they are not scrollable.

To fix this issue, you can try one of the following solutions:

1. Remove the ScrollView wrapper: If possible, you can remove the ScrollView wrapper and use the FlatList or SectionList directly.
2. Set the scrollEnabled prop to true: If you need to use the ScrollView wrapper for some other reason, you can set the scrollEnabled prop to true to allow the list to be scrollable.
3. Use a VirtualizedList component: Instead of using a FlatList or SectionList, you can use a VirtualizedList component, which is optimized for rendering large lists and is designed to be used inside a ScrollView.

<video /> attribute needed but not guaranteed by React

The <video> element is a standard HTML element that is used to embed video content in a webpage. In React, you can use the <video> element just like you would use any other HTML element. However, it is important to note that the <video> element has a number of attributes that are required for it to function properly.

Some of the common attributes that are required for the <video> element to work are:

1. src: The src attribute specifies the URL of the video file to be played.
2. controls: The controls attribute specifies whether the video should have controls (such as play/pause buttons) or not.
3. type: The type attribute specifies the MIME type of the video file. This is used by the browser to determine which video player plugin or application to use to play the file.

It is important to include these attributes when using the <video> element in your React app to ensure that the video can be played correctly. If you do not include these attributes, the video may not function properly.

Android NDK issue while upgrading from 0.66.4 to 0.68.1

The Android NDK (Native Development Kit) is a toolset that allows you to build native code libraries for Android. If you are experiencing issues while upgrading from React Native 0.66.4 to 0.68.1, it is possible that the NDK version you are using is not compatible with the newer version of React Native.

To fix this issue, you can try one of the following solutions:

1. Upgrade the NDK: Make sure that you are using the latest version of the NDK, which is compatible with React Native 0.68.1. You can download the latest version of the NDK from the Android Developer website.
2. Downgrade React Native: If you are unable to upgrade the NDK or if you encounter other issues with the newer version of React Native, you may need to downgrade to a version that is compatible with your current NDK. You can find the available versions of React Native on the npm website.
3. Use a compatibility wrapper: If you need to use the newer version of React Native but are unable to upgrade the NDK, you may be able to use a compatibility wrapper, such as react-native-ndk, to allow the newer version of React Native to work with your current NDK.

Fast refresh not working in React Native 0.64.2

Fast refresh is a feature in React Native that allows you to make changes to your app’s code and see the results immediately without having to manually rebuild the app. If fast refresh is not working in your React Native app, there could be a few potential issues:

1. Fast refresh may not be enabled: Make sure that fast refresh is enabled in your app. In React Native 0.64.2, fast refresh can be enabled by adding the following lines to your app’s metro.config.js file:

module.exports = {
  resolver: {
    sourceExts: ['js', 'json', 'ts', 'tsx', 'jsx'],
  },
  transformer: {
    babelTransformerPath: require.resolve('react-native-fast-refresh/babel'),
  },
};

2. There may be syntax errors in your code: Fast refresh will not work if there are syntax errors in your code. Make sure that your code is free of syntax errors and that all objects and resources are properly initialized and accessed.
3. You may be using a version of React Native that does not support fast refresh: Fast refresh was introduced in React Native 0.63 and is not available in earlier versions. If you are using an earlier version of React Native, fast refresh will not be available.

App build has warning issues “Unable to strip the following libraries”

If you are seeing a warning message saying “Unable to strip the following libraries” while building your React Native app, it typically means that the build process was unable to remove unused code from one or more native libraries included in your app. This can increase the size of your app and may affect its performance.

To fix this issue, you can try one of the following solutions:

1. Upgrade to the latest version of React Native: Make sure that you are using the latest version of React Native, which may include fixes for this issue.
2. Exclude the library from the build: If you are using a third-party library that is causing this issue, you may be able to exclude it from the build by adding the following lines to your app’s build.gradle file:

packagingOptions {
  doNotStrip "*/*.so"
  doNotStrip "*/lib*.so"
  doNotStrip "*/lib*.a"
  doNotStrip "*/lib*.so.*"
}

3. Use the stripDebugSymbols flag: You can try setting the stripDebugSymbols flag to false in your app’s build.gradle file to disable the stripping of debug symbols from the native libraries:

buildTypes {
  release {
    stripDebugSymbols false
  }
}

HTTP Fetch fails with “TypeError: Network request failed” => Resolved

The error message “TypeError: Network request failed” typically occurs when making an HTTP request using the fetch function and indicates that the request has failed. This can be caused by a variety of issues, such as a network error, a security issue, or a problem with the server.

To resolve this issue, you can try the following:

1. Check your network connection: Make sure that you have a stable network connection and that the server you are trying to reach is online.
2. Check for security issues: If you are making an HTTP request to a server that uses SSL/TLS, make sure that the certificate is valid and trusted by your app.
3. Check the server configuration: Make sure that the server is configured correctly and that it is able to process the request.
4. Debug the request: Use a tool like Charles or Fiddler to capture and debug the HTTP request. This can help you identify any issues with the request or the server’s response.

EventEmitter.removeListener(‘change’, …): Method has been deprecated. Please instead use `remove()` on the subscription returned by `EventEmitter.addListener`.

The error message “EventEmitter.removeListener(‘change’, …): Method has been deprecated. Please instead use remove() on the subscription returned by EventEmitter.addListener” typically occurs when using the EventEmitter class in a React Native app and indicates that the removeListener method has been deprecated.

To resolve this issue, you can use the remove method on the subscription returned by EventEmitter.addListener instead of the removeListener method. Here is an example of how to do this:

import { EventEmitter } from 'react-native';

const eventEmitter = new EventEmitter();

const subscription = eventEmitter.addListener('change', (data) => {
  console.log(data);
});

// To remove the listener, use the `remove` method on the subscription object
subscription.remove();

borderColor (top left bottom right) styling ignored on Android

If you are using the borderColor style property in a React Native app and it is being ignored on Android, there could be a few potential issues:

1. The borderColor style is not supported on Android: Some style properties, such as borderColor, are not supported on all platforms. On Android, you can use the borderTopColor, borderLeftColor, borderBottomColor, and borderRightColor style properties to set the border color for each side of an element.
2. The borderColor style may be overridden by other styles: Make sure that the borderColor style is not being overridden by other styles that are applied to the element. You can use the StyleSheet.create method to create a style object with the borderColor style and apply it directly to the element to ensure that it is not overridden.
3. There may be a problem with the Android theme: If you are using a custom Android theme, it may be conflicting with the borderColor style. You can try switching to the default Android theme to see if this resolves the issue.

RN 0.60.5 iOS release build “No bundle URL present” after updating

The error message “No bundle URL present” typically occurs when building a React Native app for iOS and indicates that the build process is unable to locate the JavaScript bundle that is used to run the app. This can be caused by a variety of issues, such as a problem with the JavaScript bundle itself or a problem with the build configuration.

To resolve this issue, you can try the following:

1. Check the JavaScript bundle: Make sure that the JavaScript bundle is being generated correctly and that it is located in the correct directory. You can use the react-native bundle command to manually generate the bundle.
2. Check the build configuration: Make sure that the build configuration is correct and that it is pointing to the correct location of the JavaScript bundle. You can check the main.jsbundle entry in the Info.plist file to make sure it is correct.
3. Clean and rebuild the project: Try running ./gradlew clean to clean the project and then rebuild it to see if this resolves the issue.
4. Restart the packager: If the JavaScript bundle is being generated correctly but the app is still not working, you may need to restart the packager to pick up the changes. You can do this by running the react-native start --reset-cache command.

Fetching api response too slow when debugging mode is off

If you are experiencing slow performance when fetching an API response in a React Native app and the debugging mode is turned off, there could be a few potential issues:

1. Network issues: Make sure that you have a stable network connection and that the server you are trying to reach is online and responsive. You can use a tool like Charles or Fiddler to capture and debug the HTTP request to see if there are any issues with the network.
2. Server-side issues: If the server is slow to respond or is experiencing high load, it can cause the API request to be slow. You may need to contact the server administrator or optimize the server to improve performance.
3. Client-side issues: If the issue is on the client side, there could be a problem with the way the API request is being made. Make sure that you are using the fetch function correctly and that you are not making too many unnecessary requests. You can also try using a tool like the React Native Debugger to optimize your code and improve performance.

Android keyboard disappears when TextInput is behind the keyboard area

If you are experiencing an issue where the Android keyboard disappears when a TextInput element is behind the keyboard area, there could be a few potential issues:

1. The TextInput element may be obscured by other elements: Make sure that the TextInput element is not being obscured by other elements on the screen. You can use the zIndex style property to adjust the stacking order of the elements and ensure that the TextInput element is always visible.
2. The TextInput element may be positioned outside the visible area: Make sure that the TextInput element is positioned within the visible area of the screen. If the element is positioned outside the visible area, it may not be possible to focus on it.
3. The TextInput element may be disabled: Make sure that the TextInput element is not disabled by setting the disabled prop to false.
4. The keyboard may be set to hide automatically: Some keyboards are configured to hide automatically when a TextInput element loses focus. You can try disabling this behavior by setting the keyboardShouldPersistTaps prop on the parent ScrollView element to 'always'.

iOS unable to archive [RN 0.63.2] – Target ‘React-Core.common-AccessibilityResources’ has create directory command with output

If you are unable to archive a React Native app for iOS and are seeing the error message “Target ‘React-Core.common-AccessibilityResources’ has create directory command with output”, it may be due to a problem with the Xcode project configuration.

To resolve this issue, you can try the following:

1. Clean the project: Try cleaning the project by selecting “Product > Clean” from the Xcode menu. This can help resolve issues with the build process.
2. Check the build settings: Make sure that the build settings are correct and that all required frameworks and libraries are included.
3. Check for duplicate files: Make sure that there are no duplicate files in the project that may be causing issues with the build process.
4. Check for problems with the AccessibilityResources target: Make sure that the AccessibilityResources target is set up correctly and that it is not conflicting with other targets in the project.

clang: error: linker command failed with exit code 1 (use -v to see invocation)

If you are seeing the error message “clang: error: linker command failed with exit code 1 (use -v to see invocation)” while building a React Native app, it typically indicates that there was a problem linking the compiled object files into a single executable. This can be caused by a variety of issues, such as missing or incompatible libraries, duplicate symbols, or problems with the build configuration.

To resolve this issue, you can try the following:

1. Check for missing or incompatible libraries: Make sure that all required libraries are included in the project and that they are compatible with the current version of React Native.
2. Check for duplicate symbols: Make sure that there are no duplicate symbols in the project that may be causing issues with the linker. You can use the nm tool to list the symbols in an object file and search for duplicates.
3. Check the build configuration: Make sure that the build configuration is correct and that all required build settings are set correctly.
4. Clean and rebuild the project: Try running ./gradlew clean to clean the project and then rebuild it to see if this resolves the issue.

TypeError: Cannot read property ‘getItem’ of undefined

The error message “TypeError: Cannot read property ‘getItem’ of undefined” typically occurs when trying to access a property or method of an object that is undefined. This can happen if you are trying to access an object that has not been initialized or if the object is null.

To resolve this issue, you can try the following:

1. Make sure the object is defined: Make sure that the object you are trying to access is defined and has been initialized correctly.
2. Check for null values: Make sure that the object is not null before trying to access its properties or methods. You can do this by using an if statement to check for null values:

if (object !== null) {
  // access object properties or methods here
}

3. Check for typos: Make sure that you are spelling the object’s properties and methods correctly. Typos can cause this error to occur.

[Android] First TextInput focus automatically blurred

If you are experiencing an issue where the first TextInput element in a React Native app for Android is automatically blurred when the app starts, there could be a few potential issues:

1. The TextInput element may be obscured by other elements: Make sure that the TextInput element is not being obscured by other elements on the screen. You can use the zIndex style property to adjust the stacking order of the elements and ensure that the TextInput element is always visible.
2. The TextInput element may be disabled: Make sure that the TextInput element is not disabled by setting the disabled prop to false.
3. The TextInput element may be positioned outside the visible area: Make sure that the TextInput element is positioned within the visible area of the screen. If the element is positioned outside the visible area, it may not be possible to focus on it.
4. The TextInput element may be obscured by the keyboard: Make sure that the TextInput element is not obscured by the keyboard when it is displayed. You can use the keyboardShouldPersistTaps prop on the parent ScrollView element to ensure that the TextInput element is always visible.

[Only Android] fetch Error : [Network request failed]

The error message “fetch Error: [Network request failed]” typically occurs when making an HTTP request using the fetch function and indicates that the request has failed. This can be caused by a variety of issues, such as a network error, a security issue, or a problem with the server.

To resolve this issue on Android, you can try the following:

1. Check your network connection: Make sure that you have a stable network connection and that the server you are trying to reach is online.
2. Check for security issues: If you are making an HTTP request to a server that uses SSL/TLS, make sure that the certificate is valid and trusted by your app.
3. Check the server configuration: Make sure that the server is configured correctly and that it is able to process the request.
4. Debug the request: Use a tool like Charles or Fiddler to capture and debug the HTTP request. This can help you identify any issues with the request or the server’s response.
5. Check for Android-specific issues: There may be Android-specific issues that are causing the fetch request to fail. For example, if you are using the http scheme in the URL and the app is running on Android 9 or higher, the request may fail due to changes in the default network security configuration. You can fix this by using the https scheme instead.

FlatList onEndReached can not be called

There could be a few reasons why the onEndReached function of the FlatList component is not being called. Here are some things you could try:

1. Make sure that the onEndReached prop is properly set on the FlatList component.
2. Make sure that the FlatList is actually scrolling. You can do this by adding a large number of items to the list and checking if you can scroll to the bottom.
3. Make sure that the onEndReachedThreshold prop is set to a value greater than 0. This prop determines how close to the end of the list the user needs to be before onEndReached is called.
4. If you are using VirtualizedList instead of FlatList, make sure that the getItemCount prop is set correctly.
5. Make sure that the onEndReached function is properly defined and that it does not contain any syntax errors.
6. If the FlatList is inside a ScrollView or another component that handles scrolling, make sure that the onEndReached function is not being overridden by the parent component.

React 18 – Avoiding hydration errors, but initialize client-only state directly if possible

In React, hydration refers to the process of taking a server-rendered React application and “rehydrating” it on the client-side so that the client can take over and continue rendering the application.

