react-safe-lazy

A simple and safe way to use React.lazy when you are iterating React app fast. It will catch the error and automatically retry to import or refresh the page when a lazy React component fails to load.

See this blog post for the motivation of this library and implementation details.

Installation

npm i react-safe-lazy

• Direct dependencies: 0.
• Peer dependency: react@^18.0.0.

Usage

Just replace React.lazy with safeLazy and you are good to go.

import { safeLazy } from 'react-safe-lazy';

const MyComponent = safeLazy(() => import('./MyComponent'));

Documentation

The default safeLazy function

The default safeLazy function have the following strategy:

• It will not retry calling the import function if it fails.
• It will reload the page (window.location.reload) once if the lazy component fails to load. If the lazy component fails to load again, the error will be thrown.

Customizing the safeLazy function

You can create a custom safeLazy function by calling the createSafeLazy function with a configuration object.

import { createSafeLazy } from 'react-safe-lazy';

const safeLazy = createSafeLazy({ /* configuration */ });
const MyComponent = safeLazy(() => import('./MyComponent'));

The configuration object has the following properties:

type SafeLazyConfigInit = {
  /**
   * The configuration for force-reloading components that fail to load. If set to `false`, the
   * component will not be force-reloaded.
   *
   * @default
   * { maxRetries: 1, storageKey: 'forceReloadedImportFunctions' }
   */
  forceReload?: false | Partial<ForceReloadConfig>;
  /**
   * The number of times to retry importing the component if it fails to load.
   *
   * @default 0
   */
  importRetries?: number;
};

type ForceReloadConfig = {
  /**
   * The maximum number of times to reload the page (using `window.location.reload`) if the
   * component fails to load.
   */
  maxRetries: number;
  /**
   * The key used to store the force-reloaded function information in the session storage.
   *
   * @default 'forceReloadedImportFunctions'
   */
  storageKey?: string;
};

For example, to retry importing the component 3 times and reload the page up to 2 times if the component fails to load, you can use the following configuration:

const safeLazy = createSafeLazy({
  importRetries: 3,
  forceReload: {
    maxRetries: 2,
  },
});

Note

In the above example, the safeLazy function will retry importing the component 3 times for each page load, which means that the import function will be called at most 4 * 3 = 12 times before giving up.

License

MIT