module-replace-webpack-plugin

0.0.12 verified Sat Apr 25 auth: no javascript abandoned

A webpack plugin (v0.0.12, latest as of 2025) that replaces imported modules at build time, allowing monkey patching of third-party libraries without modifying source code. Designed for webpack 3.x only. Uses regex-based matching to swap `require`/`import` statements. No updates since 2018; limited compatibility and no support for webpack 4+ or ESM. Different from string-replace-loader as it operates on module resolution rather than string substitution.

Common errors

error Error: ModuleReplaceWebpackPlugin is not a constructor ↓

cause Using ES module import instead of CommonJS require.

fix

Use const ModuleReplaceWebpackPlugin = require('module-replace-webpack-plugin');

error TypeError: Cannot read property 'push' of undefined ↓

cause options.modules is not an array or is missing.

fix

Ensure options contains modules: [{ test: /.../, replace: '...' }]

Warnings

deprecated Plugin only supports webpack 3.x; may break on webpack 4+. ↓

fix Upgrade to a modern alternative like string-replace-loader or NormalModuleReplacementPlugin.

gotcha The 'replace' path must be relative to root; does not automatically resolve from entry directory. ↓

fix Use path.resolve(__dirname, 'src/patched.js') to specify absolute path.

gotcha Multiple module rules are matched first-come-first-serve; overlapping regexes may cause unexpected replacement. ↓

fix Order specific regexes before generic ones in the modules array.

gotcha File extension in 'replace' is mandatory; omitting it will not work. ↓

fix Always include file extension, e.g., './patched.js' not './patched'.

Install

npm install module-replace-webpack-plugin

yarn add module-replace-webpack-plugin

pnpm add module-replace-webpack-plugin

Imports

ModuleReplaceWebpackPlugin

wrong

import ModuleReplaceWebpackPlugin from 'module-replace-webpack-plugin';

correct

const ModuleReplaceWebpackPlugin = require('module-replace-webpack-plugin');

Plugin does not provide ES module exports; use CommonJS require() only.

new ModuleReplaceWebpackPlugin(options)

wrong

new ModuleReplaceWebpackPlugin({ modules: { test: /lodash/, replace: './patched.js' } })

correct

new ModuleReplaceWebpackPlugin({ modules: [{ test: /lodash/, replace: './patched.js' }] })

options.modules must be an array of objects, not a single object.

exclude

wrong

new ModuleReplaceWebpackPlugin({ modules: [...], exclude: ['patched.js'] })

correct

new ModuleReplaceWebpackPlugin({ modules: [...], exclude: [/patched\.js$/] })

exclude must be an array of RegExp, not strings.

Quickstart

Configures webpack to replace all imports matching /lodash/ with a local patched file, excluding the patched file itself from replacement.

const ModuleReplaceWebpackPlugin = require('module-replace-webpack-plugin');
const path = require('path');

module.exports = {
  entry: './src/index.js',
  output: {
    filename: 'bundle.js',
    path: path.resolve(__dirname, 'dist')
  },
  plugins: [
    new ModuleReplaceWebpackPlugin({
      modules: [{
        test: /lodash/,
        replace: './src/patchedLodash.js'
      }],
      exclude: [/patchedLodash\.js$/]
    })
  ]
};