coverage-comment.yml

name: Coverage Comment

on:
  workflow_run:
    workflows:
      - CI - Lint and Test
    types:
      - completed

permissions:
  actions: read
  contents: read
  pull-requests: write
  issues: write

jobs:
  post-coverage-comment:
    name: Post Coverage Comment
    runs-on: ubuntu-latest
    if: ${{ github.event.workflow_run.event == 'pull_request' }}

    steps:
      - name: Download backend coverage
        uses: actions/download-artifact@v4
        with:
          name: backend-coverage
          path: backend-coverage
          run-id: ${{ github.event.workflow_run.id }}
          github-token: ${{ secrets.GITHUB_TOKEN }}
        continue-on-error: true

      - name: Download frontend coverage
        uses: actions/download-artifact@v4
        with:
          name: frontend-coverage
          path: frontend-coverage
          run-id: ${{ github.event.workflow_run.id }}
          github-token: ${{ secrets.GITHUB_TOKEN }}
        continue-on-error: true

      - name: Generate coverage report comment
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const fs = require('fs');

            const pullRequests = context.payload.workflow_run.pull_requests || [];

            if (!pullRequests.length) {
              core.info('No pull request found for this workflow run, skipping coverage comment.');
              return;
            }

            const issueNumber = pullRequests[0].number;
            const { owner, repo } = context.repo;
            const headSha = context.payload.workflow_run.head_sha || '';
            const shortSha = headSha ? headSha.slice(0, 7) : context.payload.workflow_run.id;

            const readCoverage = (filePath) => {
              try {
                const raw = fs.readFileSync(filePath, 'utf8');
                const parsed = JSON.parse(raw);
                const total = parsed.total || parsed;
                return { available: true, total };
              } catch (error) {
                core.info(`Coverage not available at ${filePath}: ${error.message}`);
                return {
                  available: false,
                  total: { lines: { pct: 0 }, statements: { pct: 0 }, functions: { pct: 0 }, branches: { pct: 0 } }
                };
              }
            };

            const backendCoverage = readCoverage('backend-coverage/coverage-summary.json');
            const frontendCoverage = readCoverage('frontend-coverage/coverage-summary.json');

            const getBadge = (percentage) => {
              if (percentage >= 80) return '🟢';
              if (percentage >= 70) return '🟡';
              return '🔴';
            };

            const formatPct = (value) => (typeof value === 'number' ? value.toFixed(2) : '0.00');

            const formatSection = (label, coverage) => {
              if (!coverage.available) {
                return `### ${label}\n⚠️ Coverage data not available (tests may have failed)\n\n`;
              }

              const total = coverage.total;
              return `### ${label}\n| Type | Coverage | Status |\n|------|----------|--------|\n| Lines | ${formatPct(total.lines.pct)}% | ${getBadge(total.lines.pct)} |\n| Statements | ${formatPct(total.statements.pct)}% | ${getBadge(total.statements.pct)} |\n| Functions | ${formatPct(total.functions.pct)}% | ${getBadge(total.functions.pct)} |\n| Branches | ${formatPct(total.branches.pct)}% | ${getBadge(total.branches.pct)} |\n\n`;
            };

            const backendSection = formatSection('Backend Coverage', backendCoverage);
            const frontendSection = formatSection('Frontend Coverage', frontendCoverage);

            const backendPass = backendCoverage.available && backendCoverage.total.lines.pct >= 70;
            const frontendPass = frontendCoverage.available && frontendCoverage.total.lines.pct >= 70;

            let comment = '## 📊 Test Coverage Report\n\n';
            comment += backendSection;
            comment += frontendSection;
            comment += '### Coverage Requirements\n';
            comment += '- **Minimum threshold:** 70% line coverage\n';
            comment += `- **Backend:** ${backendPass ? '✅ Passes' : backendCoverage.available ? '❌ Fails (below 70%)' : '⚠️ Not available'}\n`;
            comment += `- **Frontend:** ${frontendPass ? '✅ Passes' : frontendCoverage.available ? '❌ Fails (below 70%)' : '⚠️ Not available'}\n\n`;

            if (!backendPass || !frontendPass) {
              comment += '> ⚠️ Coverage thresholds are not met.\n\n';
            }

            comment += `---\n*Coverage report generated for commit ${shortSha}*`;

            const { data: comments } = await github.rest.issues.listComments({
              owner,
              repo,
              issue_number: issueNumber,
            });

            const existing = comments.find((comment) =>
              comment.user.type === 'Bot' && comment.body.includes('Test Coverage Report')
            );

            if (existing) {
              await github.rest.issues.updateComment({
                owner,
                repo,
                comment_id: existing.id,
                body: comment,
              });
            } else {
              await github.rest.issues.createComment({
                owner,
                repo,
                issue_number: issueNumber,
                body: comment,
              });
            }