formatting.yml

name: Format code

on:
  pull_request:
    branches: [ master ]
    paths-ignore:
      - '**.md'
      - '.github/workflows/**'

env:
  java_version: '17'
  java_distribution: 'zulu'

jobs:
  formatting:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Set up JDK ${{ env.java_version }}-${{ env.java_distribution }}
        uses: actions/setup-java@v3
        with:
          java-version: ${{ env.java_version }}
          distribution: ${{ env.java_distribution }}

      - name: Cache Gradle packages
        uses: actions/cache@v3
        with:
          path: ~/.gradle/caches
          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle') }}
          restore-keys: ${{ runner.os }}-gradle

      - name: Run Spotless Check
        run: |
          ./gradlew spotlessCheck --quiet --continue 2>&1 | tee spotless-output.txt
          if grep -q "\.java" spotless-output.txt; then
            exit 1
          fi

      - name: Upload Spotless Output
        if: ${{ failure() }}
        uses: actions/upload-artifact@v4
        with:
          name: spotless-output
          path: spotless-output.txt

      - name: Extract Affected Files
        if: ${{ failure() }}
        run: |
          grep "\.java" spotless-output.txt > affected-files.txt || true

      - name: Comment PR if code does not comply to Google Java style guide
        if: ${{ failure() }}
        uses: actions/github-script@v6
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const fs = require('fs');
            const files = fs.existsSync('affected-files.txt') ? fs.readFileSync('affected-files.txt', 'utf8').trim().split('\n') : [];
            if (files.length === 0) return;

            const actionsDashboardUrl = `https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}`;

            const commentBody = `### 🚨 Code Formatting Issue 🚨\n\n`
              + `This contribution does not follow the conventions set by the [Google Java Style Guide](https://google.github.io/styleguide/javaguide.html).\n\n`
              + `Please run the following command at the root of the project to fix formatting errors:\n\n`
              + "```sh\n./gradlew spotlessApply\n```\n\n"
              + `<details><summary><strong>🗂️ Affected files</strong></summary>\n${files.map(file => `- \`${file.trim()}\``).join('\n')}</details>\n\n`
              + `[Go to the Actions Dashboard to download the full Spotless output](${actionsDashboardUrl})\n\n`;

            github.rest.issues.createComment({
              issue_number: context.issue.number,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: commentBody
            });