bench.yml

name: Continuous Benchmarks

on:
  push:
    branches: [main]
    paths:
      - 'src/**'
      - 'js/**'
      - 'benches/**'
      - 'Cargo.toml'
      - 'Cargo.lock'
      - 'package.json'
      - 'package-lock.json'
  pull_request:
    branches: [main]
    paths:
      - 'src/**'
      - 'js/**'
      - 'benches/**'
      - 'Cargo.toml'
      - 'Cargo.lock'
      - 'package.json'
      - 'package-lock.json'
  workflow_dispatch:

jobs:
  benchmark:
    name: Run Benchmarks
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: 'npm'

      - name: Install Rust
        uses: dtolnay/rust-toolchain@stable

      - name: Cache cargo
        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/bin/
            ~/.cargo/registry/index/
            ~/.cargo/registry/cache/
            ~/.cargo/git/db/
            target/
          key: ${{ runner.os }}-cargo-bench-${{ hashFiles('**/Cargo.lock') }}
          restore-keys: |
            ${{ runner.os }}-cargo-bench-

      - name: Install dependencies
        run: npm ci

      - name: Build native module
        run: npm run build
        continue-on-error: true

      - name: Generate REAL benchmark fixtures
        run: node benches/setup-fixtures.js

      - name: Run benchmarks on REAL fixtures
        run: npm run bench:ci

      - name: Download baseline results
        uses: dawidd6/action-download-artifact@v3
        with:
          workflow: bench.yml
          branch: main
          name: benchmark-baseline
          path: baseline/
        continue-on-error: true

      - name: Compare with baseline
        id: compare
        if: always()
        run: |
          if [ -f "baseline/bench-results.json" ]; then
            node scripts/compare-benchmarks.js \
              --current bench-results.json \
              --baseline baseline/bench-results.json \
              --threshold 10 \
              --output bench-comparison.json
          else
            echo "No baseline found, this will become the baseline"
            echo "regression=false" >> $GITHUB_OUTPUT
            echo "regressions=0" >> $GITHUB_OUTPUT
          fi
        continue-on-error: true

      - name: Comment PR with results
        if: github.event_name == 'pull_request'
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');

            let comment = '## Benchmark Results\n\n';

            try {
              const markdown = fs.readFileSync('bench-comparison.md', 'utf-8');
              comment += markdown;
            } catch (err) {
              comment += 'Benchmarks completed. See artifacts for details.\n';
            }

            try {
              const results = JSON.parse(fs.readFileSync('bench-results.json', 'utf-8'));
              comment += '\n### Current Run Summary\n\n';
              comment += `- **Node version:** ${results.nodeVersion}\n`;
              comment += `- **Platform:** ${results.platform}\n`;
              comment += `- **Patterns tested:** ${results.summary.totalPatterns}\n`;
              comment += `- **Avg glob time:** ${results.summary.avgGlobTime.toFixed(2)}ms\n`;
              comment += `- **Avg fast-glob time:** ${results.summary.avgFastGlobTime.toFixed(2)}ms\n`;
              if (results.summary.avgGloblinTime) {
                comment += `- **Avg globlin time:** ${results.summary.avgGloblinTime.toFixed(2)}ms\n`;
                comment += `- **Speedup vs glob:** ${results.summary.avgSpeedupVsGlob.toFixed(1)}x\n`;
              }
            } catch (err) {
              console.log('Could not read benchmark results:', err.message);
            }

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

            const existingComment = comments.find(c =>
              c.user.type === 'Bot' && c.body.includes('## Benchmark Results')
            );

            if (existingComment) {
              await github.rest.issues.updateComment({
                comment_id: existingComment.id,
                owner: context.repo.owner,
                repo: context.repo.repo,
                body: comment
              });
            } else {
              await github.rest.issues.createComment({
                issue_number: context.issue.number,
                owner: context.repo.owner,
                repo: context.repo.repo,
                body: comment
              });
            }

      - name: Fail if regression detected
        if: steps.compare.outputs.regression == 'true'
        run: |
          echo "Performance regression detected (>10%)"
          cat bench-comparison.md
          exit 1

      - name: Upload benchmark results
        uses: actions/upload-artifact@v4
        with:
          name: benchmark-results
          path: |
            bench-results.json
            bench-comparison.json
            bench-comparison.md
          retention-days: 30

      - name: Upload as baseline (main branch only)
        if: github.ref == 'refs/heads/main' && github.event_name == 'push'
        uses: actions/upload-artifact@v4
        with:
          name: benchmark-baseline
          path: bench-results.json
          retention-days: 90

      - name: Convert results to benchmark format
        if: github.ref == 'refs/heads/main' && github.event_name == 'push'
        run: |
          node -e "
            const fs = require('fs');
            const data = JSON.parse(fs.readFileSync('bench-results.json', 'utf-8'));
            const benchmarks = data.patterns.map(p => ({
              name: p.pattern + ' (' + p.fixture + ')',
              unit: 'ms',
              value: p.globlin ? p.globlin.mean : p.glob.mean,
              range: (p.globlin ? p.globlin.stdDev : p.glob.stdDev).toFixed(2) + ' ms',
              extra: 'Results: ' + (p.globlin ? p.globlin.resultCount : p.glob.resultCount)
            }));
            fs.writeFileSync('benchmark-data.json', JSON.stringify(benchmarks, null, 2));
          "

      - name: Store benchmark result for tracking
        if: github.ref == 'refs/heads/main' && github.event_name == 'push'
        uses: benchmark-action/github-action-benchmark@v1
        with:
          name: Globlin Benchmarks
          tool: 'customSmallerIsBetter'
          output-file-path: benchmark-data.json
          github-token: ${{ secrets.GITHUB_TOKEN }}
          auto-push: true
          alert-threshold: '150%'
          comment-on-alert: true
          fail-on-alert: false
          gh-pages-branch: gh-pages
          benchmark-data-dir-path: dev/bench
        continue-on-error: true