name: Coverage

on:
  pull_request_target:
    paths:
      - 'django/**/*.py'
      - 'tests/**/*.py'
    branches:
      - main

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

permissions:
  contents: read
  pull-requests: write

jobs:
  diff-coverage:
    if: github.repository == 'django/django'
    name: Diff Coverage (Windows)
    runs-on: windows-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v5
        with:
          fetch-depth: 0
          persist-credentials: false

      - name: Set up Python
        uses: actions/setup-python@v6
        with:
          python-version: '3.14'
          cache: 'pip'
          cache-dependency-path: 'tests/requirements/py3.txt'

      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip wheel
          python -m pip install -r tests/requirements/py3.txt -e .
          python -m pip install 'coverage[toml]' diff-cover

      - name: Run tests with coverage
        env:
          PYTHONPATH: ${{ github.workspace }}/tests
          COVERAGE_PROCESS_START: ${{ github.workspace }}/tests/.coveragerc
          RUNTESTS_DIR: ${{ github.workspace }}/tests
        run: |
          python -Wall tests/runtests.py -v2

      - name: Generate coverage report
        if: success()
        env:
          COVERAGE_RCFILE: ${{ github.workspace }}/tests/.coveragerc
          RUNTESTS_DIR: ${{ github.workspace }}/tests
        run: |
          python -m coverage combine
          python -m coverage report --show-missing
          python -m coverage xml -o tests/coverage.xml

      - name: Run diff-cover
        if: success()
        run: |
          if (Test-Path 'tests/coverage.xml') {
            diff-cover tests/coverage.xml --compare-branch=origin/main --fail-under=0 > tests/diff-cover-report.md
          } else {
            Set-Content -Path tests/diff-cover-report.md -Value 'No coverage.xml found; skipping diff-cover.'
          }

      - name: Post/update PR comment
        if: success()
        uses: actions/github-script@v8
        with:
          script: |
            const fs = require('fs');
            const reportPath = 'tests/diff-cover-report.md';
            let body = 'No coverage data available.';
            if (fs.existsSync(reportPath)) {
              body = fs.readFileSync(reportPath, 'utf8');
            }
            const commentBody = '### 📊 Coverage Report for Changed Files\n\n```\n' + body + '\n```\n\n**Note:** Missing lines are warnings only. Some lines may not be covered by SQLite tests as they are database-specific.\n\nFor more information about code coverage on pull requests, see the [contributing documentation](https://docs.djangoproject.com/en/dev/internals/contributing/writing-code/unit-tests/#code-coverage-on-pull-requests).';

            const { data: comments } = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
            });
            for (const c of comments) {
              if ((c.body || '').includes('📊 Coverage Report for Changed Files')) {
                await github.rest.issues.deleteComment({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  comment_id: c.id,
                });
              }
            }

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