bench.yml

name: Benchmarks

# Publish-only: runs benchmarks, pushes results to the gh-pages branch where
# benchmark-action renders a chart. Never gates a PR merge. Annotates points
# that regressed by 50%+ but does not fail the workflow.

on:
  push:
    branches: [main]
  schedule:
    - cron: '0 6 * * *'    # daily at 06:00 UTC
  workflow_dispatch:

# Needed by benchmark-action to push to gh-pages.
permissions:
  contents: write
  deployments: write

jobs:
  bench:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: actions/setup-go@v5
        with:
          go-version: '1.23'

      # -count=5 averages over five runs to dampen shared-runner noise.
      # -run='^$' skips tests so only benchmarks execute.
      - name: Run benchmarks
        run: |
          go test -bench=. -benchmem -count=5 -run='^$' \
            ./tests/benchmarks/... | tee output.txt

      - name: Publish chart
        uses: benchmark-action/github-action-benchmark@v1
        with:
          tool: 'go'
          output-file-path: output.txt
          github-token: ${{ secrets.GITHUB_TOKEN }}
          gh-pages-branch: gh-pages
          benchmark-data-dir-path: 'dev/bench'
          auto-push: true
          # Annotate 1.5x regressions but never fail or comment.
          alert-threshold: '150%'
          fail-on-alert: false
          comment-on-alert: false
          summary-always: true