react.dev/.github/workflows/analyze.yml

name: Analyze Bundle

on:
  pull_request:
  push:
    branches:
      - main # change this if your default branch is named differently
  workflow_dispatch:

jobs:
  analyze:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2

      - name: Set up node
        uses: actions/setup-node@v1
        with:
          node-version: "14.x"

      - name: Install dependencies
        uses: bahmutov/npm-install@v1.7.10
        with:
          working-directory: 'beta'

      - name: Restore next build
        uses: actions/cache@v2
        id: restore-build-cache
        env:
          cache-name: cache-next-build
        with:
          path: beta/.next/cache
          # change this if you prefer a more strict cache
          key: ${{ runner.os }}-build-${{ env.cache-name }}

      - name: Build next.js app
        # change this if your site requires a custom build command
        run: ./node_modules/.bin/next build
        working-directory: beta

      # Here's the first place where next-bundle-analysis' own script is used
      # This step pulls the raw bundle stats for the current bundle
      - name: Analyze bundle
        run: npx -p nextjs-bundle-analysis report
        working-directory: beta

      - name: Upload bundle
        uses: actions/upload-artifact@v2
        with:
          path: beta/.next/analyze/__bundle_analysis.json
          name: bundle_analysis.json

      - name: Download base branch bundle stats
        uses: dawidd6/action-download-artifact@v2
        if: success() && github.event.number
        with:
          workflow: analyze.yml
          branch: ${{ github.event.pull_request.base.ref }}
          name: bundle_analysis.json
          path: beta/.next/analyze/base/bundle

      # And here's the second place - this runs after we have both the current and
      # base branch bundle stats, and will compare them to determine what changed.
      # There are two configurable arguments that come from package.json:
      #
      # - budget: optional, set a budget (bytes) against which size changes are measured
      #           it's set to 350kb here by default, as informed by the following piece:
      #           https://infrequently.org/2021/03/the-performance-inequality-gap/
      #
      # - red-status-percentage: sets the percent size increase where you get a red
      #                          status indicator, defaults to 20%
      #
      # Either of these arguments can be changed or removed by editing the `nextBundleAnalysis`
      # entry in your package.json file.
      - name: Compare with base branch bundle
        if: success() && github.event.number
        run: ls -laR .next/analyze/base && npx -p nextjs-bundle-analysis compare
        working-directory: beta

      - name: Upload analysis comment
        uses: actions/upload-artifact@v2
        with:
          name: analysis_comment.txt
          path: beta/.next/analyze/__bundle_analysis_comment.txt

      - name: Save PR number
        run: echo ${{ github.event.number }} > ./pr_number

      - name: Upload PR number
        uses: actions/upload-artifact@v2
        with:
          name: pr_number
          path: ./pr_number

      # The actual commenting happens in the other action, matching the guidance in
      # https://securitylab.github.com/research/github-actions-preventing-pwn-requests/