comment-perf.yml

name: "Post performance comparison comment on PR"

on:
  workflow_run:
    workflows: ["All tests"]
    types:
      - completed

# This is based off of the code snippets from:
# https://securitylab.github.com/research/github-actions-preventing-pwn-requests
jobs:
  post-perf-comparison:
    name: "Post performance comparison"
    runs-on: ubuntu-latest
    if: >
      ${{ github.event.workflow_run.event == 'pull_request' &&
      github.event.workflow_run.conclusion == 'success' }}
    steps:
      - name: 'Download artifact'
        uses: actions/github-script@v3.1.0
        with:
          script: |
            const artifacts = await github.actions.listWorkflowRunArtifacts({
               owner: context.repo.owner,
               repo: context.repo.repo,
               run_id: ${{github.event.workflow_run.id }},
            });
            const matchArtifact = artifacts.data.artifacts.filter((artifact) => {
              return artifact.name == "perf-comparison"
            })[0];
            const download = await github.actions.downloadArtifact({
               owner: context.repo.owner,
               repo: context.repo.repo,
               artifact_id: matchArtifact.id,
               archive_format: 'zip',
            });
            const fs = require('fs');
            fs.writeFileSync('${{github.workspace}}/perf-comparison.zip', Buffer.from(download.data));
      - run: unzip perf-comparison.zip

      - name: 'Comment on PR'
        uses: actions/github-script@v3.1.0
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const fs = require('fs');
            
            const prNumber = Number(fs.readFileSync('./pr-number.txt'));
            if (!prNumber) {
              return;
            }
            
            const summary = fs.readFileSync('./summary.txt').toString();
            
            const prComments = await github.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: prNumber,
            });
            
            const existingComment = prComments.data.find(
              (comment) => comment.body.includes("## Benchmark results")
            );
            
            if (existingComment) {
              await github.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existingComment.id,
                body: summary,
              });
            } else {
              await github.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: prNumber,
                body: summary,
              });
            }