babel-plugin-dynamic-import-override

Babel plugin to override every dynamic import in application by attaching success and error handler.

Goals

To override all lazy-loaded chunks in an application from a single file, babel.config.js (or .babelrc), eliminating the need to manually override every chunk.

Installation

npm install -D babel-plugin-dynamic-import-override

yarn add -D babel-plugin-dynamic-import-override

Options

• errorHandler - error object is accesible in err.

• successHandler - result is accesible in res.

NOTE: successHandler and errorHandler should be wrapped as string. Dynamic Import that has failed/succeeded can be accessed via following variables: [Refer: example]

• importNode - Contains full code of dynamic import. Example: import('./Home.js')
• importName - Contains file name of dynamic import. Example: ./Home.js

Skip Overriding Dynamic Import

To skip overriding some dynamic imports, use following magic comment in the dynamic imports

/* skipImportOverride: true */

Usage

Via babel.config.js (Recommended)

babel.config.js

module.exports = function (api) {
  api.cache(true);

  const plugins = [
    ["babel-plugin-dynamic-import-override", {
      "successHandler": `console.log('inside success handler, perform success handling here, result is available in res');
        console.log(res);`,
      "errorHandler": `console.log('inside error handler, perform error handling here, error is available in err');
        console.log(err);`
    }]
  ];

  return {
    presets,
    plugins
  };
}

.babelrc

{
  "plugins": [
    ["babel-plugin-dynamic-import-override", {
      "successHandler": "console.log('inside success handler, perform success handling here, result is available in res', res);",
      "errorHandler": "console.log('inside error handler, perform error handling here, error is available in err', err);"
    }]
  ]
}

Example

Example 1:

import('./Home.js');

will be converted to,

Promise.resolve(import('./Home.js'))
.then(res => {
  // --- successhandler code will come here ----
  return res;
})
.catch(err => {
  // --- errorhandler code will come here ----
  throw err;
});

Any .catch and .then attached to dynamic import will stay as it is and will not be replaced.

import('./Home.js')
.then(data => console.log(data))
.catch(err => {throw err;});

will be converted to,

Promise.resolve(import('./Home.js')
.then(data => console.log(data)) // Original then handler
.then(res => {
  // --- successhandler code will come here ----
  return res;
})
.catch(err => {throw err;})) // Original catch handler
.catch(err => {
  // --- errorhandler code will come here ----
  throw err;
});

Example 2: Skip Overriding Dynamic Imports

To skip overriding following dynamic import,

import('./Home.js');

Change it to following,

import(/* skipImportOverride: true */ './Home.js');

Contributing

Contributions are welcomed! Read the Contributing Guide for more information.

Licensing

This project is licensed under the MIT License. See LICENSE for more information.