If you are seeing hydration errors, it typically means that there is a discrepancy between the server-rendered HTML and the client-side React code. This can happen if the client-side React code is trying to render a different version of the application than what was rendered on the server.

To avoid hydration errors, you should make sure that the server-rendered HTML and the client-side React code are in sync. Here are a few things you can try:

1. Double-check that the version of React you are using on the server and the client are the same.
2. Make sure that you are using the same data to render the application on the server and the client.
3. If you are using any client-only state, try to initialize it directly on the client-side rather than relying on the server-rendered HTML. This can help avoid conflicts between the server-rendered HTML and the client-side React code.
4. If you are using server-side rendering and need to pass data from the server to the client, consider using window.__INITIAL_DATA__ to pass the data. This can help avoid conflicts between the server-rendered HTML and the client-side React code.

Hooks + multiple instances of React

React Hooks are a new feature in React that allow you to use state and other React features in functional components. If you are using React Hooks and you have multiple instances of React on the same page, you need to make sure that each instance has its own copy of the Hooks state.

One way to do this is to use the create-react-app package, which includes a configuration option called assetPrefix that allows you to specify a unique prefix for each instance of React. This ensures that each instance of React has its own copy of the Hooks state and prevents conflicts between the different instances.

Alternatively, you can use the useContext Hook to create a global context that can be shared between multiple instances of React. This allows you to maintain a single source of truth for the Hooks state, which can help avoid conflicts between the different instances.

how can we make ListHeaderComponent as sticky header in SectionList

To make the ListHeaderComponent of a SectionList component sticky, you can use the stickySectionHeadersEnabled prop. This prop is available as of React Native 0.50 and allows you to specify whether the section headers should be sticky or not.

Here is an example of how to use the stickySectionHeadersEnabled prop:

import React from 'react';
import { View, Text, SectionList } from 'react-native';

const App = () => {
  return (
    <SectionList
      sections={[
        {
          title: 'A',
          data: ['Alice', 'Andrew', 'Amy'],
        },
        {
          title: 'B',
          data: ['Bob', 'Bobby', 'Barbara'],
        },
      ]}
      renderItem={({ item }) => <Text>{item}</Text>}
      renderSectionHeader={({ section }) => (
        <Text>{section.title}</Text>
      )}
      stickySectionHeadersEnabled={true}
    />
  );
};

export default App;

This will make the section headers sticky and they will remain at the top of the list as the user scrolls.

Nested Text with onPress / TouchableOpacity Bug

It sounds like you’re having an issue with using onPress or TouchableOpacity within a nested text element in React Native.

Here are a few things to check that might help resolve the issue:

1. Make sure that you have wrapped the nested text element in a TouchableOpacity component.
2. Check that the onPress prop is properly attached to the TouchableOpacity component.
3. Make sure that the onPress prop is a function that is being passed to the TouchableOpacity component.
4. If the nested text element is within a View component, make sure that the View component has a touchable style applied to it, such as touchableOpacity or touchableHighlight.

Fetch API returns Network request failed on some websites.

There are a few reasons why a fetch request might fail with a “Network request failed” error in React Native. Here are a few things you can try to troubleshoot the issue:

1. Make sure that the URL you are trying to fetch is correct and properly formatted.
2. If you are trying to make a cross-origin request (i.e., a request to a different domain than the one that served your app), make sure that the server you are making the request to is set up to accept cross-origin requests. This typically involves setting the appropriate CORS headers on the server.
3. If you are using a self-signed certificate on the server you are making the request to, you may need to disable certificate verification in your fetch options. You can do this by setting the certificateVerify option to false in the fetch options object.
4. If the issue persists, try using a different network to make the request, or try using a tool like curl to make the request from the command line to see if the issue is specific to the React Native app or if it is a general network issue.

Facing white blank screen in iOS

A white blank screen can be caused by a variety of issues in a React Native app. Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have properly setup the iOS build environment. This includes installing Xcode, setting up Xcode command line tools, and installing the iOS simulator.
2. Check your Xcode project settings to make sure that the correct target is selected and that the correct development team is selected.
3. Make sure that you have properly installed and linked all of the dependencies and libraries in your project. You can use the react-native link command to link native dependencies, and make sure that the dependencies are correctly listed in your package.json file.
4. Make sure that you have properly configured your app’s main component (the component that is rendered by default when the app starts) in your index.js or App.js file.
5. Check your app’s log output for any error messages or warnings that might give you a clue about what is causing the white blank screen. You can view the log output in the Xcode console or by using the react-native log-ios command.

react-native init command won’t install TS template correctly

It sounds like you’re having an issue with the react-native init command not correctly installing the TypeScript template. Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have the latest version of the react-native-cli package installed. You can update it by running npm install -g react-native-cli.
2. If you are using a version of React Native that does not include the TypeScript template by default, make sure that you have installed the @react-native-community/cli-plugin-typescript plugin. You can install it by running npm install -g @react-native-community/cli-plugin-typescript.
3. If you have the TypeScript template installed and are still having issues, try creating a new React Native project using the TypeScript template and compare the project structure to your existing project. This can help you identify any missing or incorrect files that might be causing the issue.
4. If none of these suggestions help, you might want to try creating a new React Native project using the default template and then manually adding TypeScript to the project by following the instructions in the React Native documentation.

React native run android terribly slow

There are a few things that can cause the react-native run-android command to be slow. Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have the latest version of the Android SDK and emulator installed. You can update them by running sdkmanager and avdmanager from the command line.
2. If you are using a physical device to test your app, make sure that it is properly connected to your development machine and that you have enabled USB debugging in the developer options.
3. Make sure that you have correctly configured the ANDROID_HOME environment variable on your development machine. This should be set to the root directory of your Android SDK installation.
4. Try increasing the memory allocated to the emulator by editing the emulator options in the ~/.android/avd/{your_avd}.avd/config.ini file. You can increase the hw.ramSize option to give the emulator more memory.
5. If the issue persists, try creating a new Android virtual device (AVD) and running your app on that. This can help you determine if the issue is specific to your AVD or if it is a general issue with the react-native run-android command.

Modal make iOS app freeze when visible

It sounds like you’re having an issue with a modal causing your iOS app to freeze when it is visible. There are a few things you can try to troubleshoot this issue:

1. Make sure that the modal is being properly closed or dismissed when it is no longer needed. If the modal is being left open, it could be causing the app to freeze.
2. Check the modal component’s code to make sure that it is not causing any performance issues, such as an infinite loop or a large number of unnecessary re-renders.
3. If the modal is being used to display a large amount of data or a long list of items, consider optimizing the rendering of the data or using a virtualized list component to improve performance.
4. Make sure that you are not blocking the main thread with any long-running tasks or blocking operations when the modal is visible. This can cause the app to freeze.
5. If the issue persists, try using the iOS simulator’s debug mode to profile the app and identify any performance issues. You can also try using the react-native log-ios command to view the app’s log output and look for any error messages or warnings that might give you a clue about what is causing the app to freeze.

`npx react-native init` new application won’t run (React Native 0.66, macOS 11.6, Xcode 13.0)

It sounds like you’re having an issue getting a new React Native app to run using the npx react-native init command on macOS with Xcode 13.0. Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have the latest version of the react-native-cli package installed. You can update it by running npm install -g react-native-cli.
2. Make sure that you have correctly installed and configured the iOS build tools, including Xcode and the Xcode command line tools.
3. If you are using a physical device to test your app, make sure that it is properly connected to your development machine and that you have enabled USB debugging in the developer options.
4. Make sure that you have correctly configured the ANDROID_HOME environment variable on your development machine. This should be set to the root directory of your Android SDK installation.
5. If the issue persists, try creating a new React Native project using the default template and running that to see if the issue is specific to your project or if it is a general issue with the react-native init command.

[60.3] fetch issue [unable to parse json, unexpected token in json at position 1]

It sounds like you’re having an issue with the fetch API in React Native where you are unable to parse the JSON response due to an “unexpected token in JSON at position 1” error. There are a few things you can try to troubleshoot this issue:

1. Make sure that the server you are making the request to is returning valid JSON. You can use a tool like JSON Lint to check the JSON for syntax errors.
2. Make sure that you are properly handling the fetch response by calling the json method on the response object. You should also wrap the call to json in a try/catch block to handle any parsing errors.

try {
  const json = await response.json();
  // Do something with the JSON data
} catch (error) {
  // Handle parsing error
}

3. If the issue persists, try inspecting the raw response data to see if there are any unexpected characters or syntax errors in the JSON. You can do this by calling the text method on the response object instead of the json method and logging the result.

const text = await response.text();
console.log(text);

couldn’t find DSO to load: libjscexecutor.so caused by: dlopen failed: library “libjsc.so” not found

It sounds like you’re seeing an error in your React Native app that says “couldn’t find DSO to load: libjscexecutor.so caused by: dlopen failed: library “libjsc.so” not found”. This error is typically caused by a missing or corrupted library file on the device or emulator that your app is running on. Here are a few things you can try to troubleshoot the issue:

1. Make sure that you have the latest version of the React Native runtime installed on your device or emulator. You can update the runtime by running react-native upgrade.
2. If you are using a physical device to test your app, make sure that you have correctly installed and configured the Android SDK and any required drivers for your device.
3. If you are using an emulator, try creating a new emulator and running your app on that to see if the issue is specific to your current emulator.
4. If the issue persists, try cleaning the build artifacts for your app by running react-native clean. You can also try deleting the node_modules directory in your project and running npm install again to reinstall the dependencies.

gradlew assembleRelease produces warnings for basic react-native app with enabled Hermes

The presence of the warning messages could be due to various reasons. It could be that some of the dependencies in your app are not compatible with the version of React Native you are using, or there could be issues with the configuration of your app’s build files.

Here are a few things you can try to troubleshoot this issue:

1. Make sure that you have the latest version of React Native and all of its dependencies installed in your app.
2. Check the configuration of your app’s build files (e.g., build.gradle) and ensure that everything is set up correctly.
3. If you are using Hermes as your JavaScript engine, make sure that it is properly configured in your app.
4. Make sure that you have the latest version of the Android SDK and build tools installed on your machine.
5. If you are using third-party libraries or plugins in your app, make sure they are compatible with the version of React Native you are using.

TextInput prevent scroll on ScrollView

If you want to prevent a TextInput component from scrolling within a ScrollView, you can use the scrollEnabled prop to disable scrolling for the TextInput. Here’s an example:

<ScrollView>
  <TextInput scrollEnabled={false} />
  {/* other components */}
</ScrollView>

Alternatively, you can use a View component to wrap the TextInput and set the height prop to a fixed value to prevent the TextInput from taking up too much space and causing the ScrollView to scroll. Here’s an example:

<ScrollView>
  <View style={{ height: 100 }}>
    <TextInput />
  </View>
  {/* other components */}
</ScrollView>

Fetch call without a Content-Type throws a “Network request failed” error on Android

If you are making a fetch call in a React Native app and are seeing a “Network request failed” error on Android, it could be due to the fact that the server is not setting the Content-Type header in the response.

By default, the fetch function sets the Content-Type header to application/x-www-form-urlencoded when making a request. If the server is not expecting this header, it may return an error.

To fix this issue, you can try setting the <strong>Content-Type</strong> header to null when making the fetch call. This will prevent the Content-Type header from being sent with the request:

fetch(url, {
  method: 'POST',
  headers: {
    'Content-Type': null
  },
  body: JSON.stringify(data)
})
  .then((response) => response.json())
  .then((responseJson) => {
    // handle response
  })
  .catch((error) => {
    console.error(error);
  });

Alternatively, you can try setting the Content-Type header to a value that the server is expecting. For example, if the server is expecting a JSON payload, you can set the Content-Type header to application/json:

fetch(url, {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json'
  },
  body: JSON.stringify(data)
})
  .then((response) => response.json())
  .then((responseJson) => {
    // handle response
  })
  .catch((error) => {
    console.error(error);
  });

Android with RN 0.67.3 crashes when running custom build type with hermes enabled

If you are running a custom build type of a React Native app on Android with Hermes enabled, and the app is crashing, it could be due to an issue with the configuration of your app’s build files.

Here are a few things you can try to troubleshoot this issue:

1. Make sure that you have correctly configured your app’s build.gradle file to use Hermes as the JavaScript engine. You will need to add the following lines to your app’s build.gradle file:

android {
  ...
  defaultConfig {
    ...
    minSdkVersion 21
    ...
    // Enable Hermes for custom build type
    buildTypes {
      myCustomBuildType {
        ...
        ndk.abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
      }
    }
  }
  ...
}

dependencies {
  ...
  implementation 'com.facebook.hermes:hermes-engine:+'
}

2. Make sure that you are using a compatible version of React Native. Hermes is not compatible with all versions of React Native. It is recommended to use a version of React Native that is compatible with Hermes, such as 0.62.0 or higher.
3. Check the logcat output for any error messages that might provide more information about the cause of the crash.
4. If you are using third-party libraries or plugins in your app, make sure they are compatible with the version of React Native you are using.

TypeError: Super expression must either be null or a function

The “TypeError: Super expression must either be null or a function” error typically occurs when you are trying to extend a class in JavaScript, but you have not correctly called the parent class’s constructor function.

In a class-based component in React, you should always call the parent class’s constructor function in the child class’s constructor function using the super keyword, like this:

class ChildClass extends ParentClass {
  constructor(props) {
    super(props);
    // other initialization code goes here
  }
}

If you forget to include the call to super(props), you will get the “TypeError: Super expression must either be null or a function” error.

Here is an example of how you might use this pattern in a React component:

import React from 'react';

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      count: 0
    };
  }

  render() {
    return <div>{this.state.count}</div>;
  }
}

RN 0.63.4 main.jsbundle does not exist. This must be a bug with’

If you are seeing the error “main.jsbundle does not exist. This must be a bug with” when running a React Native app, it could be due to a problem with the way the app is being built or bundled.

