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Mimics a webpack config's filename extensions, aliases, and loaders inside of the current node process.

You might want to mimic.install():

  • instead of bundling your specs with webpack.
  • before using linter rules like eslint-plugin-require-path-exists.
  • when performing universal rendering with code you also plan to bundle with webpack.


npm install mimic-webpack


In your entry file:

var Mimic = require('mimic-webpack');
new Mimic({
    webpackConfig: { // pass your webpack config here 
        resolve: {
            extensions: ['.foo'],
            alias: {
                myModule: 'theirModule'
        module: {
            loaders: [{
                test: /\.foo$/,
                loader: 'foo-loader'

// code to be processed with foo-loader 

Now, anywhere in your project, you can do this:


In the above example:

  • theirModule is aliased to myModule due to resolve.alias
  • The .foo extension is inferred due to `resolve.extensions.
  • The module is processed with foo-loader because of module.loaders


  • Mimic.prototype.install - configures require in the current node process to behave according to the webpack config specified by options.webpackConfig passed to the constructor. Returns the current instance.
  • Mimic.prototype.uninstall - un-does what Mimic.prototype.install did. Returns the current instance.
  • Mimic.restore - restores configuration to the way it was before Mimic was required in.

known issues

Paths that were resolved using custom properties in require.extensions will continue to resolve the same even after Mimic.restore or Mimic.prototype.uninstall have been called.

require.resolve('theirModule'); // still resolves to 

current limitations

  • Loaders must be specified in the webpack config. Loaders specified on the require path will not work
  • install and uninstall can only be run once per instance.