ci.yaml

name: Merge Checks
run-name: ${{ github.actor }} is testing out GitHub Actions 🚀
on:
  pull_request:
    branches:
      - main
jobs:
  lint-and-test:
    permissions:
      checks: write
      pull-requests: write
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Use Node.js 20
        uses: actions/setup-node@v4
        with:
          node-version: 20

      # Re-use node_modules between runs until package-lock.json changes.
      - name: Cache node_modules
        id: cache-node_modules
        uses: actions/cache@v4
        with:
          path: node_modules
          key: node_modules-${{ hashFiles('package-lock.json') }}

      # Re-use ~/.elm between runs until elm.json or review/elm.json changes.
      # The Elm compiler saves downloaded Elm packages to ~/.elm saves
      # downloaded tool executables there.
      - name: Cache ~/.elm
        uses: actions/cache@v4
        with:
          path: ~/.elm
          key: elm-${{ hashFiles('elm.json', 'review/elm.json') }}

      # Install npm packages, unless we restored them from cache.
      # Since `npm ci` removes the node_modules folder before running it’s
      # important to skip this step if cache was restored.
      - name: npm ci
        if: steps.cache-node_modules.outputs.cache-hit != 'true'
        run: npm ci

      - name: Format
        run: npm run format
      - name: Review
        run: npm run review
      - name: Test
        run: npm run test

  diff-generation:
    permissions:
      checks: write
      pull-requests: write
    runs-on: ubuntu-latest
    steps:
      - name: Use Node.js 20
        uses: actions/setup-node@v4
        with:
          node-version: 20

      - name: Checkout branch
        uses: actions/checkout@v4
        with:
          path: branch
      
      - name: Checkout main
        uses: actions/checkout@v4
        with:
          ref: main
          path: main

      # Re-use node_modules between runs until package-lock.json changes.
      - name: Cache node_modules (branch)
        id: cache-node_modules-branch
        uses: actions/cache@v4
        with:
          path: branch/node_modules
          key: node_modules-${{ hashFiles('branch/package-lock.json') }}

      # Re-use node_modules between runs until package-lock.json changes.
      - name: Cache node_modules (main)
        id: cache-node_modules-main
        uses: actions/cache@v4
        with:
          path: main/node_modules
          key: node_modules-${{ hashFiles('main/package-lock.json') }}

      # Re-use ~/.elm between runs until elm.json or review/elm.json changes.
      # The Elm compiler saves downloaded Elm packages to ~/.elm saves
      # downloaded tool executables there.
      - name: Cache ~/.elm (both)
        uses: actions/cache@v4
        with:
          path: ~/.elm
          key: elm-${{ hashFiles('main/elm.json', 'main/review/elm.json', 'branch/elm.json', 'branch/review/elm.json') }}

      # Install npm packages, unless we restored them from cache.
      # Since `npm ci` removes the node_modules folder before running it’s
      # important to skip this step if cache was restored.
      - name: npm ci (branch)
        if: steps.cache-node_modules-branch.outputs.cache-hit != 'true'
        working-directory: branch
        run: npm ci

      # Install npm packages, unless we restored them from cache.
      # Since `npm ci` removes the node_modules folder before running it’s
      # important to skip this step if cache was restored.
      - name: npm ci (main)
        if: steps.cache-node_modules-main.outputs.cache-hit != 'true'
        working-directory: main
        run: npm ci
  
      - name: Generate (branch)
        working-directory: branch
        run: npm run test:gen
  
      - name: Generate (main)
        working-directory: main
        run: npm run test:gen || true # We don't want to block on main failing to generate

      - name: Diff the outputs
        run: |
          echo '```diff' > diff.md
          diff -w -d -r main/generated branch/generated | dd bs=1024 count=30 >> diff.md || true # We ignore diff exiting with a 1 on diff
          echo -e '\n```' >> diff.md

      - name: Post a comment with the diff
        uses: JoseThen/comment-pr@v1.2.0
        with:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          file_path: './diff.md'