esbuild-plugin-assets-manifest

1.0.8 verified Fri May 01 auth: no javascript

esbuild plugin that generates a JSON manifest file mapping entry points to their output assets (JS, CSS, images, etc.), similar to assets-webpack-plugin for Webpack. Version 1.0.8 is the latest stable release. It requires esbuild as a peer dependency, builds output based on esbuild's metafile, and supports custom filenames, output paths, metadata injection, and custom processing via processOutput. Key differentiators: lightweight, no extra runtime dependencies, focused solely on manifest generation, and fully typed with TypeScript definitions.

Common errors

error Error: The plugin 'assets-manifest' must be called before build starts ↓

cause Attempting to call the plugin function as if it were a class (e.g., new assetsManifest())

fix

Call the function directly without 'new': assetsManifest({...})

error TypeError: assetsManifest is not a function ↓

cause Incorrect import syntax in ESM (e.g., using named import instead of default import)

fix

Use default import: import assetsManifest from 'esbuild-plugin-assets-manifest'

error Error: Build failed with 1 error: error: Invalid 'entryPoints': expected object ↓

cause Passed entryPoints as an array instead of an object

fix

Change entryPoints to an object: { app: './src/app.js' }

Warnings

gotcha Entry points must be an object (not array) for the manifest to include named entries. ↓

fix Use entryPoints: { app: './src/app.js' } instead of entryPoints: ['./src/app.js'].

gotcha metafile must be set to true in esbuild options for the plugin to work. ↓

fix Add metafile: true to your esbuild build options.

gotcha The plugin does not validate that the manifest path exists; ensure the output directory exists before build. ↓

fix Create the directory manually or use a plugin like esbuild-plugin-copy to ensure it exists.

gotcha When using publicPath, ensure it ends with '/' to avoid missing slashes in asset URLs. ↓

fix Set publicPath: '/static/' (trailing slash) instead of '/static'.

gotcha The manifest JSON may not include assets from code splitting or dynamic imports; only entry point outputs. ↓

fix If code splitting is used, additional processing may be needed; no built-in support.

Install

npm install esbuild-plugin-assets-manifest

yarn add esbuild-plugin-assets-manifest

pnpm add esbuild-plugin-assets-manifest

Imports

default

wrong

const { assetsManifest } = require('esbuild-plugin-assets-manifest')

correct

import assetsManifest from 'esbuild-plugin-assets-manifest'

Default export is a function. Named export none, so named destructured require fails.

default

const assetsManifest = require('esbuild-plugin-assets-manifest')

CommonJS require works fine.

default

import assetsManifest from 'esbuild-plugin-assets-manifest'

Both ESM and CJS supported.

Quickstart

Builds an entry point and generates a manifest JSON file with custom metadata and indentation.

const esbuild = require('esbuild');
const assetsManifest = require('esbuild-plugin-assets-manifest');

await esbuild.build({
  entryPoints: { app: './src/index.js' },
  outdir: 'dist',
  bundle: true,
  metafile: true,
  plugins: [
    assetsManifest({
      filename: 'manifest.json',
      path: './dist',
      metadata: { version: '1.0.0', builtAt: new Date().toISOString() },
      processOutput: (assets) => JSON.stringify(assets, null, 2),
    })
  ]
});