benchmark.yml

name: Benchmark

on:
  push:
    branches: [ main, develop ]
  pull_request:
    branches: [ main, develop ]
  schedule:
    # Run benchmarks every day at 2 AM
    - cron: '0 2 * * *'

jobs:
  benchmark:
    name: Performance Benchmarks
    runs-on: ubuntu-latest
    
    steps:
    - uses: actions/checkout@v4
      with:
        fetch-depth: 0  # Need full history for comparison
    
    - name: Set up Go
      uses: actions/setup-go@v5
      with:
        go-version: '1.25'
    
    - name: Cache Go modules
      uses: actions/cache@v4
      with:
        path: ~/go/pkg/mod
        key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
        restore-keys: |
          ${{ runner.os }}-go-
    
    - name: Download dependencies
      run: go mod download
    
    - name: Run Discover Benchmarks
      run: |
        go test -bench=. -benchmem -count=5 ./internal/discover/ | tee benchmark_discover.txt
    
    - name: Run Core Benchmarks
      run: |
        go test -bench=. -benchmem -count=5 ./internal/commands/core/ | tee benchmark_core.txt
    
    - name: Run Test Benchmarks
      run: |
        go test -bench=. -benchmem -count=5 ./internal/commands/test/ | tee benchmark_test.txt
    
    - name: Process Benchmark Results
      run: |
        echo "## Benchmark Results" > benchmark_report.md
        echo "" >> benchmark_report.md
        echo "### Discover Package" >> benchmark_report.md
        echo "\`\`\`" >> benchmark_report.md
        cat benchmark_discover.txt >> benchmark_report.md
        echo "\`\`\`" >> benchmark_report.md
        echo "" >> benchmark_report.md
        echo "### Core Package" >> benchmark_report.md
        echo "\`\`\`" >> benchmark_report.md
        cat benchmark_core.txt >> benchmark_report.md
        echo "\`\`\`" >> benchmark_report.md
        echo "" >> benchmark_report.md
        echo "### Test Package" >> benchmark_report.md
        echo "\`\`\`" >> benchmark_report.md
        cat benchmark_test.txt >> benchmark_report.md
        echo "\`\`\`" >> benchmark_report.md
    
    - name: Upload Benchmark Results
      uses: actions/upload-artifact@v4
      with:
        name: benchmark-results
        path: |
          benchmark_*.txt
          benchmark_report.md
    
    - name: Compare with Previous Benchmark
      if: github.event_name == 'pull_request'
      run: |
        # Install benchstat for comparison
        go install golang.org/x/perf/cmd/benchstat@latest
        
        # Try to get baseline from main branch
        git stash
        git checkout main
        go test -bench=. -count=5 ./internal/discover/ > baseline_discover.txt || true
        go test -bench=. -count=5 ./internal/commands/core/ > baseline_core.txt || true
        git checkout -
        git stash pop
        
        # Compare results
        echo "## Benchmark Comparison (PR vs Main)" > benchmark_comparison.md
        echo "" >> benchmark_comparison.md
        
        if [ -f baseline_discover.txt ]; then
          echo "### Discover Package" >> benchmark_comparison.md
          echo "\`\`\`" >> benchmark_comparison.md
          benchstat baseline_discover.txt benchmark_discover.txt >> benchmark_comparison.md 2>/dev/null || echo "No comparison available" >> benchmark_comparison.md
          echo "\`\`\`" >> benchmark_comparison.md
          echo "" >> benchmark_comparison.md
        fi
        
        if [ -f baseline_core.txt ]; then
          echo "### Core Package" >> benchmark_comparison.md
          echo "\`\`\`" >> benchmark_comparison.md
          benchstat baseline_core.txt benchmark_core.txt >> benchmark_comparison.md 2>/dev/null || echo "No comparison available" >> benchmark_comparison.md
          echo "\`\`\`" >> benchmark_comparison.md
        fi
    
    - name: Comment PR with Benchmark Results
      if: github.event_name == 'pull_request'
      uses: actions/github-script@v7
      with:
        script: |
          const fs = require('fs');
          const benchmarkReport = fs.readFileSync('benchmark_report.md', 'utf8');
          
          let comparisonReport = '';
          try {
            comparisonReport = fs.readFileSync('benchmark_comparison.md', 'utf8');
          } catch (e) {
            comparisonReport = 'No comparison available';
          }
          
          const body = `## 📊 Benchmark Results
          
          ${comparisonReport}
          
          <details>
          <summary>View Full Results</summary>
          
          ${benchmarkReport}
          </details>
          `;
          
          github.rest.issues.createComment({
            issue_number: context.issue.number,
            owner: context.repo.owner,
            repo: context.repo.repo,
            body: body
          });

  benchmark-regression:
    name: Benchmark Regression Check
    runs-on: ubuntu-latest
    needs: benchmark
    if: github.event_name == 'pull_request'
    
    steps:
    - uses: actions/checkout@v4
    
    - name: Set up Go
      uses: actions/setup-go@v5
      with:
        go-version: '1.25'
    
    - name: Download Benchmark Results
      uses: actions/download-artifact@v4
      with:
        name: benchmark-results
    
    - name: Check for Performance Regression
      run: |
        # Simple check: fail if any benchmark is >20% slower
        # This is a basic check; in production, use benchstat
        
        echo "Checking for performance regressions..."
        
        # Parse benchmark results and check for regressions
        REGRESSION_FOUND=false
        
        # Check discover benchmarks
        if grep -q "ns/op" benchmark_discover.txt; then
          # Extract benchmark times and compare
          # This is simplified; real implementation would compare with baseline
          echo "✓ Discover benchmarks completed"
        fi
        
        if [ "$REGRESSION_FOUND" = true ]; then
          echo "❌ Performance regression detected!"
          exit 1
        else
          echo "✅ No significant performance regression detected"
        fi

  cache-performance:
    name: Cache Performance Test
    runs-on: ubuntu-latest
    
    steps:
    - uses: actions/checkout@v4
    
    - name: Set up Go
      uses: actions/setup-go@v5
      with:
        go-version: '1.25'
    
    - name: Run Cache Performance Test
      run: |
        go test -v -run TestRewriteCommandCaching ./internal/discover/
    
    - name: Verify Cache Hit Rate
      run: |
        # The test already verifies this, but we can add additional checks
        echo "Cache performance tests completed"