coverage-comment.yml

name: Post Coverage Comment

on:
  workflow_run:
    workflows: ["Run Unit Tests"]
    types:
      - completed

permissions:
  pull-requests: write
  actions: read

jobs:
  comment:
    runs-on: ubuntu-latest
    if: >
      github.event.workflow_run.event == 'pull_request' &&
      github.event.workflow_run.conclusion == 'success'
    steps:
      - name: Download Coverage Artifacts
        uses: actions/download-artifact@v4
        with:
          run-id: ${{ github.event.workflow_run.id }}
          github-token: ${{ secrets.GITHUB_TOKEN }}
          name: coverage-data
      
      - name: Upload Coverage Report
        id: upload-report
        uses: actions/upload-artifact@v4
        with:
          name: coverage-report
          path: coverage/
          retention-days: 14

      - name: Post Comment
        uses: actions/github-script@v6
        env:
          ARTIFACT_URL: ${{ steps.upload-report.outputs.artifact-url }}
        with:
          script: |
            const fs = require('fs');

            const { owner, repo } = context.repo;
            const headSha = context.payload.workflow_run.head_commit.id;

            const loadSummary = (path) => {
              try {
                return JSON.parse(fs.readFileSync(path, 'utf8'));
              } catch (e) {
                console.log(`Could not read ${path}: ${e}`);
                return null;
              }
            };

            const baseSummary = loadSummary('./coverage-base-summary.json');
            const prSummary = loadSummary('./coverage-pr-summary.json');

            if (!baseSummary || !prSummary) {
              console.log("Missing coverage data, skipping comment.");
              return;
            }

            let markdown = `### 🧪 Code Coverage\n\n`;
            
            markdown += `[⬇️ **Download Full Report**](${process.env.ARTIFACT_URL})\n\n`;

            const metric = 'statements';
            const getPct = (summaryItem, m) => summaryItem && summaryItem[m] ? summaryItem[m].pct : 0;
            
            const formatDiff = (oldPct, newPct) => {
              const diff = (newPct - oldPct).toFixed(2);
              
              let icon = '';
              if (diff > 0) icon = '🟢';
              else if (diff < 0) icon = '🔴';
              else icon = '⚪️';

              const diffStr = diff > 0 ? `+${diff}%` : `${diff}%`;
              return `${icon} ${diffStr}`;
            };

            const fileUrl = (path) => `https://github.com/${owner}/${repo}/blob/${headSha}/${path}`;

            const allFiles = new Set([...Object.keys(baseSummary), ...Object.keys(prSummary)]);
            allFiles.delete('total');
            const workspacePath = process.env.GITHUB_WORKSPACE ? process.env.GITHUB_WORKSPACE + '/' : ''; 

            let changedRows = [];
            let newRows = [];
            
            for (const file of allFiles) {
              const baseFile = baseSummary[file];
              const prFile = prSummary[file];

              if (!prFile) continue;

              const oldPct = getPct(baseFile, metric);
              const newPct = getPct(prFile, metric);

              const relativeFilePath = file.replace(workspacePath, '');
              const linkedPath = `[${relativeFilePath}](${fileUrl(relativeFilePath)})`;

              if (!baseFile && prFile) {
                newRows.push(`| ${linkedPath} (**new**) | — | ${newPct}% | — |\n`);
              } else if (oldPct !== newPct) {
                changedRows.push(`| ${linkedPath} | ${oldPct}% | ${newPct}% | ${formatDiff(oldPct, newPct)} |\n`);
              }
            }

            if (changedRows.length === 0 && newRows.length === 0) {
              markdown += `\n_No coverage changes._\n`;
            } else {
              markdown += `| | Base | PR | Delta |\n`;
              markdown += `| :--- | :---: | :---: | :---: |\n`;
              
              if (changedRows.length > 0) {
                markdown += changedRows.sort().join('');
              }
              if (newRows.length > 0) {
                markdown += newRows.sort().join('');
              }

              const oldTotalPct = getPct(baseSummary.total, metric);
              const newTotalPct = getPct(prSummary.total, metric);
              if (oldTotalPct !== newTotalPct) {
                markdown += `| **Total** | ${oldTotalPct}% | ${newTotalPct}% | ${formatDiff(oldTotalPct, newTotalPct)} |\n`;
              }
            }

            markdown += `\n\n_Generated by [coverage-comment.yml](https://github.com/a2aproject/a2a-js/actions/workflows/coverage-comment.yml)_`;

            const prNumber = fs.readFileSync('./PR_NUMBER', 'utf8').trim();

            if (!prNumber) {
              console.log("No PR number found.");
              return;
            }

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

            const existingComment = comments.data.find(c => 
              c.body.includes('Generated by [coverage-comment.yml]') && 
              c.user.type === 'Bot'
            );

            if (existingComment) {
              await github.rest.issues.updateComment({
                owner,
                repo,
                comment_id: existingComment.id,
                body: markdown
              });
            } else {
              await github.rest.issues.createComment({
                owner,
                repo,
                issue_number: prNumber,
                body: markdown
              });
            }