element-web/.github/workflows/netlify.yaml

# Triggers after the layered build has finished, taking the artifact
# and uploading it to netlify
name: Upload Preview Build to Netlify
on:
  workflow_run:
    workflows: [ "Element Web - Build and Test" ]
    types:
      - completed
jobs:
  build:
    runs-on: ubuntu-latest
    if: >
      ${{ github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.event == 'pull_request' }}
    steps:
      - name: "🔍 Read PR number"
        id: readctx
        # we need to find the PR number that corresponds to the branch, which we do by
        # searching the GH API
        # The workflow_run event includes a list of pull requests, but it doesn't get populated for
        # forked PRs: https://docs.github.com/en/rest/reference/checks#create-a-check-run
        run: |
          head_branch='${{github.event.workflow_run.head_repository.owner.login}}:${{github.event.workflow_run.head_branch}}'
          echo "head branch: $head_branch"
          pulls_uri="https://api.github.com/repos/${{ github.repository }}/pulls?head=$(jq -Rr '@uri' <<<$head_branch)"
          pr_number=$(curl -s -H 'Authorization: Bearer ${{ secrets.GITHUB_TOKEN }}' "$pulls_uri" |
               jq -r '.[] | .number')
          echo "PR number: $pr_number"
          echo "::set-output name=prnumber::$pr_number"

      # There's a 'download artifact' action but it hasn't been updated for the
      # workflow_run action (https://github.com/actions/download-artifact/issues/60)
      # so instead we get this mess:
      - name: 'Download artifact'
        uses: actions/github-script@v3.1.0
        with:
          script: |
            var artifacts = await github.actions.listWorkflowRunArtifacts({
               owner: context.repo.owner,
               repo: context.repo.repo,
               run_id: ${{github.event.workflow_run.id }},
            });
            var matchArtifact = artifacts.data.artifacts.filter((artifact) => {
              return artifact.name == "previewbuild"
            })[0];
            var download = await github.actions.downloadArtifact({
               owner: context.repo.owner,
               repo: context.repo.repo,
               artifact_id: matchArtifact.id,
               archive_format: 'zip',
            });
            var fs = require('fs');
            fs.writeFileSync('${{github.workspace}}/previewbuild.zip', Buffer.from(download.data));

      - name: Extract Artifacts
        run: unzip -d webapp previewbuild.zip && rm previewbuild.zip

      - name: Deploy to Netlify
        id: netlify
        uses: nwtgck/actions-netlify@v1.2
        with:
          publish-dir: webapp
          deploy-message: "Deploy from GitHub Actions"
          # These don't work because we're in workflow_run
          enable-pull-request-comment: false
          enable-commit-comment: false
          alias: pr${{ steps.readctx.outputs.prnumber }}
        env:
          NETLIFY_AUTH_TOKEN: ${{ secrets.NETLIFY_AUTH_TOKEN }}
          NETLIFY_SITE_ID: ${{ secrets.NETLIFY_SITE_ID }}
        timeout-minutes: 1

      - name: Edit PR Description
        uses: Beakyn/gha-comment-pull-request@2167a7aee24f9e61ce76a23039f322e49a990409
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          pull-request-number: ${{ steps.readctx.outputs.prnumber }}
          description-message: |
            Preview: ${{ steps.netlify.outputs.deploy-url }}
            ⚠️ Do you trust the author of this PR? Maybe this build will steal your keys or give you malware. Exercise caution. Use test accounts.