Here are a few things you can try to troubleshoot this issue:

1. Make sure that you have run the react-native bundle command to create the main.jsbundle file for your app. This command should be run from the root directory of your app, and it will create the main.jsbundle file in the android or ios directory, depending on which platform you are building for.
2. If you are using a custom script to build your app, make sure that it is correctly generating the main.jsbundle file.
3. Check the logcat output for any error messages that might provide more information about the cause of the problem.
4. Make sure that you are using a compatible version of React Native. The main.jsbundle file was introduced in React Native 0.60, so if you are using an older version of React Native, this file may not exist.
5. If you are using third-party libraries or plugins in your app, make sure they are compatible with the version of React Native you are using.

Unable to find a specification for `React-Core (= 0.63.0)` depended upon by `React`

If you are seeing the error “Unable to find a specification for React-Core (= 0.63.0) depended upon by React” when trying to install dependencies in a React Native app, it could be due to an issue with the node_modules directory in your app.

Here are a few things you can try to troubleshoot this issue:

1. Try deleting the node_modules directory in your app and running npm install or yarn install again to reinstall the dependencies.
2. Make sure that you are using the correct version of the react and react-native packages in your app. The error message indicates that it is looking for a specific version of the React-Core package (0.63.0), which may not be compatible with the version of react or react-native that you are using.
3. If you are using a package-lock.json or yarn.lock file in your app, try deleting it and running npm install or yarn install again. These lockfiles can sometimes cause issues with dependency resolution.
4. If you are using third-party libraries or plugins in your app, make sure they are compatible with the version of React Native you are using.

onMouseEnter does not fire on an underlaying element if an element above is removed

In HTML, if an element is removed from the DOM while the mouse pointer is over it, the mouseleave event will be triggered on that element. This can have the effect of causing events on underlying elements to be missed.

To work around this behavior in a React app, you can try using the mouseover and mouseout events instead of onMouseEnter and onMouseLeave. These events will be triggered even if an element is removed from the DOM while the mouse pointer is over it.

Here is an example of how you might use these events in a React component:

import React, { useState } from 'react';

function MyComponent() {
  const [isHovered, setIsHovered] = useState(false);

  return (
    <div
      onMouseOver={() => setIsHovered(true)}
      onMouseOut={() => setIsHovered(false)}
    >
      {isHovered ? <div>I am being hovered!</div> : null}
    </div>
  );
}

[iOS] TextInput default text color change to white when running on real device

If you are seeing the text color of a TextInput component change to white when running your React Native app on a real iOS device, it could be due to a problem with the way the app is being built or the configuration of your app’s style sheets.

Here are a few things you can try to troubleshoot this issue:

1. Make sure that you are using the correct version of the react-native package in your app. There have been changes to the default styling of the TextInput component in different versions of React Native, so using an older version of the package could cause unexpected behavior.
2. Check the value of the color prop on your TextInput component. If the color prop is set to 'white', this could be causing the text color to change to white.
3. Make sure that you are not accidentally overwriting the default text color in your app’s style sheets. For example, if you have a global style that sets the color property to 'white', this could cause the text color of all text elements in your app to change to white.
4. Check the logcat output for any error messages that might provide more information about the cause of the problem.

Error: Unable to resolve module `./debugger-ui/debuggerWorker.aca173c4.js` from “:

If you are seeing the error “Error: Unable to resolve module ./debugger-ui/debuggerWorker.aca173c4.js from “” when running a React Native app, it could be due to a problem with the way the app is being built or bundled.

Here are a few things you can try to troubleshoot this issue:

1. Make sure that you have run the react-native bundle command to create the necessary JavaScript bundles for your app. This command should be run from the root directory of your app, and it will create the necessary bundles in the android or ios directories, depending on which platform you are building for.
2. If you are using a custom script to build your app, make sure that it is correctly generating the necessary JavaScript bundles.
3. Check the logcat output for any error messages that might provide more information about the cause of the problem.
4. Make sure that you are using a compatible version of React Native. The error message mentions a specific file (debuggerWorker.aca173c4.js), which may not be present in all versions of React Native.
5. If you are using third-party libraries or plugins in your app, make sure they are compatible with the version of React Native you are using.

React Native 0.63.3 app doesn’t install on Android 4.1

If you are having trouble installing a React Native app on an Android device running version 4.1, it could be due to compatibility issues with the version of React Native you are using.

React Native has dropped support for Android 4.1 as of version 0.60. If you are using a version of React Native that is newer than 0.60, it may not be compatible with Android 4.1.

To fix this issue, you can try using an older version of React Native that is compatible with Android 4.1, such as version 0.59.10. You can install this version by running the following command:

npm install --save react-native@0.59.10

Alternatively, you can try using a newer version of Android on your device. React Native supports Android 5.0 (API level 21) and higher.

Android app crashes on RN 0.60.5 with Hermes enabled

If you are seeing an Android app crash when using React Native 0.60.5 with Hermes enabled, it could be due to a problem with the configuration of your app’s build files or an issue with Hermes itself.

Here are a few things you can try to troubleshoot this issue:

1. Make sure that you have correctly configured your app’s build.gradle file to use Hermes as the JavaScript engine. You will need to add the following lines to your app’s build.gradle file:

android {
  ...
  defaultConfig {
    ...
    minSdkVersion 21
    ...
  }
  ...
}

dependencies {
  ...
  implementation 'com.facebook.hermes:hermes-engine:+'
}

2. Check the logcat output for any error messages that might provide more information about the cause of the crash.
3. If you are using third-party libraries or plugins in your app, make sure they are compatible with the version of React Native you are using.
4. If you are using a custom version of Hermes, make sure that it is compatible with React Native 0.60.5.

[0.62.0] Image with data:image/png;base64 crashing on iOS

If you are seeing an image with a data:image/png;base64 URI crashing on iOS when using React Native 0.62.0, it could be due to the size of the image.

React Native has a maximum size for images with data:image/png;base64 URIs, which is 3MB for iOS and 4MB for Android. If the image you are trying to display is larger than these limits, it will cause the app to crash.

To fix this issue, you can try reducing the size of the image by compressing it or using a lower resolution version. You can also try using a different image file format, such as JPEG, which has a larger maximum size limit.

Here is an example of how you might display an image with a data:image/png;base64 URI in a React Native app:

import React from 'react';
import { Image } from 'react-native';

function MyImage() {
  return (
    <Image
      source={{ uri: 'data:image/png;base64,<base64 encoded image data>' }}
    />
  );
}

Android application becomes super slow on startup after enabling Hermes

If you are experiencing a significant decrease in performance on Android after enabling Hermes in a React Native app, there could be a few possible causes.

Here are a few things you can try to troubleshoot this issue:

1. Make sure that you have correctly configured your app’s build.gradle file to use Hermes as the JavaScript engine. You will need to add the following lines to your app’s build.gradle file:

android {
  ...
  defaultConfig {
    ...
    minSdkVersion 21
    ...
  }
  ...
}

dependencies {
  ...
  implementation 'com.facebook.hermes:hermes-engine:+'
}

2. Check the logcat output for any error messages that might provide more information about the cause of the performance issue.
3. Make sure that you are using a compatible version of React Native. Hermes is not compatible with all versions of React Native, and using an incompatible version could cause performance issues.
4. If you are using third-party libraries or plugins in your app, make sure they are compatible with the version of React Native you are using.
5. Try reducing the size of your app’s JavaScript bundle by optimizing your code or using code-splitting techniques. A larger JavaScript bundle can increase the time it takes for the app to start up.

Unable to upload image file on first try getting TypeError: Network Request Failed

If you are seeing the error “TypeError: Network request failed” when trying to upload an image file in a React app, it could be due to a problem with the way the image file is being passed to the server.

Here are a few things you can try to troubleshoot this issue:

1. Make sure that the image file you are trying to upload is a valid image file. You can try opening the file in an image viewer to see if it is a valid image.
2. Check the content type of the image file you are trying to upload. If the content type is not set correctly, the server may not be able to process the file.
3. Make sure that you are using the correct API endpoint for uploading the image file. The endpoint should be able to accept file uploads and should be configured to handle the type of image file you are trying to upload.
4. Check the server logs for any error messages that might provide more information about the cause of the problem.
5. Make sure that you are using the correct HTTP method (e.g., POST, PUT, etc.) and the correct HTTP headers when making the request to upload the image file.

[DevTools Bug] Children cannot be added or removed during a reorder operation.

The error “Children cannot be added or removed during a reorder operation” typically occurs when you are trying to modify the children of a container component in React while a reorder operation is in progress.

In React, a “reorder operation” refers to any action that modifies the order of the children of a container component, such as moving a child component to a different position in the container or adding a new child component. During a reorder operation, React needs to update the indexes of the children to reflect their new positions. If you try to modify the children of the container during a reorder operation, it can cause conflicts with the reorder operation and lead to the “Children cannot be added or removed during a reorder operation” error.

To fix this issue, you can try moving the code that modifies the children of the container to a different point in your app’s rendering cycle. For example, you can try wrapping the code in a useEffect hook and setting the dependencies array to an empty array, like this:

import { useEffect } from 'react';

function MyComponent() {
  useEffect(() => {
    // code that modifies the children of the container goes here
  }, []);

  return <div>{/* container and children go here */}</div>;
}

Inverted FlatList displays activity indicator at the bottom

If you are using an inverted FlatList in a React Native app and the activity indicator is being displayed at the bottom of the list instead of at the top, it could be due to a problem with the way the list is being rendered.

In an inverted FlatList, the items are rendered in reverse order, with the last item in the list being displayed at the top. The activity indicator, which is displayed at the end of the list when the list is being refreshed or loading more data, is also rendered in reverse order, which causes it to be displayed at the top of the list instead of at the bottom.

To fix this issue, you can try using a regular (non-inverted) FlatList, or you can try using the invertStickyHeaders prop to invert the rendering of the activity indicator. This prop is available in React Native 0.61 and higher.

Here is an example of how you might use the invertStickyHeaders prop in a React Native app:

import { FlatList } from 'react-native';

function MyList() {
  return (
    <FlatList
      inverted
      invertStickyHeaders
      data={[/* list data goes here */]}
      renderItem={/* render function goes here */}
      keyExtractor={/* key extractor function goes here */}
      onRefresh={/* refresh function goes here */}
      refreshing={/* boolean indicating whether list is refreshing goes here */}
      onEndReached={/* function to load more data goes here */}
      onEndReachedThreshold={0.5}
    />
  );
}

More issues from Facebook repos

Troubleshooting facebook-create-react-app | Troubleshooting facebook-jest | Troubleshooting facebook-metro | Troubleshooting facebook-prophet | Troubleshooting facebook-flipper

The post Troubleshooting Common Issues in Facebook React appeared first on Lightrun.

When attempting to install certain dependencies, specifically numpydoc==0.8.0 and overrides==1.9, using the latest version from the master branch of pipenv, I encountered a failure with the message “Will try again.” Although pipenv notified me that it was “Installing initially failed dependencies…” it did not provide any feedback regarding whether the installation was successful or not. The installation command used was pipenv install --python 3.7. The following is an excerpt from the installation log:

...
Installing dependencies from Pipfile.lock (53751d)…
An error occurred while installing numpydoc==0.8.0 --hash=sha256:61f4bf030937b60daa3262e421775838c945dcdd6e4854c7eb5ffd! Will try again.
An error occurred while installing overrides==1.9 --hash=sha256:91b59ac1f6f38aae1531f5d6111033b8f4d7e59330078202567963! Will try again.
...
Installing initially failed dependencies…

As shown in the log, the installation process indicated that it would try again for the failed dependencies, but it did not provide any conclusive information regarding the success or failure of the retry.

Getting a sense of what’s actually happening inside a live application is a frustrating experience, one that relies mostly on querying and observing whatever logs were written during development.
Lightrun is a Developer Observability Platform, allowing developers to add telemetry to live applications in real-time, on-demand, and right from the IDE.

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Problem solution for: pipenv does not give feedback on installing initially failed dependencies.

To address the issue of not receiving clear feedback on the success or failure of dependency installations when using the latest version of pipenv, there are a few steps you can take:

1. Update pipenv: Ensure that you have the latest version of pipenv installed. You can do this by running the following command:

pip install --upgrade pipenv

1. Retry the installation: Run the pipenv install command again to attempt the installation of the dependencies. Monitor the output for any error messages or indications of success. If the installation fails again without clear feedback, proceed to the next step.
2. Verify the installation: Use the pipenv --venv command to check if the virtual environment was successfully created. This command displays the path to the project’s virtual environment directory. If the virtual environment exists, it indicates that the installation was successful.
3. Activate the virtual environment: If the virtual environment was created, activate it using the pipenv shell command. This command activates the virtual environment and allows you to work within its isolated environment. Once activated, you can verify that the dependencies are correctly installed by using commands such as pip list to view the installed packages.

By following these steps, you can ensure that the dependencies are installed correctly and have clear feedback on the success or failure of the installation process. If the issue persists, it may be helpful to consult the pipenv documentation or seek assistance from the pipenv community to troubleshoot further.

Problem 1: Slow Installation with Pipenv

One common problem with Pipenv is slow package installation, particularly when dealing with large projects or a slow internet connection. This can lead to frustration and decreased development productivity. The slow installation can be caused by various factors, including network latency, dependency resolution, or inefficient caching.

Solution:

To address the slow installation issue with Pipenv, you can try the following solutions:

1. Use a Local Mirror: Configuring Pipenv to use a local mirror for package downloads can significantly improve installation speed. This involves setting the PIPENV_PYPI_MIRROR environment variable to the URL of the local mirror. For example:

export PIPENV_PYPI_MIRROR=https://your-local-mirror-url

2. Clear Pipenv Cache: Pipenv caches downloaded packages to speed up future installations. However, an overly large cache can slow down the installation process. You can clear the Pipenv cache using the --clear option:

pipenv --clear

3. Optimize Dependency Resolution: Pipenv performs dependency resolution based on the specified versions and constraints in the Pipfile.lock. However, complex dependency graphs or conflicting requirements can lead to longer resolution times. To optimize dependency resolution, ensure that your Pipfile specifies precise version constraints and avoids overly broad ranges.

Problem 2: Conflict Resolution in Pipenv

Another common problem with Pipenv is resolving conflicts between package dependencies. When multiple packages require different versions of the same dependency or have incompatible dependencies, Pipenv may fail to resolve the conflicts, resulting in installation errors.

