esbuild-bundle-analyzer GitHub Action

Analyzes each PR's impact on esbuild bundle size

Usage

GitHub Action setup for 🔐private repositories

name: esbuild-bundle-analyzer

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  analyze:
    runs-on: ubuntu-latest
    timeout-minutes: 5
    permissions:
      contents: read # for checkout repository
      actions: read # for fetching base branch bundle stats
      pull-requests: write # for comments
    steps:
    # Ensure you build your project before running this action
    # For example,
    - uses: actions/checkout@v4
    - uses: actions/setup-node@v4
      with:
        node-version: 20
        cache: 'npm'
        cache-dependency-path: subdir/package-lock.json
    - run: npm ci
    - name: Run esbuild
      run: npm run build
    
    # Call this action after the build
    - name: Analyze esbuild bundle size
      # uses: exoego/esbuild-bundle-analyzer@main # If you prefer nightly!
      uses: exoego/esbuild-bundle-analyzer@v1
      with:
        metafiles: "out/meta.json"

GitHub Action setup for public repositories

If your repository is public and you want to run this action on PRs from forks, you may need to use pull_request_target event. By using pull_request_target event, GitHub grant GitHub Actions to modify pull requests even on PRs from forks.

Warning

Please refer Permissions for the GITHUB_TOKEN and use this carefully.

name: esbuild-bundle-analyzer

on:
  push:
    branches: [main]
  pull_request_target:
    branches: [main]

jobs:
  # PLEASE AVOID ADDING OTHER JOBS IN THIS FILE
  # BECAUSE THIS ACTION USE `pull_request_target` EVENT that grants write permissions to GitHub Actions running on PRs from forks.
  analyze:
    runs-on: ubuntu-latest
    timeout-minutes: 5
    permissions:
      contents: read # for checkout repository
      actions: read # for fetching base branch bundle stats
      pull-requests: write # for comments    
    steps:
    # Ensure you build your project before running this action
    # For example,
    - uses: actions/checkout@v4
      with:
        # This is required to fetch the commit SHA of the forked PR
        ref: "${{ github.event.pull_request.merge_commit_sha }}"
    - uses: actions/setup-node@v4
      with:
        node-version: 20
        cache: 'npm'
        cache-dependency-path: subdir/package-lock.json
    - run: npm ci
    - name: Run esbuild
      run: npm run build
    
    # Call this action after the build
    - name: Analyze esbuild bundle size
      # uses: exoego/esbuild-bundle-analyzer@main # If you prefer nightly!
      uses: exoego/esbuild-bundle-analyzer@v1
      with:
        metafiles: "out/meta.json"

esbuild setup

You need to write meta file yourself after build.

If you use esbuild CLI, your build script in package.json should have --metafile=out/meta.json or such, something like this:

{
  "scripts": {
    "build": "esbuild ./src/lambda.ts --bundle --metafile=out/meta.json ......."
  },
  // ...
}

If you use esbuild API, something like this:

// esbuild.mjs
import * as esbuild from 'esbuild'
import fs from 'node:fs'

let result = await esbuild.build({
    entryPoints: ['src/app1.ts', 'src/app2.ts'],
    bundle: true,
    metafile: true,
    outdir: 'dist',
})

fs.writeFileSync('dist/meta.json', JSON.stringify(result.metafile))

For both cases, the metafiles input for GitHub Action will be "dist/meta.json".

If you have multiple meta files, you can specify them like this "dist/meta1.json,dist/meta2.json" or "dist/meta*.json.

Permissions

This action requires the following permissions:

permissions:
  contents: read # for checkout repository
  actions: read # for fetching base branch bundle stats
  pull-requests: write # for comments

This action uses the GITHUB_TOKEN provided by GitHub Actions. Due to security limitation, GITHUB_TOKEN is not granted to write comments on PRs from forks on pull_request event. Instead, pull_request_target event should be used on PRs from forks to overcome this limitation. Please check the above setup example to use this action with pull_request_target.

Action inputs

Name	Default	Description
metafiles	-	A required comma-separated list of paths to esbuild's meta file. Glob (dist/**/meta.json) is supported.
name	${{ github.event. repository.name }}	The name of your project. This will be used in the comment header.
analyze_directory	.analyzer	A path to working directory where bundle analysis are stored.
include_extensions	.js,.cjs,.mjs	A comma-separated list of file extension to be included in the analysis table.
percent_extra_attention	20	If an out file size has increased more than this percent, display a "‼️" to draw extra attention to the change.
include_size_comparison	added, deleted, increased, decreased, no-change	A comma-separated list of size comparison items to be displayed. Available filter are total, added, deleted, increased, decreased and no-change. If you are not interested in some of them, you can remove them from the list.
show_details	true	If true, a collapsed "details" section is rendered. It explains the details of the numbers provided and icons.
show_no_change	true	[DEPRECATED] Use the include_size_comparison list to show/hide no-change. If true, all bundles are shown in the analysis regardless of size change. If false, only bundles with size changes are shown.
top_n_largest_paths	20	The number of largest paths (e.g.) node_modules/foo) to be collected. If 0 or lower, skipped.

Action outputs

No outputs are provided by this action at this time.

Acknowledgements

• Highly inspired by hashicorp/nextjs-bundle-analysis

License

MIT