nextjs_bundle_analysis.yaml

name: "Next.js Bundle Analysis"

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

defaults:
  run:
    # change this if your nextjs app does not live at the root of the repo
    working-directory: ./

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
  cancel-in-progress: true

jobs:
  analyze:
    runs-on: ubuntu-latest
    steps:
      - id: checkout
        name: Check out source code
        uses: actions/checkout@v3
        with:
          ref: ${{github.head_ref}}
          repository: ${{github.event.pull_request.head.repo.full_name}}

      - id: setup-node
        uses: actions/setup-node@v3
        with:
          node-version: '14'
          cache: 'npm'

      - name: Install dependencies
        run: |-
          echo "Running CI with "
          echo "Node version: $(node --version)"
          echo "NPM version: $(npm --version)"

          git config --global url."https://".insteadOf ssh://
          npm ci

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

      - name: Build project
        run: |-
          npm run build

      # 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

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

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

      # 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

      - name: Get comment body
        id: get-comment-body
        if: success() && github.event.number
        run: |
          body=$(cat .next/analyze/__bundle_analysis_comment.txt)

          # This sets multiline strings into the output variable
          # See https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#example-of-a-multiline-string
          echo "body<<EOF" >> "$GITHUB_OUTPUT"
          echo "$body" >> "$GITHUB_OUTPUT"
          echo "EOF" >> "$GITHUB_OUTPUT"

      - name: Find Comment
        uses: peter-evans/find-comment@v1
        if: success() && github.event.number
        id: fc
        with:
          issue-number: ${{ github.event.number }}
          body-includes: "<!-- __NEXTJS_BUNDLE -->"

      - name: Create Comment
        uses: peter-evans/create-or-update-comment@v1.4.4
        if: success() && github.event.number && steps.fc.outputs.comment-id == 0
        with:
          issue-number: ${{ github.event.number }}
          body: ${{ steps.get-comment-body.outputs.body }}

      - name: Update Comment
        uses: peter-evans/create-or-update-comment@v1.4.4
        if: success() && github.event.number && steps.fc.outputs.comment-id != 0
        with:
          issue-number: ${{ github.event.number }}
          body: ${{ steps.get-comment-body.outputs.body }}
          comment-id: ${{ steps.fc.outputs.comment-id }}
          edit-mode: replace