action.yml

name: 'Go Benchmark Action'
description: 'Run Go benchmarks and optionally publish results to GitHub Pages'
inputs:
  benchmarks-pr:
    description: 'Comma-separated list of benchmarks to run on PRs (e.g., BenchmarkOne, BenchmarkTwo). Set to "from-pr" to extract from PR description.'
    required: false
    default: 'from-pr'

  benchmarks-merge:
    description: 'Comma-separated list of benchmarks to run on merges (e.g., BenchmarkOne, BenchmarkTwo).'
    required: false
    default: ''

  trigger-branches:
    # if this input did not exist, every commit to every branch (including PRs) will trigger the action for merges,
    # this is because both PRs and pushes to branches trigger the 'push' event
    description: 'Comma-separated list of branches for which merges will trigger this action.'
    required: true

  use-gh-pages:
    description: 'Flag to enable publishing results to GitHub Pages (true or false)'
    required: false
    default: false

  github-token:
    description: 'GitHub token for authentication (GITHUB_TOKEN or a personal access token). Required if use-gh-pages is true.'
    required: false

  gh-pages-branch:
    description: 'The GitHub Pages branch to push results to (defaults to gh-pages). Required if use-gh-pages is true.'
    required: false
    default: 'gh-pages'

  alert-comment-cc-users:
    description: 'Comma-separated list of users to cc on alert comments (e.g., @user1, @user2).'
    required: false
    default: ''

runs:
  using: 'composite'
  steps:
    - name: Checkout Code
      uses: actions/checkout@v3

    - name: Setup Go Environment
      uses: actions/setup-go@v4
      with:
        go-version: 'stable'

    - name: Analyze GitHub Event
      id: analyze-event
      run: |
        if [[ "${{ github.event_name }}" == "pull_request" ]]; then
          echo "IS_MERGE=false" >> $GITHUB_ENV
          echo "IS_PR=true" >> $GITHUB_ENV
        elif [[ "${{ github.event_name }}" == "push" ]]; then
          TRIGGER_BRANCHES="${{ inputs.trigger-branches }}"
          if [[ "$TRIGGER_BRANCHES" == *"${{ github.ref_name }}"* ]]; then
            echo "IS_MERGE=true" >> $GITHUB_ENV
            echo "IS_PR=false" >> $GITHUB_ENV
          else
            echo "IS_MERGE=false" >> $GITHUB_ENV
            echo "IS_PR=false" >> $GITHUB_ENV
          fi
        else
          echo "IS_MERGE=false" >> $GITHUB_ENV
          echo "IS_PR=false" >> $GITHUB_ENV
        fi
      shell: bash

    - name: Determine Benchmarks to Run
      id: set-benchmarks
      run: |
        if [[ "${{ inputs.benchmarks-pr }}" == "from-pr" && ${{ env.IS_PR }} == "true" ]]; then
          BENCHMARKS=$(echo '${{ github.event.pull_request.body }}' | sed -n -e 's/^.*BENCHMARKS: //p')
        else
          BENCHMARKS=${{ inputs.benchmarks-merge }}
        fi
        echo "BENCHMARKS=$BENCHMARKS" >> $GITHUB_ENV
      shell: bash

    - name: Run Specified Go Benchmarks
      # must use a context in an if conditional statement to access the value of an variable
      if: ${{ env.IS_PR == 'true' || env.IS_MERGE == 'true' }}
      run: go test ./... -bench "$BENCHMARKS" -run=^$ | tee output.txt
      shell: bash

    - name: Download Previous Benchmark Data
      if: ${{ env.IS_PR == 'true' || env.IS_MERGE == 'true' }}
      uses: actions/cache@v2
      with:
        path: ./cache
        key: ${{ runner.os }}-benchmark

    - name: Run github-action-benchmark for PRs
      if: ${{ env.IS_PR == 'true' }}
      uses: benchmark-action/github-action-benchmark@v1
      with:
        tool: 'go'
        output-file-path: output.txt
        external-data-json-path: './cache/benchmark-data.json'
        fail-on-alert: true
        auto-push: false
        comment-on-alert: true
        summary-always: true
        github-token: ${{ inputs.github-token }}

    - name: Run github-action-benchmark for Merges
      if: ${{ env.IS_MERGE == 'true' }}
      uses: benchmark-action/github-action-benchmark@v1
      with:
        tool: 'go'
        output-file-path: output.txt
        fail-on-alert: false
        comment-on-alert: true
        auto-push: ${{ inputs.use-gh-pages == 'true' }}
        github-token: ${{ inputs.github-token }}
        alert-comment-cc-users: ${{ inputs.alert-comment-cc-users }}

    - name: Upload Updated Benchmark Data
      if: ${{ env.IS_MERGE == 'true' }}
      uses: actions/cache@v2
      with:
        path: ./cache
        key: ${{ runner.os }}-benchmark
        restore-keys: ${{ runner.os }}-benchmark