action.yml

name: "Python Mutation Report"
description: "Comment on the PR with mutation test results for changed lines. This will swiftly identify untested areas."
inputs:
  lock-file-path:
    description: "Path of lock file to generate requirements.txt"
    required: true
  src-directory:
    description: "Path of source directory to be mutated"
    required: true
  test-directory:
    description: "Path of test directory"
    required: true
  where-to-run-test:
    description: "Where to run the test. If none is specified, run from the root directory."
    required: false
    default: "."
  python-version:
    description: "Python version to use. Default is 3.11."
    required: false
    default: "3.11"
branding:
  icon: "check-circle"
  color: "green"
runs:
  using: "composite"
  steps:
    - name: Validate checkout action has been done in advance
      run: |
        if [ -z "$(ls -A)" ]; then
          echo "Error: File or folder not found under workspace. Repository needs to be checked out in advance, have you done it?"
          exit 1
        fi
      shell: bash

    - name: Validate input parameters is not empty
      run: |
        [[ "${{ inputs.lock-file-path }}" ]] || { echo "Error: lock-file-path input is empty" ; exit 1; }
        [[ "${{ inputs.src-directory }}" ]] || { echo "Error: src-directory input is empty" ; exit 1; }
        [[ "${{ inputs.test-directory }}" ]] || { echo "Error: test-directory input is empty" ; exit 1; }
      shell: bash

    - name: Validate trigger event is pull_request
      if: ${{ github.event_name != 'pull_request' }}
      run: |
        echo "This workflow is supposed to work on pull request events, but it worked on ${{ github.event_name }}"
        exit 1
      shell: bash

    - name: Validate input parameters are directories or files
      run: |
        [ -f "${{ inputs.lock-file-path }}" ] || { echo "Error: lock-file-path is not a file" ; exit 1; }
        [ -d "${{ inputs.src-directory }}" ] || { echo "Error: src-directory is not a directory" ; exit 1; }
        [ -d "${{ inputs.test-directory }}" ] || { echo "Error: test-directory is not a directory" ; exit 1; }
        [ -d "${{ inputs.where-to-run-test }}" ] || { echo "Error: where-to-run-test is not a directory" ; exit 1; }
      shell: bash

    - name: Output changed filenames to txt
      env:
        GITHUB_TOKEN: ${{ github.token }}
        URL: ${{ github.event.pull_request.html_url }}
      run: gh pr diff "${URL}" --name-only > "${{ github.action_path }}/temporary/PR_diff_filenames.txt"
      # Strings with \n cannot be set in $GITHUB_OUTPUT or $GITHUB_ENV, so use a text file instead.
      shell: bash

    - name: Output diff contents to txt
      env:
        GH_TOKEN: ${{ github.token }}
        URL: ${{ github.event.pull_request.html_url }}
      run: gh pr diff "${URL}" > "${{ github.action_path }}/temporary/PR_diff_contents.txt"
      shell: bash

    - name: Make mutmut run command from PR changed files
      # It needs to be run from the root of the repository as it retrieves the files under src and test with glob.
      run: python3 "${{ github.action_path }}/scripts/make_command_of_run.py"
      env:
        SRC_DIRECTORY: ${{ inputs.src-directory }}
        TEST_DIRECTORY: ${{ inputs.test-directory }}
        COMPOSITE_ACTION_PATH: ${{ github.action_path }}
        WORKSPACE_PATH: ${{ github.workspace }}
      shell: bash

    - name: Set up Python
      uses: actions/setup-python@v5
      with:
        python-version: "${{ inputs.python-version }}"

    - name: Install actions repository dependencies
      run: |
        sed '/-e/d' "${{ github.action_path }}/requirements.lock" > "${{ github.action_path }}/requirements.txt"
        pip3 install --no-cache-dir -r "${{ github.action_path }}/requirements.txt"
      shell: bash
      # pytest may not need to be installed if it is already installed in the lock file

    - name: Generate requirements.txt
      # Uses the path of the lock file from root, so must be run from root.
      run: python3 "${{ github.action_path }}/scripts/generate_requirements.py"
      env:
        LOCK_FILE_PATH: ${{ inputs.lock-file-path }}
      shell: bash

    - name: Install caller repository dependencies
      run: pip3 install --no-cache-dir -r requirements.txt
      shell: bash

    - name: Create __init__.py in test directory if src and test are not same directory
      run: |
        src_absolute_path=$(readlink -f "${{ inputs.src-directory }}")
        test_absolute_path=$(readlink -f "${{ inputs.test-directory }}")

        if [ "$src_absolute_path" != "$test_absolute_path" ]; then
          echo "The src and test paths point to different locations. So, creating __init__.py in test-directory."
          cd "${{ inputs.test-directory }}"
          find . -name '__pycache__' -prune -o -type d -exec touch {}/__init__.py \;
        else
          echo "The src and test paths point to the same location. So, skipping the creation of __init__.py."
        fi
      shell: bash
      # Create __init__.py because import errors occur when trying to run only some test files.
      # However, if src and test are in the same directory, the generation of __int__.py causes import errors.

    - name: Generate pre mutation mutmut config to plant mutants in the changed line only
      env:
        WHERE_TO_RUN_TEST: ${{ inputs.where-to-run-test }}
        COMPOSITE_ACTION_PATH: ${{ github.action_path }}
        WORKSPACE_PATH: ${{ github.workspace }}
      run: python3 "${{ github.action_path }}/scripts/generate_pre_mutation_config.py"
      shell: bash

    - name: Execute mutation test
      run: |
        cd "${{ inputs.where-to-run-test }}"
        if [ -f .mutmut-cache ]; then
          echo "Removing .mutmut-cache" ; rm .mutmut-cache;
        fi
        bash "${{ github.action_path }}/temporary/mutmut-run.sh"
      shell: bash
      continue-on-error: true
      # If all mutants cannot be killed, an error occurs with an exit code of 2.
      # Even if an error occurs, continue-on-error is required to allow subsequent steps to be performed

    - name: Output mutation test result to a text file.
      run: |
        cd "${{ inputs.where-to-run-test }}"
        mutmut html ; mv html "${{ github.action_path }}/temporary";
        mutmut junitxml --suspicious-policy=error > "${{ github.action_path }}/temporary/junit.xml"
      shell: bash
      # Move html directory to temporary directory?

    - name: Reshape result for PR comment
      run: python3 "${{ github.action_path }}/scripts/reshape_result_for_PR_comment.py"
      env:
        COMPOSITE_ACTION_PATH: ${{ github.action_path }}
        WORKSPACE_PATH: ${{ github.workspace }}
      shell: bash

    - name: Post comments to PR
      env:
        GITHUB_TOKEN: ${{ github.token }}
        URL: ${{ github.event.pull_request.html_url }}
      run: gh pr comment "${URL}" --body-file "${{ github.action_path }}/temporary/PR_comment.txt"
      shell: bash