Solution:

To resolve conflicts in Pipenv, you can take the following steps:

1. Update Package Versions: Ensure that you have the latest versions of the packages specified in your Pipfile. Run the following command to update packages:

pipenv update

2. Adjust Version Constraints: Review the version constraints specified in your Pipfile for conflicting packages. Consider relaxing or tightening the version ranges to find a compatible set of dependencies. You can also use explicit versions to avoid ambiguity.
3. Use Pipenv’s Resolution Strategies: Pipenv provides different resolution strategies, such as --pre to allow pre-release versions or --skip-lock to skip resolving dependencies from the Pipfile.lock. Experimenting with different strategies may help resolve conflicts in certain cases.

Problem 3: Pipenv Installation Errors on Windows

Windows users may encounter specific installation errors when using Pipenv due to differences in package management and system configurations.

Solution:

To address Pipenv installation errors on Windows, consider the following steps:

1. Install Required System Dependencies: Ensure that the required system dependencies, such as Python and Visual C++ Build Tools, are installed correctly on your Windows machine. Refer to the official Pipenv documentation for the specific requirements.
2. Use Python Launcher: On Windows, you can try using the Python Launcher (py) to execute Pipenv commands. This helps ensure that Pipenv is using the correct Python interpreter and associated dependencies.

py -m pipenv install

3. Use Python 3.7 or Later: Pipenv is designed to work best with Python 3.7 and later versions. If you are using an older Python version, consider upgrading to a newer version to avoid compatibility issues.

By following these solutions, you can mitigate common problems encountered while using Pipenv. However, it’s important to keep in mind that specific issues may require additional troubleshooting or consultation with the Pipenv community or official documentation.

A brief introduction to pipenv

Pipenv is a popular package manager for Python that aims to provide a streamlined and efficient workflow for managing project dependencies, virtual environments, and dependency resolution. It combines the functionality of pip (the package installer) and virtualenv (the virtual environment manager) into a single tool. Pipenv utilizes the Pipfile and Pipfile.lock files to define and track project dependencies, ensuring reproducible and deterministic installations.

One of the key features of Pipenv is its automatic creation and management of virtual environments. It automatically creates a dedicated virtual environment for each project, isolating the project’s dependencies from the global Python environment. This allows for a clean and controlled development environment. Pipenv also provides commands to activate and deactivate the virtual environment, making it easy to switch between different projects.

Additionally, Pipenv simplifies dependency management by introducing a more user-friendly syntax in the Pipfile. It supports specifying packages and their versions using concise and intuitive syntax, allowing developers to declare dependencies with precision. Pipenv also integrates with PyPI (Python Package Index) to fetch and install packages from the official repository. By leveraging the Pipfile.lock file, Pipenv ensures that the exact versions of dependencies are installed, providing reproducibility across different environments.

In summary, Pipenv offers a robust and convenient solution for managing Python project dependencies and virtual environments. With its combined functionality of pip and virtualenv, automatic virtual environment creation, and dependency resolution based on the Pipfile.lock, Pipenv simplifies the development workflow and helps ensure reliable and consistent installations of Python packages.

Most popular use cases pipenv

1. Dependency Management: Pipenv excels at managing project dependencies by providing a straightforward and intuitive syntax for specifying dependencies in the Pipfile. Developers can declare dependencies along with their desired versions, enabling precise control over the package ecosystem. Here’s an example of declaring dependencies in a Pipfile:

[[source]]
url = "https://pypi.org/simple"
verify_ssl = true
name = "pypi"

[packages]
requests = "==2.25.1"
numpy = ">=1.19.0,<2.0.0"

[dev-packages]
pytest = "^6.2.4"

2. Virtual Environment Management: Pipenv simplifies the management of virtual environments by automatically creating and isolating project-specific virtual environments. This ensures that project dependencies are installed in a dedicated environment, separate from the system-wide Python installation. Developers can easily activate the virtual environment using the pipenv shell command, as shown below:

$ pipenv shell
Launching subshell in virtual environment...
...
(PyLT3-Akadaxte) $

3. Reproducible Installations: With the help of the Pipfile.lock file, Pipenv enables reproducible installations of project dependencies. The Pipfile.lock file contains the exact versions of the installed packages, ensuring consistency across different development and deployment environments. When running pipenv install, Pipenv reads the Pipfile.lock to fetch and install the specified package versions, guaranteeing that the project’s dependencies are identical across different environments. This promotes reproducibility and reduces the likelihood of dependency-related issues.

Overall, Pipenv provides a comprehensive solution for dependency management and virtual environment handling in Python projects. Its user-friendly syntax, automatic virtual environment creation, and support for reproducible installations make it a valuable tool for developers seeking a streamlined and reliable package management workflow.

The post pipenv does not give feedback on installing initially failed dependencies. appeared first on Lightrun.

When using Feign, a declarative web service client, in combination with Spring annotations, a problem arises when trying to specify the “produces” value for a request that expects to accept “text/plain” content. In the following code snippet, the @PostMapping annotation is used to define an endpoint “/demo” that consumes “application/json” and produces “text/plain”:

@PostMapping(value = "/demo", consumes = "application/json", produces = "text/plain")
public String demo(@RequestBody List<Long> ids) {
    // Method implementation
}

However, despite explicitly setting the “produces” value to “text/plain”, the request header “Accept” still contains “application/json”. This behavior indicates that the “produces” value is not being applied correctly. As a result, the server may not respond with the expected “text/plain” content type, leading to unexpected behavior or errors.

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Problem solution for: Can’t set Content-type for Request Header when use Spring annotations

To address this issue, it is necessary to ensure that the “produces” value is correctly applied to the Feign client and the server-side endpoint. One potential solution is to modify the Feign client configuration to explicitly set the “Accept” header value to “text/plain” for the corresponding request. The following code snippet demonstrates how this can be achieved:

@FeignClient(name = "demoClient", url = "http://example.com", configuration = DemoClientConfiguration.class)
public interface DemoClient {
    @PostMapping(value = "/demo", consumes = "application/json", produces = "text/plain")
    @Headers("Accept: text/plain")
    String demo(@RequestBody List<Long> ids);
}

By explicitly specifying the “Accept” header value using the @Headers annotation, the Feign client will send the correct “Accept” header to the server, indicating that it expects “text/plain” content in the response. This helps ensure that the server processes the request according to the desired content type.

Problem 1: One common issue encountered when using Feign, a declarative web service client, is handling error responses returned by the server. By default, Feign treats any non-2xx HTTP response code as an error and throws a FeignException. However, the exception may not provide sufficient information about the specific error that occurred, making it challenging to handle and process the error appropriately.

@FeignClient(name = "exampleClient", url = "http://example.com")
public interface ExampleClient {
    @GetMapping("/api/resource")
    String getResource();
}

To address this problem, you can customize the Feign error decoder to extract relevant information from the error response and provide a more meaningful exception. This can be achieved by implementing the ErrorDecoder interface and overriding the decode() method. Here’s an example of a custom error decoder that extracts the error message from the response body:

public class CustomErrorDecoder implements ErrorDecoder {
    private final ErrorDecoder defaultErrorDecoder = new Default();

    @Override
    public Exception decode(String methodKey, Response response) {
        if (response.status() == HttpStatus.BAD_REQUEST.value()) {
            String errorMessage = extractErrorMessage(response.body());
            return new CustomException(errorMessage);
        }
        
        // Delegate to the default error decoder for other error codes
        return defaultErrorDecoder.decode(methodKey, response);
    }

    private String extractErrorMessage(Response.Body body) {
        // Extract the error message from the response body
        // Implement your logic here
    }
}

By implementing a custom error decoder, you can extract specific details from the error response and throw a custom exception that encapsulates the relevant information. This allows for more effective error handling and troubleshooting in your Feign client.

Problem 2: Another common problem with Feign is dealing with complex request payloads or handling dynamic parameters in the request. Feign provides support for sending GET, POST, PUT, and DELETE requests, but it may not be immediately obvious how to pass complex data structures or dynamically construct the request URL.

@FeignClient(name = "exampleClient", url = "http://example.com")
public interface ExampleClient {
    @PostMapping("/api/resource")
    void createResource(ResourceRequest request);
}

One solution to this problem is to leverage Feign’s support for parameter annotations, such as @RequestBody and @RequestParam. These annotations allow you to specify the request payload and query parameters in a more structured manner. Here’s an example:

@FeignClient(name = "exampleClient", url = "http://example.com")
public interface ExampleClient {
    @PostMapping("/api/resource")
    void createResource(@RequestBody ResourceRequest request, @RequestParam("param") String param);
}

In this example, the @RequestBody annotation is used to pass the request payload, while the @RequestParam annotation is used to include a query parameter in the request URL. By using these annotations appropriately, you can handle complex request payloads and dynamic parameters in a more structured and maintainable way.

Problem 3: Feign may encounter issues with long request URLs or parameters exceeding the URL length limit imposed by the server or the HTTP specification. This can result in HTTP 414 (URI Too Long) errors or incomplete requests.

To overcome this problem, you can configure Feign to use HTTP POST with a request body instead of GET for requests with long URLs or large parameters. This allows you to send the data in the request body instead of appending it to the URL.

@FeignClient(name = "exampleClient", url = "http://example.com")
public interface ExampleClient {
    @RequestMapping(value = "/api/resource", method = RequestMethod.POST)
    void getResource(@RequestParam("param") String param, @RequestBody LargeRequestBody requestBody);
}

By using POST instead of GET and passing the large data in the request body, you can avoid the URL length limitation and ensure the successful transmission of the request to the server.

These are just a few examples of common problems encountered when using Feign and potential solutions to address them. By understanding these challenges and implementing appropriate solutions, you can enhance the reliability and effectiveness of your Feign-based web service clients.

A brief introduction to feign

Feign is a declarative web service client developed by Netflix that simplifies the integration of RESTful APIs into Java applications. It provides a higher-level, annotation-based approach for defining and consuming HTTP-based services, allowing developers to focus on the functionality of their applications rather than dealing with low-level HTTP client code. With Feign, developers can easily make HTTP requests to remote services and map the responses to Java objects, reducing the boilerplate code typically associated with manual HTTP communication.

Feign leverages the power of annotations to define the API contract and configuration details. By using annotations such as @FeignClient, @GetMapping, @PostMapping, and others, developers can express the desired API endpoints and HTTP methods in a concise and intuitive manner. Feign also integrates seamlessly with other popular libraries in the Java ecosystem, such as Spring Cloud and Spring Boot, enabling the creation of robust and scalable microservices architectures. Additionally, Feign supports advanced features like request and response interception, error handling, and request retries, providing developers with flexible and extensible options for building resilient and reliable web service clients.

In summary, Feign offers a convenient and efficient way to consume RESTful APIs in Java applications. Its declarative and annotation-based approach reduces the complexity of working with HTTP requests and responses, allowing developers to focus on business logic and application functionality. With its integration capabilities and support for advanced features, Feign is a powerful tool for building robust and scalable microservices architectures in the Java ecosystem.

Most popular use cases feign

1. Service Integration: Feign can be used to integrate and consume RESTful services in Java applications. By defining interfaces with appropriate annotations, developers can easily interact with remote APIs and perform HTTP operations such as GET, POST, PUT, and DELETE. Feign abstracts away the complexities of low-level HTTP client code and provides a higher-level abstraction for making service calls. Here’s an example of how Feign interface can be defined to interact with a RESTful API:

@FeignClient(name = "myApiClient", url = "https://api.example.com")
public interface MyApiClient {
    @GetMapping("/users/{id}")
    User getUserById(@PathVariable("id") Long id);

    @PostMapping("/users")
    User createUser(@RequestBody User user);
}

2. Load Balancing and Service Discovery: Feign integrates seamlessly with service discovery mechanisms and load balancing libraries, making it suitable for building scalable and resilient microservices architectures. By leveraging technologies like Spring Cloud and Netflix Eureka, Feign can automatically discover available service instances and distribute requests across them. This allows developers to build distributed systems that can dynamically adapt to changes in the service topology. Feign’s integration with load balancing libraries like Ribbon provides additional flexibility in load distribution. Here’s an example of using Feign with Spring Cloud and Eureka:

@FeignClient(name = "myService", fallback = MyServiceFallback.class)
@RibbonClient(name = "myService")
public interface MyServiceClient {
    @GetMapping("/api/data")
    String getData();
}

3. Advanced Features and Extensibility: Feign offers advanced features and extensibility options to cater to various use cases. It supports features like request and response interception, allowing developers to customize the behavior of service calls. Feign also provides error handling mechanisms, enabling graceful handling of exceptions and error responses from the remote service. Developers can extend Feign’s functionality by implementing custom interceptors, error handlers, and decoders. This level of flexibility empowers developers to adapt Feign to their specific requirements and integrate it seamlessly into their application architecture.

The post Can’t set Content-type for Request Header when use Spring annotations appeared first on Lightrun.

We are utilizing Material-UI as the foundation for our project but encountering challenges when attempting to extend its components. Initially, we imported the Link component from @material-ui/core and assigned it to HnLink, which worked without any issues. However, problems arose when we tried to extend the Link component by defining our own component, HnLink, with additional functionality and explicitly specifying the LinkProps. This resulted in TypeScript errors indicating that the component and to prop were not being accepted. The same problem occurred with the Tabs component, where wrapping it in our custom component caused the onChange prop to not be accepted. This issue has also been raised and discussed in detail on the Material-UI GitHub repository.

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Problem solution for: The correct way to extend a Material UI component

To address the typing issues when wrapping Material-UI components, it is important to ensure that the extended component’s props are compatible with the original component’s props. One potential approach is to create a new component that extends the Material-UI component but omits or modifies the props causing the TypeScript errors. This can be achieved by defining a new component that explicitly specifies the desired props and passes the remaining props to the original component.

import { Link, LinkProps } from "@material-ui/core";

export const HnLink: React.FC<Omit<LinkProps, "to"> & { to: string }> = ({ to, ...restProps }) => {
  // Some extra functionality
  return <Link href={to} {...restProps} />
}
// Custom HnLink component with adjusted props

By using the Omit utility type, we can exclude the to prop from the LinkProps and add a new to prop with the desired type. This allows us to create a modified version of the Link component that accepts the necessary props without triggering TypeScript errors.

