concat-merge

Recursively merge objects, especially for webpack/rollup configs.

Comparison

name	immutable	concat	dedupe	clone	multiple parameters	recommended
concat-merge	true	true	false	true	no	yes
merge-deep	true	true	true	true	yes	yes
deepmerge	true	true	false	false (option)	no
lodash/merge	false	false	false	true	yes
lodash/mergeWith	false	false (option)	false (option)	true	yes	yes

Install

npm install concat-merge

Usage

import concatMerge from 'concat-merge'

concatMerge(baseConfig, {
  input: 'entry.js',
  plugins: [inject({React: 'react'})],
})

lodash equivalent:

import mergeWith from 'lodash/mergeWith'

const concatMerge = (...args) =>
  mergeWith({}, ...args, (prev, next) => {
    if (Array.isArray(prev)) {
      return prev.concat(next)
    }
  })