.github/workflows/primer_comment.yaml

# Most of this is inspired by the mypy primer
# See: https://github.com/hauntsaninja/mypy_primer
# This is the primer job that creates the comment on the PR
# It needs to trigger on workflow_run instead of pull_request
# as we need repository wide access to create a comment

name: Primer / Comment

on:
  workflow_run:
    workflows: [Primer / Run]
    types:
      - completed

env:
  # This needs to be the SAME as in the Main and PR job
  CACHE_VERSION: 31

permissions:
  contents: read
  pull-requests: write

jobs:
  primer-comment:
    # Skip job if the workflow failed
    if: ${{ github.event.workflow_run.conclusion == 'success' }}
    name: Run
    runs-on: ubuntu-latest
    steps:
      - uses: actions/setup-node@v3
        with:
          node-version: 16
      - run: npm install @octokit/rest
      - name: Check out code from GitHub
        uses: actions/checkout@v3.0.2
      - name: Set up Python 3.10
        id: python
        uses: actions/setup-python@v4.2.0
        with:
          python-version: "3.10"

      # Restore cached Python environment
      - name: Restore Python virtual environment
        id: cache-venv
        uses: actions/cache@v3.0.8
        with:
          path: venv
          key:
            ${{ runner.os }}-${{ steps.python.outputs.python-version }}-venv-primer-${{
            env.CACHE_VERSION }}
      - name: Fail job if Python cache restore failed
        if: steps.cache-venv.outputs.cache-hit != 'true'
        run: |
          echo "Failed to restore Python venv from cache"
          exit 1

      - name: Download outputs
        uses: actions/github-script@v6
        with:
          script: |
            // Download workflow pylint output
            const fs = require('fs');
            const artifacts_workflow = await github.rest.actions.listWorkflowRunArtifacts({
               owner: context.repo.owner,
               repo: context.repo.repo,
               run_id: ${{ github.event.workflow_run.id }},
            });

            // Get 'main' output
            const [matchArtifactWorkflowMain] = artifacts_workflow.data.artifacts.filter((artifact) =>
              artifact.name == "primer_output_main");
            const downloadOne = await github.rest.actions.downloadArtifact({
               owner: context.repo.owner,
               repo: context.repo.repo,
               artifact_id: matchArtifactWorkflowMain.id,
               archive_format: "zip",
            });
            fs.writeFileSync("primer_main_output.zip", Buffer.from(downloadOne.data));

            // Get PR output
            const [matchArtifactWorkflowPR] = artifacts_workflow.data.artifacts.filter((artifact) =>
              artifact.name == "primer_output_pr");
            const downloadTwo = await github.rest.actions.downloadArtifact({
               owner: context.repo.owner,
               repo: context.repo.repo,
               artifact_id: matchArtifactWorkflowPR.id,
               archive_format: "zip",
            });
            fs.writeFileSync("primer_pr_output.zip", Buffer.from(downloadTwo.data));

            // Get PR number
            const [matchArtifactWorkflowNumber] = artifacts_workflow.data.artifacts.filter((artifact) =>
              artifact.name == "pr_number");
            const downloadThree = await github.rest.actions.downloadArtifact({
               owner: context.repo.owner,
               repo: context.repo.repo,
               artifact_id: matchArtifactWorkflowNumber.id,
               archive_format: "zip",
            });
            fs.writeFileSync("primer_pr_number.zip", Buffer.from(downloadThree.data));
      - run: unzip primer_main_output.zip
      - run: unzip primer_pr_output.zip
      - run: unzip primer_pr_number.zip
      - name: Compare outputs
        run: |
          . venv/bin/activate
          python tests/primer/__main__.py compare \
          --commit=${{ github.event.workflow_run.head_sha }} \
          --base-file=output_${{ steps.python.outputs.python-version }}_main.txt \
          --new-file=output_${{ steps.python.outputs.python-version }}_pr.txt
      - name: Post comment
        id: post-comment
        uses: actions/github-script@v6
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const fs = require('fs')
            const comment = fs.readFileSync('tests/.pylint_primer_tests/comment.txt', { encoding: 'utf8' })
            console.log("Comment to post:")
            console.log(comment)
            const prNumber = parseInt(fs.readFileSync("pr_number.txt", { encoding: "utf8" }))
            await github.rest.issues.createComment({
              issue_number: prNumber,
              owner: context.repo.owner,
              repo: context.repo.repo,
              body: comment
            })
            return prNumber
      - name: Hide old comments
        # Taken from mypy primer
        # v0.3.0
        uses: kanga333/comment-hider@bbdf5b562fbec24e6f60572d8f712017428b92e0
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          leave_visible: 1
          issue_number: ${{ steps.post-comment.outputs.result }}