It is important to note that this solution may vary depending on the specific component and props being extended. Consulting the Material-UI documentation and community resources, such as the GitHub repository and forums, can provide additional insights and best practices for properly wrapping and extending Material-UI components to alleviate typing issues.

Problem 1: One common problem encountered when using Material-UI is the difficulty of customizing the styling of components. While Material-UI provides a wide range of pre-defined styles and themes, modifying these styles to align with specific design requirements can be challenging. For example, let’s consider the scenario of customizing the color palette of a Material-UI button component. By default, Material-UI buttons adhere to the theme’s primary color. However, when attempting to change the button color to a custom color, users may face issues and struggle to achieve the desired outcome.

Code Block 1:

import Button from "@material-ui/core/Button";
import { makeStyles } from "@material-ui/core/styles";

const useStyles = makeStyles(theme => ({
  customButton: {
    backgroundColor: "red", // Custom color
    color: "white",
  },
}));

const MyButton = () => {
  const classes = useStyles();

  return (
    <Button className={classes.customButton}>
      Custom Button
    </Button>
  );
};

Solution: To address customization challenges, Material-UI provides several approaches. One method involves leveraging the makeStyles hook to define custom styles for components. By creating a custom CSS class and applying it to the component, users can override the default styles and apply their desired modifications.

Code Block 2:

import Button from "@material-ui/core/Button";
import { makeStyles } from "@material-ui/core/styles";

const useStyles = makeStyles(theme => ({
  customButton: {
    backgroundColor: "red", // Custom color
    color: "white",
  },
}));

const MyButton = () => {
  const classes = useStyles();

  return (
    <Button className={classes.customButton}>
      Custom Button
    </Button>
  );
};

In the above example, the makeStyles hook is used to define the customButton class with custom styles, such as a red background color and white text color. By applying this class to the Button component, the customization is achieved.

Problem 2: Another common problem faced when working with Material-UI is the difficulty of handling complex layouts and responsive designs. Material-UI offers various layout components like Grid and Container to assist with layout management. However, when dealing with intricate layouts involving nested components and different screen sizes, achieving the desired responsive behavior can become challenging.

Code Block 3:

import Grid from "@material-ui/core/Grid";

const MyComponent = () => {
  return (
    <Grid container spacing={2}>
      <Grid item xs={12} md={6}>
        {/* Content */}
      </Grid>
      <Grid item xs={12} md={6}>
        {/* Content */}
      </Grid>
    </Grid>
  );
};

Solution: To address complex layout challenges, Material-UI offers a flexible and powerful grid system based on the CSS Grid specification. By using the Grid component, users can create responsive layouts that adapt to different screen sizes. The xs, md, and other size breakpoints can be used to define the desired layout arrangement.

Code Block 4:

import Grid from "@material-ui/core/Grid";

const MyComponent = () => {
  return (
    <Grid container spacing={2}>
      <Grid item xs={12} md={6}>
        {/* Content */}
      </Grid>
      <Grid item xs={12} md={6}>
        {/* Content */}
      </Grid>
    </Grid>
  );
};

In the provided example, the Grid component is used to create a two-column layout where each column occupies half the width on medium-sized screens (md={6}) and takes up the full width on small screens (xs={12}). By utilizing the grid system effectively, users can achieve the desired responsive behavior and manage complex layouts efficiently.

Problem 3: A frequent challenge faced when using Material-UI is the limited number of pre-built components available. While Material-UI offers a comprehensive set of components, there might be cases where users require additional or specialized components that are not readily available in the library. This limitation can lead to development bottlenecks and necessitate custom component implementation, consuming additional time and effort.

Solution: To address the need for additional or specialized components, Material-UI provides the flexibility to create custom components tailored to specific requirements. Users can leverage the available building blocks provided by Material-UI, such as the Box, Typography, and IconButton components, to construct custom components that align with their design needs. By combining these foundational components and utilizing the various styling and theming options provided by Material-UI, developers can create reusable and customized components that extend the functionality of the library.

It is important to note that Material-UI also has a vibrant and active community that contributes to the library by creating and sharing additional components, extensions, and plugins. Exploring community-driven resources, such as GitHub repositories and forums, can help users discover ready-to-use components that address specific use cases and expand the available options within the Material-UI ecosystem.

A brief introduction to material-ui

Material-UI is a popular React UI library that provides a rich set of pre-designed components and utilities for building user interfaces. It follows the principles of Material Design, Google’s design language, to create visually appealing and responsive web applications. Material-UI offers a comprehensive collection of reusable components, including buttons, inputs, dialogs, grids, and navigation elements, allowing developers to quickly construct modern and intuitive user interfaces.

One of the key features of Material-UI is its emphasis on theming and customization. It provides a robust theming system that allows developers to easily modify the appearance and behavior of components to match their project’s branding and design requirements. By utilizing the Material-UI theme object, users can customize colors, typography, spacing, and other visual aspects of the components, ensuring a consistent and cohesive look throughout the application. Additionally, Material-UI offers various ways to style components, such as using CSS-in-JS with the makeStyles or styled APIs, or applying global styles with the ThemeProvider.

Material-UI also places a strong emphasis on responsiveness and accessibility. It provides responsive components and layout systems that adapt to different screen sizes and orientations, enabling developers to create applications that work seamlessly across various devices. The library adheres to web accessibility standards and guidelines, ensuring that components are keyboard-navigable and provide proper semantic markup for assistive technologies. Material-UI also offers built-in support for internationalization and localization, allowing developers to create multilingual applications with ease. With its focus on theming, customization, responsiveness, accessibility, and internationalization, Material-UI empowers developers to build visually appealing and inclusive web applications.

Most popular use cases for material-ui

1. Material-UI provides a wide range of ready-to-use UI components that can be easily integrated into React applications. These components offer a consistent and visually appealing user interface, saving developers time and effort in designing and implementing UI elements from scratch. For example, the following code demonstrates the usage of a Material-UI button component:

import React from 'react';
import Button from '@material-ui/core/Button';

const MyButton = () => {
  return (
    <Button variant="contained" color="primary">
      Click Me
    </Button>
  );
};

2. Material-UI offers a powerful theming system that allows developers to customize the look and feel of their applications. By leveraging the Material-UI theme object, developers can easily override default styles, define custom colors, typography, and spacing, and create a consistent visual identity for their application. The following code snippet showcases how to customize the theme in Material-UI:

import React from 'react';
import { createMuiTheme, ThemeProvider } from '@material-ui/core/styles';
import Button from '@material-ui/core/Button';

const theme = createMuiTheme({
  palette: {
    primary: {
      main: '#007bff',
    },
  },
});

const MyThemedButton = () => {
  return (
    <ThemeProvider theme={theme}>
      <Button variant="contained" color="primary">
        Themed Button
      </Button>
    </ThemeProvider>
  );
};

3. Material-UI supports responsive design principles, allowing developers to create applications that adapt to different screen sizes and orientations. The responsive components and layout systems provided by Material-UI ensure that the application’s UI remains consistent and functional across various devices. Developers can utilize responsive grid components and breakpoints to create responsive layouts. For instance, the following code demonstrates the usage of Material-UI’s responsive grid system:

import React from 'react';
import Grid from '@material-ui/core/Grid';

const MyResponsiveLayout = () => {
  return (
    <Grid container spacing={2}>
      <Grid item xs={12} sm={6} md={4}>
        {/* Content */}
      </Grid>
      <Grid item xs={12} sm={6} md={4}>
        {/* Content */}
      </Grid>
      <Grid item xs={12} sm={6} md={4}>
        {/* Content */}
      </Grid>
    </Grid>
  );
};

By leveraging these features, developers can create sophisticated and responsive user interfaces with ease using Material-UI.

The post The correct way to extend a Material UI component appeared first on Lightrun.

Issue Description: There is an issue with downloading a 16GB zip file from Google Drive using the gdown command. The file’s unique identifier is provided in the command, and the permissions for the file have been set to “Anyone with the link.” However, when attempting to download the file, a “Permission denied” error occurs, indicating that there may be a need to adjust the permissions for “Anyone with the link.”

Error Message: The following error message is encountered when executing the gdown command with the Google Drive file URL: Permission denied: https://drive.google.com/uc?id=1InfIal4y7OBMGNUDeldEmDxtD0MrewY8. This error suggests that the current permission settings do not allow for downloading the file even though it is shared with “Anyone with the link.” It is recommended to verify and potentially modify the permissions to ensure proper access.

Getting a sense of what’s actually happening inside a live application is a frustrating experience, one that relies mostly on querying and observing whatever logs were written during development.
Lightrun is a Developer Observability Platform, allowing developers to add telemetry to live applications in real-time, on-demand, and right from the IDE.

• Instantly add logs to, set metrics in, and take snapshots of live applications
• Insights delivered straight to your IDE or CLI
• Works where you do: dev, QA, staging, CI/CD, and production

Start for free today

Problem solution for: Permission denied … Maybe you need to change permission over ‘Anyone with the link’?

To resolve the “Permission denied” error when attempting to download a file from Google Drive using the gdown command, you can follow these steps:

1. Verify Permissions: Double-check the permissions of the file to ensure that it is indeed set to “Anyone with the link.” This can be done by accessing the file in Google Drive, clicking on the “Share” button, and confirming that the sharing settings allow anyone with the link to access the file.
2. Update Permission Settings: If the permissions are not correctly configured, update them to grant access to “Anyone with the link.” This can be done by adjusting the sharing settings of the file in Google Drive and ensuring that the appropriate permission level is selected.
3. Retry the Download: After confirming and adjusting the permissions, retry the gdown command to download the file. Use the same command with the updated Google Drive file URL. For example:

gdown https://drive.google.com/uc?id=1InfIal4y7OBMGNUDeldEmDxtD0MrewY8

By ensuring that the file permissions are correctly set to allow access for “Anyone with the link” and retrying the download command, you should be able to successfully download the 16GB zip file from Google Drive.

Problem 1: SSL Certificate Verification Error

When using the gdown command to download a file from a URL, you may encounter an SSL certificate verification error. This error occurs when the SSL certificate of the target server cannot be verified. Here’s an example of the error message:

HTTPSConnectionPool(host='drive.google.com', port=443): Max retries exceeded with url

Solution:

To resolve this issue, you can disable SSL certificate verification by using the --no-check-certificate option with the gdown command. Here’s an example:

gdown --no-check-certificate <file_url>

By adding the --no-check-certificate option, you bypass the SSL certificate verification and allow the download to proceed without errors.

Problem 2: Download Quota Exceeded Error

Another common problem with gdown is encountering a “Download quota exceeded” error. This error typically occurs when the file you’re trying to download has exceeded the download quota limit set by the file owner or Google Drive. Here’s an example of the error message:

Permission denied: https://drive.google.com/uc?id=<file_id>
Maybe you need to change permission over 'Anyone with the link'?

Solution:

To resolve the “Download quota exceeded” error, you can try making a copy of the file to your own Google Drive account and then download it using the gdown command. Follow these steps:

1. Open the file link in your browser and click on “Make a copy.”
2. Open the copied file in your Google Drive account.
3. Get the ID of the copied file from the URL in your browser.
4. Use the gdown command with the copied file ID to download the file:

gdown https://drive.google.com/uc?id=<copied_file_id>

By making a copy of the file and downloading it from your own Google Drive account, you should be able to bypass the download quota restriction.

Problem 3: Unsupported URL Error

The gdown command may throw an “Unsupported URL” error when the provided URL is not supported or recognized. This can happen if you’re using a non-standard URL format or a URL that is not compatible with gdown. Here’s an example of the error message:

Unsupported URL: <file_url>

Solution:

Ensure that the URL you’re providing to the gdown command is a valid and supported URL. Typically, gdown supports direct download URLs from Google Drive, such as those starting with https://drive.google.com/uc?id=. If you’re using a different URL format or from a different file hosting service, consider using alternative methods or tools specific to that service to download the file.

By addressing these common problems and following the provided solutions, you can overcome issues related to SSL certificate verification, download quota limitations, and unsupported URLs when using the gdown command.

A brief introduction to gdown

gdown is a command-line tool designed to simplify the downloading of files from Google Drive. It is particularly useful when working with large files hosted on Google Drive, allowing users to easily retrieve files by specifying the file’s unique identifier or URL. gdown simplifies the process by handling authentication and providing a streamlined interface for downloading files. It supports various file formats, including zip files, images, videos, and documents.

Under the hood, gdown utilizes the Google Drive API to interact with the user’s Google Drive account. It retrieves the file metadata, handles authentication using OAuth2, and initiates the download process. gdown is implemented in Python and can be installed via pip. It provides a straightforward command-line interface, making it accessible and convenient for users to incorporate into their scripts or workflows. With its simplicity and efficiency, gdown is a popular choice for downloading files from Google Drive programmatically.

Overall, gdown is a versatile tool that simplifies the process of downloading files from Google Drive. It streamlines the authentication and download process, allowing users to easily retrieve files by specifying the file’s unique identifier or URL. Whether it’s downloading large datasets, media files, or documents, gdown provides a reliable and efficient solution for accessing and retrieving files hosted on Google Drive.

Most popular use cases for gdown

1. Downloading Files from Google Drive: gdown is primarily used for downloading files from Google Drive. It provides a simple and convenient command-line interface that allows users to specify the file’s unique identifier or URL to initiate the download. Here is an example of using gdown to download a file using its unique identifier:

gdown https://drive.google.com/uc?id=your_file_id

2. Streamlining File Retrieval: gdown streamlines the process of retrieving files from Google Drive by handling authentication and providing an intuitive interface. It leverages the Google Drive API to retrieve file metadata, authenticate the user via OAuth2, and initiate the download process. This simplifies the task of accessing files hosted on Google Drive programmatically.
3. Supporting Various File Formats: gdown supports a wide range of file formats hosted on Google Drive, including zip files, images, videos, and documents. It provides a flexible solution for downloading files of different types and sizes. Users can rely on gdown to easily download large datasets, media files, or any other files stored on Google Drive.

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The previous maintainers of the package are transferring ownership due to personal reasons, and a new maintainer is taking over. The package has undergone significant changes and improvements, including a rewrite in TypeScript, enhanced test coverage, and the introduction of new features. However, there are still some missing features and changes to the configuration options.

