check-for-tests-in-prs

action.yml

name: Check and Comment on Missing Tests
description: Checks if changed .dart files in a PR have corresponding _test.dart files and comments on the PR if tests are missing.
inputs:
  github-token:
    description: 'GitHub token to post comments'
    required: true
outputs:
  missing_tests:
    description: 'List of files missing tests'

runs:
  using: "composite"
  steps:
    # Step 1: Check out the repository
    - name: Check out the repository
      uses: actions/checkout@v2

    # Step 2: Identify changed .dart files
    - name: Identify changed .dart files
      id: identify-changes
      shell: bash
      run: |
        # Get a list of all added or modified .dart files in the PR
        git diff --name-only --diff-filter=AM origin/master | grep '\.dart$' > changed_files.txt || true
        
        # Check if changed_files.txt is empty
        if [[ ! -s changed_files.txt ]]; then
          echo "No .dart files have been modified or added."
          # Set an environment variable to indicate no files were found
          echo "no_changed_files=true" >> $GITHUB_ENV
        else
          # Output the changed files for debugging
          echo "Changed .dart files:"
          cat changed_files.txt
          echo "no_changed_files=false" >> $GITHUB_ENV
        fi

    # Step 3: Check for corresponding test files
    - name: Check for corresponding test files
      id: check-tests
      if: env.no_changed_files == 'false'
      shell: bash
      run: |
        # Initialize an empty variable to store files without corresponding tests
        missing_tests=""

        # Loop over each changed .dart file
          while IFS= read -r file; do
            # Skip files that do not start with lib/ unless they are in the test/ directory
            if [[ ! $file =~ ^lib/ && ! $file =~ ^test/ ]]; then
              continue
            fi
        
            # Further exclude specific patterns within the lib/ directory
            if [[ $file =~ \.g\.dart$ || $file =~ \.freezed\.dart$ || $file =~ ^lib/localization/ ]]; then
              continue
            fi
        
            # Check if the file is not a test file and whether it has a corresponding _test.dart file
            if [[ ! $file =~ _test\.dart$ ]]; then
              test_file="${file%.*}_test.dart"
              if ! grep -q "$test_file" changed_files.txt; then
                missing_tests="${missing_tests}${file}\n"
              fi
            fi
          done < changed_files.txt


        # Use GITHUB_ENV to set the missing_tests output
        echo "missing_tests=${missing_tests}" >> $GITHUB_ENV

        # Debugging: Output the files missing tests
        echo "Files missing tests:"
        echo "${missing_tests}"

    # Step 4: Comment on PR if tests are missing
    - name: Comment on PR if tests are missing
      if: ${{ env.missing_tests != '' }}
      uses: actions/[email protected]
      with:
        github-token: ${{ inputs.github-token }}
        script: |
          const missingFiles = `${{ env.missing_tests }}`.split('\n').filter(file => file);
          
          let body = '👋 Hi there!';
          if (missingFiles.length > 0) {
            body += `\n\n🚨 It looks like you've added or modified some files without adding corresponding tests:\n${missingFiles.map(file => `- ${file}`).join('\n')}`;
            body += `\n\n**However, there are some cases where you might not need to add or modify tests:**\n`;
            body += `- The PR is solely focused on **refactoring** existing fully covered code without changing functionality.\n`;
            body += `- The PR involves **documentation updates** or **comments** that do not affect code execution.\n`;
            body += `- The PR is making **non-functional changes** like formatting, renaming variables, or improving code readability.\n`;
            body += `- The untested files are pure entity classes or data models without business logic.\n`;
            body += `- The existing tests already cover the changes, and no new tests are necessary.\n\n`;
            body += `If any of these apply, feel free to dismiss this warning. 👍\n`;
          } else {
            body += `\n\n✅ Great job! All modified files have corresponding tests.`;
          }

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