webpack-merge

library6.0.1jsnpmunverified

A specialized merge library designed for webpack configuration objects. Version 6.0.1 is the current stable release, requiring Node >=18.0.0. Unlike generic merge utilities (e.g., Lodash.merge), it concatenates arrays, merges objects, and executes functions before merging—critical for webpack's plugin arrays and nested rules. Ships TypeScript types. Maintained actively, with minor/patch releases every few months.

devops serialization

npm install webpack-merge

github ↗package ↗

INSTALL

IMPORT

SIG · WEBPACK-MERGE

webpack-merge

devopsjavascriptv6.0.1

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

merge

✓ import { merge } from 'webpack-merge'

ESM default import pattern. Use named import for 'merge'.

merge

✓ const { merge } = require('webpack-merge')

✗ const merge = require('webpack-merge')

CommonJS requires destructuring; default export is an object with merge as a property.

mergeWithCustomize

✓ import { mergeWithCustomize } from 'webpack-merge'

Named export for custom merging behavior.

customizeArray

✓ import { customizeArray } from 'webpack-merge'

Named export; not a default.

Shows merging a common webpack config with environment-specific overrides using merge().

const { merge } = require('webpack-merge'); const common = { entry: './src/index.js', output: { filename: 'bundle.js' } }; const dev = { mode: 'development', devtool: 'inline-source-map' }; const prod = { mode: 'production', optimization: { minimize: true } }; const env = process.env.NODE_ENV || 'development'; const config = merge(common, env === 'development' ? dev : prod); module.exports = config;

Debug

Known issues

breakingIn v6, Node.js <18 is no longer supported.

fix

Upgrade Node.js to >=18.0.0 or stick with v5.

affects: <6.0.0

breakingDefault merge behavior changed: arrays are concatenated, not replaced.

fix

If you need replacement, use mergeWithCustomize with a customArray function that returns b instead of concatenating.

affects: >=1.0.0

deprecatedmerge.smart and merge.strategy removed in v5.

fix

Use mergeWithCustomize or merge() directly.

affects: >=5.0.0 <6.0.0

gotchaFunctions are executed before merging; if you pass a function returning a config, it will be called and merged.

fix

Wrap function-returning configs in an async wrapper only if you need async behavior; note Promises are not supported.

affects: >=1.0.0

gotchaObjects are merged deeply; nested objects are not replaced by default.

fix

Use mergeWithCustomize with customizeObject if you want replacement semantics.

affects: >=1.0.0

Errors

Common errors & fixes

Cannot find module 'webpack-merge'

Package not installed or incorrect import path in older versions.

fix

npm install webpack-merge@6.0.1 and use correct import syntax.

merge is not a function

CommonJS require without destructuring: const merge = require('webpack-merge') returns an object, not function.

fix

Use const { merge } = require('webpack-merge') or import { merge } from 'webpack-merge'.

TypeError: mergeWithCustomize is not a function

Importing as default when it's a named export.

fix

Import as named export: import { mergeWithCustomize } from 'webpack-merge'.

Upgrade

Version history

6.0.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

14 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/survivejs/webpack-merge ↗

packagehttps://www.npmjs.com/package/webpack-merge ↗