New Features:

• Rewritten in TypeScript with improved test coverage.
• Support for the “Rule” keyword.
• Automatic filtering of specs without matching scenarios.
• Automatic inclusion of screenshots in JSON reports.
• Ability to add other attachments to the report.
• JSON reports are now generated as a single file without the need for manual merging.
• Package name has been changed to “@badeball/cypress-cucumber-preprocessor”.
• Deprecated methods “And(..)” and “But(..)” have been replaced.

Missing Features:

• Bundled feature files have been deprioritized.
• Changes to configuration options with no distinction between “global” and “non-global” steps.

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Problem solution for: Upgrade guide from `TheBrainFamily/cypress-cucumber-preprocessor`

To address the ownership transfer and the related changes in the package, here are the recommended steps to solve the problem:

1. Complete the Transfer: Ensure that the ownership transfer process is smoothly completed between the previous maintainers and the new maintainer. This may involve necessary administrative tasks and coordination.
2. Test and Verify: Thoroughly test the re-implemented package and its new features to identify any potential issues or bugs. Pay special attention to areas where test coverage was previously lacking. Use automated testing frameworks and tools to validate the functionality and compatibility of the package.
3. Address Missing Features: Evaluate the missing features, such as bundled feature files, and determine their importance and feasibility. If deemed necessary, work on implementing these features, considering the associated maintenance cost and performance implications.
4. Communicate with Users: Engage with the user community by actively seeking feedback and addressing their concerns. Encourage users to report any issues or questions they encounter with the package. Respond promptly, provide support, and resolve any reported issues to ensure a positive user experience.
5. Maintain Documentation: Update the package documentation to reflect the changes, new features, and configuration options. Ensure that the documentation is comprehensive, clear, and accessible to assist users in understanding and utilizing the package effectively.
6. Collaborate with the Community: Foster collaboration and engagement with the user community and other contributors. Encourage discussions, share knowledge, and address community concerns and suggestions. This collaboration can lead to further improvements and help maintain the package’s quality and longevity.

By following these steps, the new maintainer can successfully address the ownership transfer, ensure the package’s stability, and provide ongoing support and improvements to meet the needs of the user community.

Problem 1: Step Definitions Not Found

One common issue with cypress-cucumber-preprocessor is the inability to find step definitions during test execution. This can occur when the specified step definitions are not correctly configured or when there are discrepancies between the defined step patterns and the actual step definitions. The following error message may be encountered:

Error: Step definition not found for step: "Given I am on the login page"

Solution:

To resolve this issue, ensure that the step definitions are properly configured and located in the expected directories. Verify that the step patterns defined in the feature files match the step definitions exactly. Here’s an example configuration demonstrating the proper setup:

{
  "name": "my project",
  "dependencies": {},
  "devDependencies": {},
  "cypress-cucumber-preprocessor": {
    "stepDefinitions": "cypress/support/step_definitions/**/*.js"
  }
}

Make sure to adjust the "stepDefinitions" path according to your project’s directory structure.

Problem 2: Inconsistent Test Results

Another problem that can occur with cypress-cucumber-preprocessor is inconsistent test results. Tests may pass or fail inconsistently, even when the application behavior remains the same. This can lead to confusion and difficulty in identifying the root cause of failures.

Solution:

To address this issue, it is crucial to ensure that the tests and the application environment are set up consistently. Consider the following factors:

1. Test Environment: Make sure the test environment is properly configured, including any necessary dependencies, fixtures, or test data.
2. Test Isolation: Ensure that tests are isolated from one another to avoid interference or shared state. Use appropriate mechanisms, such as beforeEach and afterEach hooks, to set up and clean up the test environment.
3. Test Stability: Verify that the application under test is stable and reliable. Monitor for any external factors that may introduce variability in test results, such as network connectivity issues or server timeouts.

Problem 3: Performance Degradation

Cypress tests powered by cypress-cucumber-preprocessor may experience performance degradation, especially when dealing with large feature files or complex scenarios. Tests may become slow and impact the overall test execution time.

Solution:

To improve performance, consider the following strategies:

1. Test Optimization: Review the feature files and step definitions to identify any bottlenecks or areas where optimizations can be applied. Refactor and simplify the steps, eliminate unnecessary waits or delays, and use efficient selectors and assertions.
2. Test Parallelization: If your test suite is extensive, consider running tests in parallel to distribute the workload across multiple machines or processes. Cypress provides parallelization capabilities that can significantly reduce execution time.
3. Test Data Management: Efficiently manage test data by leveraging techniques such as test data factories, data caching, or database optimizations. This can help reduce the setup time and improve overall test performance.

A brief introduction to cypress-cucumber-preprocessor

Cypress-cucumber-preprocessor is a powerful testing tool that integrates Cypress, a popular end-to-end testing framework, with Cucumber, a behavior-driven development (BDD) tool. It allows developers and testers to write and execute feature files in a human-readable format using the Gherkin syntax, along with corresponding step definitions. Cypress-cucumber-preprocessor enables the execution of Cucumber scenarios as Cypress tests, providing a seamless and expressive way to perform BDD-style testing.

The tool enhances the capabilities of Cypress by enabling the use of Given-When-Then steps and the organization of tests into feature files. It simplifies the process of writing and maintaining test scenarios by providing a structured approach that promotes collaboration between technical and non-technical stakeholders. Cypress-cucumber-preprocessor leverages the power of Cypress, offering features such as powerful selectors, intelligent assertions, and easy-to-use test runners, while maintaining the natural language readability and clarity provided by Cucumber’s Gherkin syntax.

By combining the flexibility and expressiveness of Cucumber with the robustness and simplicity of Cypress, cypress-cucumber-preprocessor empowers teams to create comprehensive and maintainable end-to-end test suites. It facilitates the adoption of behavior-driven development practices and encourages clear communication and collaboration among team members. With its seamless integration and extensive capabilities, cypress-cucumber-preprocessor is a valuable tool for implementing BDD testing in Cypress-based projects.

Most popular use cases for cypress-cucumber-preprocessor

1. Behavior-driven Development (BDD) Testing: Cypress-cucumber-preprocessor enables the use of Cucumber’s Gherkin syntax for writing feature files and corresponding step definitions. This allows teams to adopt a BDD approach to testing, where test scenarios are written in a human-readable format that promotes collaboration and clarity. Here’s an example of a feature file written in Gherkin syntax:

Feature: Login Functionality
  As a user
  I want to login to my account
  So that I can access the protected features

  Scenario: Successful login
    Given I am on the login page
    When I enter my valid credentials
    And I click the login button
    Then I should be redirected to the dashboard
    And I should see a welcome message

2. Integration with Cypress: Cypress-cucumber-preprocessor seamlessly integrates with Cypress, a powerful end-to-end testing framework. It leverages Cypress’s features such as powerful selectors, intelligent assertions, and easy-to-use test runners, providing a solid foundation for executing BDD-style tests. Test scenarios written using the Gherkin syntax are transformed into Cypress tests, allowing teams to take advantage of Cypress’s capabilities while maintaining the readability and clarity of the original feature files.
3. Collaboration and Maintainability: By using cypress-cucumber-preprocessor, teams can enhance collaboration between technical and non-technical stakeholders. The clear and descriptive nature of Gherkin scenarios promotes better communication and understanding of the expected behavior of the application. Furthermore, the separation of feature files and step definitions allows for easier maintenance and reusability of test code. Teams can work together to write and maintain feature files, while developers can implement the corresponding step definitions in Cypress, resulting in a maintainable and scalable test suite.

The post Upgrade guide from `TheBrainFamily/cypress-cucumber-preprocessor` appeared first on Lightrun.

The issue at hand is more related to the Conda environment rather than the specific atac-seq-pipeline. When executing the install_conda_env.sh script, I encounter a significant delay during the “Solving environment” step, which can persist for several hours. The problem can be summarized as follows:

=== Installing pipeline's Conda environments ===
Collecting package metadata (current_repodata.json): ...working... done
Solving environment: ...working... failed with repodata from current_repodata.json, will retry with next repodata source.
Collecting package metadata (repodata.json): ...working... done
Solving environment: ...working...
(after ~6 hours the installation is successful)

To address this issue, several attempted solutions have been explored:

1. Adjusting Channel Priority: Different channel priority settings, such as strict, flexible, and false, have been tested. However, setting the priority to “strict” often results in package conflicts, while the “flexible” or “false” options take a considerable amount of time to resolve.
2. Modifying Package Version Specifications: Some strict version specifications in the requirements.txt file have been relaxed by opting for newer versions if available. However, these changes have not shown a noticeable impact on the installation speed.
3. Removing the “defaults” Conda Channel: As suggested by online sources, the “defaults” Conda channel has been removed from the installation command:

conda create -n ${CONDA_ENV_PY3} --file ${REQ_TXT_PY3} -y -c defaults -c r -c bioconda -c conda-forge

It has been reported that the “defaults” channel can potentially cause issues. Despite this adjustment, the installation process still encounters significant delays.

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Problem solution for: conda environment installation takes many hours

To address the issue of extended installation time and the “Solving environment” step delay when running the install_conda_env.sh script, there are a few potential solutions to consider:

1. Update Conda: Ensure that you are using the latest version of Conda. Check if there are any updates available and upgrade Conda to the latest stable release. This can be done using the following command:

conda update conda

2. Use Conda Environments: Instead of directly installing packages into the base environment, create a separate Conda environment specifically for the atac-seq-pipeline. This helps isolate dependencies and reduces the likelihood of package conflicts. Create a new environment with the following command:

conda create -n atac-seq-env

Activate the new environment before running the installation script:

conda activate atac-seq-env

Then proceed with the installation process.

3. Optimize Channel Order: Adjusting the order of the channels in the conda create command can sometimes improve installation speed. Experiment with different channel orders to prioritize the channels that are more likely to provide the required packages. For example:

conda create -n atac-seq-env --file requirements.txt -y -c r -c bioconda -c conda-forge -c defaults

By placing the channels that are known to contain the necessary packages earlier in the command, Conda will search them first, potentially reducing the time spent searching for packages.

Implementing these suggestions may help alleviate the extended installation time and solve the “Solving environment” step delay. However, if the problem persists, it may be beneficial to seek further assistance from the Conda community or the atac-seq-pipeline developers to explore additional troubleshooting steps.

Problem 1: Dependency Conflict One common problem with the atac-seq-pipeline is encountering dependency conflicts during installation or execution. This can occur when there are conflicting package versions required by different components of the pipeline. These conflicts can lead to installation failures or runtime errors.

Solution: To resolve dependency conflicts, it is recommended to create a separate Conda environment for the atac-seq-pipeline and carefully manage the package versions. First, create a new environment:

conda create -n atac-seq-env

Activate the new environment:

conda activate atac-seq-env

Then, install the required packages into the environment using the provided specifications or requirements file:

conda install -c bioconda atac-seq-pipeline

By isolating the pipeline in its own environment, you can ensure that the required dependencies are installed without conflicting with other packages in your system.

Problem 2: Execution Errors Another issue that can arise with the atac-seq-pipeline is encountering errors during execution. These errors may be due to various reasons such as incorrect input file formats, missing or misconfigured parameters, or issues with the underlying tools used by the pipeline.

Solution: To troubleshoot execution errors, carefully review the pipeline’s documentation and ensure that you are providing the correct input files and parameters. Double-check that all required dependencies and tools are properly installed and accessible. Additionally, check for any specific error messages or log files generated by the pipeline and use them as clues to identify and address the root cause of the errors.

Problem 3: Performance and Efficiency The atac-seq-pipeline may exhibit performance and efficiency issues, especially when processing large datasets. This can result in long processing times, high memory consumption, or suboptimal resource utilization.

Solution: To improve performance, consider optimizing the pipeline configuration and adjusting the parameters based on your specific dataset and hardware resources. For example, you can adjust the number of threads or processes used by certain steps of the pipeline to make better use of parallel processing capabilities. Additionally, ensure that you have allocated enough memory resources to accommodate the size of your dataset. Experimenting with different configurations and profiling the pipeline’s performance can help identify bottlenecks and optimize resource utilization.

By addressing these common problems and following the suggested solutions, you can enhance the installation process, troubleshoot execution errors, and improve the performance and efficiency of the atac-seq-pipeline for your specific use case.

A brief introduction to atac-seq-pipeline

The atac-seq-pipeline is a bioinformatics tool specifically designed for the analysis of ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing) data. It provides a comprehensive set of tools and workflows for processing and analyzing ATAC-seq datasets, allowing researchers to gain insights into chromatin accessibility and regulatory elements in a genome-wide manner.

The pipeline follows a standardized analysis workflow that includes key steps such as read alignment, peak calling, quality control, and downstream analysis. It incorporates widely used bioinformatics tools and algorithms, such as Bowtie, MACS2, and BEDTools, to perform these tasks. The atac-seq-pipeline is implemented as a collection of scripts and utilizes the Conda package manager to handle dependencies and ensure reproducibility of the analysis environment.

By leveraging the atac-seq-pipeline, researchers can automate and streamline their ATAC-seq data analysis workflows, enabling them to efficiently process large-scale datasets and generate meaningful results. It provides a standardized and validated approach for handling the various stages of ATAC-seq data analysis, reducing the burden of manually integrating multiple tools and facilitating the reproducibility of analysis pipelines across different experiments and researchers.

Most popular use cases for atac-seq-pipeline

1. Processing ATAC-seq Data: The atac-seq-pipeline is specifically designed to handle the processing of ATAC-seq data, starting from raw sequencing reads to downstream analysis. It provides functionalities for read alignment, duplicate removal, quality control, and peak calling. Researchers can utilize the pipeline to preprocess and prepare their ATAC-seq data for further analysis.

# Example command for running read alignment using the atac-seq-pipeline
align_reads --input reads.fastq --genome hg19 --output aligned_reads.bam

2. Identifying Differential Accessibility: One of the key applications of ATAC-seq data is to identify regions of differential chromatin accessibility between different biological conditions. The atac-seq-pipeline offers tools for performing differential accessibility analysis, allowing researchers to compare the chromatin accessibility profiles of different samples or experimental conditions.

