plasticine/inject-loader

๐Ÿ’‰๐Ÿ“ฆ A Webpack loader for injecting code into modules via their dependencies.

JavaScript

486

116 commits

updated Jun 20, 2026

See the code

README

ย 

๐Ÿ’‰๐Ÿ“ฆ

inject-loader

A Webpack loader for injecting code into modules via their dependencies

build status npm version npm downloads

Why

This is particularly useful for writing tests where mocking things inside your module-under-test is sometimes necessary before execution.

inject-loader was inspired by, and builds upon ideas introduced in jauco/webpack-injectable.

Usage

Documentation: Using loaders

Use the inject loader by adding the inject-loader! inline loader when you use require, this will return a function that can used in test code to modify the injected module.

By default all require statements in an injected module will be altered to be replaced with an injector, though if a replacement it not specified the default values will be used.

Examples

Given some code in a module like this:

// MyStore.js

var Dispatcher = require('lib/dispatcher');
var EventEmitter = require('events').EventEmitter;
var handleAction = require('lib/handle_action');

Dispatcher.register(handleAction, 'MyStore');

You can manipulate itโ€™s dependencies when you come to write tests as follows:

// If no flags are provided when using the loader then
// all require statements will be wrapped in an injector
MyModuleInjector = require('inject-loader!MyStore')
MyModule = MyModuleInjector({
  'lib/dispatcher': DispatcherMock,
  'events': EventsMock,
  'lib/handle_action': HandleActionMock
})

There are a few examples of complete test setups for both Webpack 1, 2, 3 & 4 in the example folder.

License

MIT (http://www.opensource.org/licenses/mit-license.php)

javascript
loader
webpack-loader

Contributors

plasticine

105 commits

TeaSeaLancs

3 commits

Aaronius

2 commits

nkovacs

1 commits

plasticine/inject-loader

๐Ÿ’‰๐Ÿ“ฆ A Webpack loader for injecting code into modules via their dependencies.

JavaScript

486

116 commits

updated Jun 20, 2026

See the code

README

ย 

๐Ÿ’‰๐Ÿ“ฆ

inject-loader

A Webpack loader for injecting code into modules via their dependencies

build status npm version npm downloads

Why

This is particularly useful for writing tests where mocking things inside your module-under-test is sometimes necessary before execution.

inject-loader was inspired by, and builds upon ideas introduced in jauco/webpack-injectable.

Usage

Documentation: Using loaders

Use the inject loader by adding the inject-loader! inline loader when you use require, this will return a function that can used in test code to modify the injected module.

By default all require statements in an injected module will be altered to be replaced with an injector, though if a replacement it not specified the default values will be used.

Examples

Given some code in a module like this:

// MyStore.js

var Dispatcher = require('lib/dispatcher');
var EventEmitter = require('events').EventEmitter;
var handleAction = require('lib/handle_action');

Dispatcher.register(handleAction, 'MyStore');

You can manipulate itโ€™s dependencies when you come to write tests as follows:

// If no flags are provided when using the loader then
// all require statements will be wrapped in an injector
MyModuleInjector = require('inject-loader!MyStore')
MyModule = MyModuleInjector({
  'lib/dispatcher': DispatcherMock,
  'events': EventsMock,
  'lib/handle_action': HandleActionMock
})

There are a few examples of complete test setups for both Webpack 1, 2, 3 & 4 in the example folder.

License

MIT (http://www.opensource.org/licenses/mit-license.php)

javascript
loader
webpack-loader

Contributors

plasticine

105 commits

TeaSeaLancs

3 commits

Aaronius

2 commits

nkovacs

1 commits

Languages

JavaScript

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Shell

5.2%