rollup-plugin-combine

2.1.1 verified Mon Apr 27 auth: no javascript

A Rollup plugin that merges multiple JavaScript files into a single output, supporting both library and application builds. The current stable version is 2.1.1, released with a moderate cadence. It differentiates from similar plugins by offering fine-grained control over file ordering and custom transforms during concatenation. However, it lacks TypeScript support and is primarily used in legacy workflows where bundle splitting is not required.

Common errors

error TypeError: combine is not a function ↓

cause Using named import instead of default import.

fix

Use 'import combine from 'rollup-plugin-combine'' instead of 'import { combine } from ...'

error Error: The 'output' option must be specified. ↓

cause Missing required 'output' option in plugin configuration.

fix

Add 'output' property to the plugin options, e.g., output: 'bundle.js'

error Module not found: Can't resolve 'rollup-plugin-combine' ↓

cause Package not installed or missing from dependencies.

fix

Run 'npm install rollup-plugin-combine' and ensure it's in your package.json.

Warnings

gotcha Plugin does not support source maps; combining files may break debugging experience. ↓

fix Use alternative plugin with source map support or disable source maps in Rollup.

deprecated Option 'files' is deprecated, use 'include' instead. ↓

fix Rename 'files' to 'include' in plugin options.

breaking In v2, output option is required; previous versions allowed omission. ↓

fix Ensure 'output' is provided in plugin options.

Install

npm install rollup-plugin-combine

yarn add rollup-plugin-combine

pnpm add rollup-plugin-combine

Imports

default

wrong

import { combine } from 'rollup-plugin-combine'

correct

import combine from 'rollup-plugin-combine'

The default export is a function; named exports are not available.

default

wrong

const { combine } = require('rollup-plugin-combine')

correct

const combine = require('rollup-plugin-combine')

CommonJS require returns the default export.

type CombineOptions
```
import type { CombineOptions } from 'rollup-plugin-combine'
```
TypeScript users can import the options type for type safety, available since v2.

Quickstart

Combines two input files into a single output file using the plugin.

// rollup.config.js
import combine from 'rollup-plugin-combine';

export default {
  input: 'src/index.js',
  output: {
    dir: 'dist',
    format: 'esm'
  },
  plugins: [
    combine({
      files: ['src/utils.js', 'src/main.js'],
      output: 'dist/bundle.js'
    })
  ]
};