# Example command for performing differential accessibility analysis using the atac-seq-pipeline
differential_accessibility --condition1 sample1.bam --condition2 sample2.bam --output diff_accessibility.bed

3. Annotation and Visualization: The atac-seq-pipeline enables researchers to annotate and visualize the identified peaks and regulatory elements in the ATAC-seq data. It provides functionalities to annotate peaks with genomic features, such as gene promoters, enhancers, and transcription factor binding sites. Additionally, researchers can generate plots and visualizations to gain insights into the distribution and patterns of chromatin accessibility across the genome.

# Example command for annotating peaks using the atac-seq-pipeline
annotate_peaks --input peaks.bed --genome hg19 --output annotated_peaks.bed

# Example command for generating a plot of chromatin accessibility profile using the atac-seq-pipeline
plot_accessibility --input accessibility.bw --region chr1:1000-2000 --output accessibility_plot.png

These are just a few examples of the diverse range of analyses that can be performed using the atac-seq-pipeline. It provides researchers with a comprehensive toolkit for exploring and interpreting ATAC-seq data, enabling them to uncover valuable insights into chromatin accessibility and regulatory mechanisms.

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Problem Description:

When using CSScritics, an error occurs stating, “Blocked script execution in ‘http://solar-druid.codio.io/tests/csscritic.html‘ because the document’s frame is sandboxed and the ‘allow-scripts’ permission is not set.” The error message points to the file “rasterizeHTML.allinone.js” and the functions “calculateDocumentContentSize” and “drawDocumentAsSvg.” It appears that the error is related to an <iframe> element with the sandbox attribute, which is attempting to run JavaScript without the necessary permission.

Resolution Explanation:

The error message indicates that the <iframe> element in question is using the sandbox attribute, which restricts the execution of scripts unless explicitly allowed with the “allow-scripts” permission. In the rasterizeHTML source code, the function “createHiddenSandboxedIFrame()” is responsible for creating the sandboxed frame, which is used by “calculateDocumentContentSize()” to copy the contents of the document and measure their size. The presence of <script> tags within the document causes the error, as scripts are generally disallowed within sandboxed frames.

Reproducing the Bug:

The bug was observed on Chromium 45.0.2454.101 running on Ubuntu 15.04 (64-bit) when accessing “./test/csscritic.html.” The tested page is “./index.html,” and under normal circumstances, the expected output should resemble “2015-12-29_mathador_ui_home.” It is worth noting that this bug report includes a greeting message, “Hi Christopher, long time not seen!”

Overall, this problem with the CSScritics tool involves a sandboxed <iframe> and the lack of the “allow-scripts” permission, resulting in blocked script execution. Understanding the cause of the error allows for targeted troubleshooting and potentially modifying the sandbox settings or script usage to resolve the issue.

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Problem solution for: “…document’s frame is sandboxed and the ‘allow-scripts’ permission is not set”

To solve the problem of blocked script execution in the sandboxed frame of CSScritics, you need to ensure that the necessary permissions are set for script execution within the <iframe>. Specifically, the “allow-scripts” permission needs to be included in the sandbox attribute of the <iframe> element.

Here’s an example of how to modify the sandbox attribute to include the “allow-scripts” permission:

<iframe src="http://solar-druid.codio.io/tests/csscritic.html" sandbox="allow-scripts"></iframe>

By adding “allow-scripts” to the sandbox attribute, you explicitly grant permission for scripts to run within the <iframe>. This should resolve the issue of blocked script execution in the sandboxed frame.

It’s important to note that modifying the sandbox settings should be done with caution, as it can have security implications. Make sure to consider the potential risks and only enable permissions that are necessary for your specific use case.

1. Issue: Blocked script execution in a sandboxed frame Problem Description: One common problem with rasterizeHTML.js is the blocked script execution in a sandboxed frame. This occurs when an <iframe> element with the sandbox attribute is attempting to run JavaScript without the “allow-scripts” permission set. As a result, the script execution is blocked, and an error message is displayed. This issue can prevent certain functionalities or operations from working as expected.

Solution: To address this problem, you need to modify the sandbox attribute of the <iframe> element to include the “allow-scripts” permission. By explicitly granting script execution permission, the JavaScript code within the sandboxed frame will be allowed to run. Here’s an example of how to modify the sandbox attribute:

<iframe src="http://example.com" sandbox="allow-scripts"></iframe>

By including “allow-scripts” in the sandbox attribute, you enable the execution of scripts within the sandboxed frame, resolving the blocked script execution issue.

2. Issue: Performance and Rendering Efficiency Problem Description: Another common challenge with rasterizeHTML.js is related to performance and rendering efficiency. When rendering complex or large HTML documents, the library may encounter performance issues, resulting in slower rendering times and increased memory usage. This can be problematic, particularly when dealing with extensive or dynamically generated HTML content.

Solution: To optimize the performance and rendering efficiency of rasterizeHTML.js, consider the following strategies:

• Simplify and optimize the HTML structure: If possible, simplify the HTML structure by removing unnecessary elements, reducing nested levels, and optimizing CSS selectors. This can help improve rendering performance.
• Implement caching mechanisms: Utilize caching mechanisms to store previously rendered HTML content and avoid unnecessary re-rendering. This can be achieved using browser caching or server-side caching techniques.
• Break large documents into smaller parts: If dealing with large HTML documents, consider breaking them into smaller parts and rendering them incrementally. This can help distribute the rendering workload and improve overall performance.

3. Issue: Cross-Origin Resource Sharing (CORS) Restrictions Problem Description: RasterizeHTML.js may encounter issues with Cross-Origin Resource Sharing (CORS) restrictions when attempting to render HTML content from different domains. CORS is a security mechanism implemented by browsers to restrict access to resources across different origins. If the HTML content being rendered by rasterizeHTML.js is hosted on a different domain, CORS restrictions can prevent the rendering process.

Solution: To overcome CORS restrictions, you have a few options:

• Configure CORS headers on the server: If you have control over the server hosting the HTML content, ensure that it includes the appropriate CORS headers to allow cross-origin requests. This typically involves setting the “Access-Control-Allow-Origin” header to specify the allowed domains.
• Proxy the HTML content: Instead of directly rendering HTML content from a different domain, you can set up a server-side proxy that fetches the content from the remote domain and serves it from your own domain. This way, the content is considered same-origin, and CORS restrictions are bypassed.
• Embed the HTML content within the same domain: If feasible, consider hosting the HTML content within the same domain as the rasterizeHTML.js script. This ensures that the content is considered same-origin, eliminating CORS restrictions.

A brief introduction to rasterizeHTML.js

RasterizeHTML.js is a powerful JavaScript library that enables the rendering of HTML content into various formats, such as images or PDF files. It provides a convenient solution for generating static snapshots or representations of HTML documents programmatically. By utilizing the underlying browser rendering engine, rasterizeHTML.js accurately captures the visual appearance of the HTML content, including the styling, layout, and graphical elements.

One of the key features of rasterizeHTML.js is its ability to handle complex HTML structures and dynamically generated content. The library supports rendering of HTML documents that contain CSS styles, JavaScript interactivity, and embedded resources like images or fonts. It ensures fidelity in the rendering process, allowing developers to create pixel-perfect representations of HTML content. With rasterizeHTML.js, developers can leverage the power of browser rendering capabilities in server-side applications or headless environments, enabling tasks such as generating PDF reports, capturing website screenshots, or producing static images of web pages.

Furthermore, rasterizeHTML.js provides a flexible and customizable API for controlling the rendering process. Developers can specify options such as the desired output format, image dimensions, scaling, or background color. The library also supports event handling, allowing the execution of custom JavaScript code before or after rendering, enabling further customization and integration with other workflows. With its comprehensive functionality and ease of use, rasterizeHTML.js empowers developers to seamlessly incorporate HTML rendering capabilities into their applications, enhancing the versatility and visual representation of their content.

Most popular use cases for rasterizeHTML.js

1. Generating Static Images: RasterizeHTML.js can be used to generate static images of HTML content, allowing developers to capture the visual representation of web pages or specific HTML elements. By specifying the desired dimensions and format, developers can utilize the library to create image snapshots of HTML documents programmatically. Here’s an example code snippet demonstrating how to generate an image using rasterizeHTML.js:

const rasterizeHTML = require('rasterizehtml');

const htmlContent = '<div><h1>Hello, world!</h1><p>This is a sample HTML content.</p></div>';
const imageOptions = {
  width: 800,
  height: 600,
  format: 'png',
};

rasterizeHTML.drawHTML(htmlContent, imageOptions)
  .then((imageData) => {
    // Use the generated image data
    console.log('Image data:', imageData);
  })
  .catch((error) => {
    // Handle any errors
    console.error('Error generating image:', error);
  });

2. Creating PDF Documents: RasterizeHTML.js enables the generation of PDF documents from HTML content. It can convert HTML elements or entire web pages into PDF format, preserving the layout, styling, and graphical elements. This functionality is useful for generating printable reports, exporting web content as PDFs, or creating document snapshots. By specifying PDF-specific options, developers can control aspects such as page size, margins, and orientation. Here’s an example code snippet illustrating how to generate a PDF using rasterizeHTML.js:

const rasterizeHTML = require('rasterizehtml');

const htmlContent = '<div><h1>Hello, world!</h1><p>This is a sample HTML content.</p></div>';
const pdfOptions = {
  format: 'Letter',
  margin: '1cm',
};

rasterizeHTML.drawHTML(htmlContent, pdfOptions, 'output.pdf')
  .then(() => {
    // PDF generation completed
    console.log('PDF generated successfully.');
  })
  .catch((error) => {
    // Handle any errors
    console.error('Error generating PDF:', error);
  });

3. Headless Browser Automation: RasterizeHTML.js can be utilized for headless browser automation tasks. By leveraging its HTML rendering capabilities, developers can programmatically interact with web pages, extract information, perform DOM manipulations, and capture rendered content. This enables various use cases, such as web scraping, web testing, or generating dynamic content snapshots. With its ability to execute JavaScript and handle complex HTML structures, rasterizeHTML.js provides a powerful tool for simulating browser behavior in headless environments.

The post “…document’s frame is sandboxed and the ‘allow-scripts’ permission is not set” appeared first on Lightrun.

When using json-server to mock a login API, there is a specific scenario where posting a request to the “/login” endpoint with a certain body causes the deletion of the resource under the “login” route in the “db.json” file.

Here’s an example of the “db.json” file containing the initial login resource:

{
  "login": {
    "username": "my name",
    "role": ["admin"]
  }
}

To simulate a login request, a POST request is made to the “/login” endpoint with the following body:

{
  "username": "user_name",
  "password": "123456"
}

However, instead of authenticating the user and returning the expected response, this request triggers the deletion of the resource under the “login” route in the “db.json” file. This behavior can be unexpected and may cause data inconsistencies.

Getting a sense of what’s actually happening inside a live application is a frustrating experience, one that relies mostly on querying and observing whatever logs were written during development.
Lightrun is a Developer Observability Platform, allowing developers to add telemetry to live applications in real-time, on-demand, and right from the IDE.

• Instantly add logs to, set metrics in, and take snapshots of live applications
• Insights delivered straight to your IDE or CLI
• Works where you do: dev, QA, staging, CI/CD, and production

Start for free today

Problem solution for: How to mock a api for login?

To resolve the issue of the resource being deleted when posting to the “/login” endpoint in json-server, you need to configure json-server to handle the login request appropriately and prevent the unintended deletion of data.

One possible solution is to define a custom route specifically for the login functionality. This can be achieved by creating a JavaScript file, let’s call it “loginRoute.js,” where you define the route and its corresponding logic. Here’s an example:

// loginRoute.js

module.exports = (req, res, next) => {
  if (req.method === 'POST' && req.url === '/login') {
    // Handle the login request here
    const { username, password } = req.body;

    // Perform authentication logic and return the desired response
    // You can retrieve the existing login resource from the db.json file if needed

    // Example response
    const response = {
      success: true,
      message: 'Login successful',
      data: {
        username,
        role: ['admin']
      }
    };

    res.json(response);
  } else {
    // Pass the request to the next middleware if it doesn't match the login route
    next();
  }
};

Next, you need to modify the “server.js” file (or the file where you start json-server) to include this custom route. Here’s an example of how you can configure json-server to use the “loginRoute.js” file:

// server.js

const jsonServer = require('json-server');
const loginRoute = require('./loginRoute');

const server = jsonServer.create();
const router = jsonServer.router('db.json');
const middlewares = jsonServer.defaults();

server.use(middlewares);
server.use(jsonServer.bodyParser);

// Add the login route
server.use(loginRoute);

// Use the default router for other routes
server.use(router);

const PORT = 3000;
server.listen(PORT, () => {
  console.log(`JSON Server is running on port ${PORT}`);
});

With this setup, the login request will be handled separately by the custom route, ensuring that the data in the “login” resource is not unintentionally deleted. Other requests will continue to be handled by the default json-server router.

Remember to adjust the file paths and logic in the example code to match your project’s structure and specific requirements.

1. Problem 1: Handling Relationships and Complex Data Structures

   One common challenge when using json-server is handling relationships and complex data structures. By default, json-server provides a simple RESTful API that treats each JSON file as a standalone resource. However, it lacks built-in support for defining relationships between resources or handling nested data structures.

   To address this problem, you can leverage json-server’s ability to define custom routes and middleware to implement custom logic for handling relationships. Here’s an example of how you can define a custom route to handle a nested resource:

// server.js

const jsonServer = require('json-server');
const server = jsonServer.create();
const router = jsonServer.router('db.json');
const middlewares = jsonServer.defaults();

server.use(middlewares);
server.use(jsonServer.bodyParser);

// Custom route to handle nested resource
server.get('/posts/:postId/comments', (req, res) => {
  const { postId } = req.params;
  const comments = router.db.get('comments').filter({ postId }).value();
  res.json(comments);
});

server.use(router);

const PORT = 3000;
server.listen(PORT, () => {
  console.log(`JSON Server is running on port ${PORT}`);
});

In this example, we define a custom route to handle the retrieval of comments for a specific post. By extending json-server with custom routes and middleware, you can handle complex data structures and relationships more effectively.

Problem 2: Authentication and Authorization

Another common problem with json-server is the lack of built-in authentication and authorization mechanisms. Json-server treats all requests as authorized and does not provide a way to secure the API endpoints.

To address this issue, you can integrate json-server with other libraries or implement custom middleware to handle authentication and authorization. Here’s an example of how you can use the express-jwt library to secure your json-server API:

// server.js

const jsonServer = require('json-server');
const jwt = require('express-jwt');
const server = jsonServer.create();
const router = jsonServer.router('db.json');
const middlewares = jsonServer.defaults();

server.use(middlewares);
server.use(jsonServer.bodyParser);

// Protect the API with JWT authentication
server.use(
  jwt({ secret: 'your-secret-key', algorithms: ['HS256'] }).unless({ path: ['/login'] })
);

// Custom login route
server.post('/login', (req, res) => {
  // Handle authentication logic and generate JWT token
  // Return the token in the response
});

server.use(router);

const PORT = 3000;
server.listen(PORT, () => {
  console.log(`JSON Server is running on port ${PORT}`);
});

In this example, we use the express-jwt library to authenticate and authorize requests based on JSON Web Tokens (JWT). The jwt middleware is applied to all routes except the “/login” route, ensuring that only authenticated requests can access the protected resources.

Problem 3: Lack of Data Persistence

By default, json-server stores data in memory, which means that any changes made to the data are lost once the server is restarted. This can be problematic if you need to persist data across server restarts or share data between multiple instances of json-server.

To overcome this limitation, you can use a data persistence solution such as a database or a file system to store the data. One popular approach is to integrate json-server with a database using a library like lowdb or sequelize. Here’s an example of how you can use lowdb to persist data to a JSON file:

// server.js

const jsonServer = require('json-server');
const low = require('lowdb');
const FileSync = require('lowdb/adapters/FileSync');

const adapter = new FileSync('db.json');
const db = low(adapter);

const server = jsonServer.create();
const router = jsonServer.router(db);
const middlewares = jsonServer.defaults();

server.use(middlewares);
server.use(jsonServer.bodyParser);
server.use(router);

const PORT = 3000;
server.listen(PORT, () => {
  console.log(`JSON Server is running on port ${PORT}`);
});

In this example, we use the lowdb library to persist data to a JSON file. The data is loaded from the “db.json” file into the db object, which is then passed to the json-server router. Any changes made to the data will be persisted to the file, ensuring data persistence across server restarts.

A brief introduction to json-server

Json-server is a popular tool used for quickly creating RESTful APIs based on a JSON file. It is built on top of Express.js and provides a simple way to mock server responses and simulate API behavior without the need for a backend server. Json-server allows developers to define routes, endpoints, and data directly in a JSON file, making it easy to create a fully functional API with minimal setup.

With json-server, you can define various HTTP methods such as GET, POST, PUT, DELETE, etc., and the corresponding responses in the JSON file. It supports basic CRUD operations and provides features like filtering, sorting, and pagination out of the box. Json-server also supports complex data structures, allowing you to define relationships between resources and handle nested data.

Here’s an example of how a json-server configuration file might look:

{
  "users": [
    { "id": 1, "name": "John Doe", "email": "john.doe@example.com" },
    { "id": 2, "name": "Jane Smith", "email": "jane.smith@example.com" }
  ],
  "posts": [
    { "id": 1, "title": "First Post", "content": "Lorem ipsum dolor sit amet." },
    { "id": 2, "title": "Second Post", "content": "Praesent volutpat malesuada odio." }
  ]
}

In this example, we have two resources: “users” and “posts”, each represented as an array of objects. By running the json-server command and specifying the JSON file as the data source, the API endpoints for these resources are automatically generated. For instance, you can access the users’ data via the “/users” endpoint and perform operations like GET, POST, PUT, and DELETE on the data.

Overall, json-server simplifies the process of mocking APIs and allows developers to focus on frontend development without having to set up and maintain a full-fledged backend server. It is widely used for prototyping, testing, and frontend development, providing a lightweight and efficient solution for simulating RESTful APIs.

Most popular use cases for json-server

1. Rapid API prototyping: Json-server is an excellent tool for quickly creating mock APIs during the initial stages of development. By defining routes and data in a JSON file, developers can easily simulate API responses without the need for a fully implemented backend. This allows frontend developers to start building and testing their applications without waiting for the backend development to be completed.

Here’s an example of how json-server can be used to create a mock API for a blog:

{
  "posts": [
    { "id": 1, "title": "First Post", "content": "Lorem ipsum dolor sit amet." },
    { "id": 2, "title": "Second Post", "content": "Praesent volutpat malesuada odio." }
  ],
  "comments": [
    { "id": 1, "postId": 1, "text": "Great post!" },
    { "id": 2, "postId": 1, "text": "I enjoyed reading this." },
    { "id": 3, "postId": 2, "text": "Nice article!" }
  ]
}

2. Frontend development and testing: Json-server is widely used in frontend development workflows for testing and prototyping frontend applications. It allows frontend developers to interact with API endpoints, test different scenarios, and validate their frontend components without relying on a live backend server. This speeds up the development process and enables efficient iteration and debugging.

Here’s an example of how json-server can be used to interact with a mock API endpoint:

# Start json-server with the JSON file as the data source
json-server --watch db.json

# Access the API endpoint for posts
GET http://localhost:3000/posts

# Add a new post
POST http://localhost:3000/posts
Body:
{
  "title": "New Post",
  "content": "Lorem ipsum dolor sit amet."
}

# Update a post
PUT http://localhost:3000/posts/1
Body:
{
  "title": "Updated Post",
  "content": "New content"
}

# Delete a post
DELETE http://localhost:3000/posts/1

3. Educational purposes and learning API concepts: Json-server can be a valuable tool for learning about RESTful APIs and practicing API development concepts. It provides a hands-on experience of defining routes, handling HTTP methods, and manipulating data. Json-server’s simplicity and ease of use make it an accessible choice for beginners who want to explore API development without the complexity of setting up a full backend infrastructure. By experimenting with json-server, developers can gain a solid understanding of API fundamentals and best practices.

Overall, json-server serves as a versatile tool for creating mock APIs, facilitating frontend development and testing, and enabling learning opportunities in the realm of API development. Its simplicity, flexibility, and ability to work with JSON files make it a popular choice among developers for quickly simulating RESTful APIs.

The post How to mock a api for login? appeared first on Lightrun.

The encountered issue pertains to a type error in the given code. Although the exact nature of the error is unclear at the moment, assistance is sought to resolve this problem. The code snippet includes the definition of an interface named NPM, which describes the structure of an object containing information related to an NPM package. Additionally, an import statement is used to bring in the Response and Router types from the “farrow-http” module.

// Definition of the NPM interface
export interface NPM {
    name: string
    "dist-tag": {
        [tag: string]: string
    }
    maintainers: {
        name: string
        email: string
        avatar: string
    }[]
    time: {
        [version: string]: string
    }
    author: {
        name: string
        email: string
    }
    license: string
}

import { Response, Router } from "farrow-http"

// Creating a router instance
export const router = Router()

// Matching a specific path and query parameters
router
    .match({
        pathname: "/search",
        query: {
            search: String,
            limit: Number,
        },
    })
    .use(async request => {
        const { search, limit } = request.query
        // search
        const details = await getPackageDetail(search)

        return Response.json({
            code: 0,
            data

Upon execution of the code, an error is encountered with the following message: “Argument of type ‘{ code: number; data: NPM[]; }’ is not assignable to parameter of type ‘JsonType’. Type ‘{ code: number; data: NPM[]; }’ is not assignable to type ‘undefined’.” The accompanying image showcases the error message and the related code.

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Problem solution for: Type Question: Response.json get type error: is not assignable to type ‘undefined’.ts(2345)

To address the type error in the given code, the following steps can be taken:

1. Ensure that the Response.json method is properly configured to handle the response data. The error message suggests that the provided argument { code: number; data: NPM[]; } is not assignable to the expected type JsonType. Review the Response.json method implementation and verify that it can accept an object with properties code and data as expected.
2. Check if the type definition for JsonType is correctly imported and used in the code. It’s possible that there is a mismatch between the expected type and the actual usage. Verify the type definition of JsonType and ensure it aligns with the expected structure of the response object.
3. Validate that the getPackageDetail function returns a value that matches the expected type of details. The error might be originating from the data retrieved by this function. Ensure that the returned data adheres to the structure defined by the NPM interface.

By examining and adjusting these aspects of the code, the type error should be resolved, allowing for proper assignment of the response object to the JsonType parameter and eliminating the encountered issue.

1. Routing Configuration Issue: Problem Description: One common problem with Farrow is related to incorrect routing configuration. This can occur when routes are not properly defined or when the routing logic is not implemented correctly. It can result in unexpected behavior, such as requests not being handled or routed to the correct handlers.

Solution: To address this issue, it is important to review the routing configuration and ensure that routes are defined correctly using the appropriate methods and handlers. Here’s an example of how to define routes in Farrow:

import { Router, Request, Response } from "farrow-http";

const router = Router();

router.get("/users", async (request: Request) => {
  // Handle GET /users request
  // ...
  const users = await getUsers();
  return Response.json(users);
});

router.post("/users", async (request: Request) => {
  // Handle POST /users request
  // ...
  const newUser = await createUser(request.body);
  return Response.json(newUser);
});

// Other routes...

export default router;

By ensuring that the routes are properly defined and the corresponding handlers are implemented correctly, the routing configuration issue can be resolved.

2. Middleware Ordering Issue: Problem Description: Another common problem with Farrow is related to the ordering of middleware. Farrow uses a middleware-based architecture, and the order in which middleware functions are applied can impact the request flow and behavior. If the middleware is not ordered correctly, it can lead to unexpected results or cause certain middleware to be skipped.

Solution: To resolve this issue, it is important to carefully order the middleware functions in the middleware pipeline. Middleware functions are typically added to the pipeline using the use method. Here’s an example:

import { App } from "farrow-http";
import { loggerMiddleware, authMiddleware, corsMiddleware } from "./middlewares";

const app = new App();

app.use(loggerMiddleware);
app.use(authMiddleware);
app.use(corsMiddleware);

// Other middleware and routes...

app.listen(3000, () => {
  console.log("Server started on port 3000");
});

By correctly ordering the middleware functions in the pipeline, you can ensure that each middleware is executed in the desired sequence and that the request flow is handled as intended.

3. Error Handling and Middleware: Problem Description: Error handling can be a challenging aspect when using Farrow, especially when it comes to handling errors in middleware functions. If errors occur within a middleware function and are not properly handled, they can propagate and result in incomplete or incorrect responses being sent back to the client.

Solution: To effectively handle errors in middleware functions, it is important to use try-catch blocks or error handling middleware. Here’s an example of using a custom error handling middleware in Farrow:

import { App, Request, Response } from "farrow-http";

const app = new App();

// ...

// Custom error handling middleware
app.use(async (request: Request, next: () => Promise<Response>) => {
  try {
    // Execute the next middleware or route handler
    return await next();
  } catch (error) {
    // Handle the error and send an appropriate response
    console.error("Error occurred:", error);
    return Response.json({ error: "Internal Server Error" }, { status: 500 });
  }
});

// ...

app.listen(3000, () => {
  console.log("Server started on port 3000");
});

By implementing proper error handling middleware, you can catch and handle errors within middleware functions, ensuring that the appropriate response is sent back to the client and preventing unexpected behavior or incomplete responses.

These are three common problems encountered with Farrow and their corresponding solutions. By understanding and addressing these issues, developers can enhance their Farrow applications and ensure smooth and reliable functionality.

A brief introduction to farrow

Farrow is a minimalistic and efficient web framework for Node.js that focuses on simplicity and extensibility. Built with TypeScript, Farrow provides a robust foundation for building web applications and APIs. It adopts a middleware-based architecture, allowing developers to easily compose and customize the request-response flow. Farrow promotes a declarative and functional programming style, making it intuitive and easy to understand.

One of the key features of Farrow is its powerful routing system. With Farrow, developers can define routes using a simple and expressive syntax, making it effortless to handle HTTP requests and define the corresponding response logic. Farrow supports various HTTP methods such as GET, POST, PUT, DELETE, and more. It also provides convenient utilities for handling parameters, query strings, headers, and request bodies. The routing system in Farrow enables developers to create clean and organized code structures, improving maintainability and scalability of the application.

Another notable feature of Farrow is its middleware ecosystem. Middleware functions play a crucial role in the request handling process, allowing developers to add custom logic at various stages of the request-response cycle. Farrow provides a middleware pipeline that executes middleware functions in the order they are added, providing flexibility in defining the behavior of the application. The middleware system in Farrow enables common tasks such as authentication, logging, error handling, and request/response transformations. Additionally, Farrow allows developers to create and share reusable middleware packages, fostering a rich and vibrant ecosystem.

Most popular use cases for farrow

Building RESTful APIs: Farrow is well-suited for building RESTful APIs due to its flexible routing system and middleware architecture. Developers can define routes for different HTTP methods and handle request parameters, query strings, and headers with ease. Here’s an example of how Farrow can be used to define a simple API endpoint:

import { createApp, HttpHandler } from 'farrow'

const app = createApp()

app.get('/api/users/:id', (request, response) => {
  const userId = request.params.id
  // Retrieve user data from the database
  const user = getUser(userId)
  // Return the user data as the response
  response.json(user)
})

app.listen(3000, () => {
  console.log('Server is running on port 3000')
})

2. Microservices Architecture: Farrow’s lightweight and modular design makes it suitable for implementing microservices architectures. With Farrow, developers can create independent services that communicate with each other via HTTP or other protocols. Farrow’s middleware pipeline allows for easy integration of service-specific logic and cross-cutting concerns. Each microservice can have its own Farrow application, providing a cohesive and scalable architecture for complex systems.
3. Prototyping and Rapid Development: Farrow’s emphasis on simplicity and ease of use makes it a great choice for prototyping and rapid development. With Farrow, developers can quickly create functional web applications with minimal boilerplate. The intuitive syntax and declarative style of Farrow enable fast iteration and experimentation. Additionally, Farrow’s extensive middleware ecosystem and supportive community provide a wide range of pre-built middleware packages, accelerating development speed and reducing time to market.

The post Type Question: Response.json get type error: is not assignable to type ‘undefined’.ts(2345) appeared first on Lightrun.