pr-percy-snapshots.yml

# This workflow listens for completion of the `pr-percy-prepare` workflows, picks up their outputs, and performs Percy testing.
name: "Percy screenshots"

on:
  workflow_run:
    workflows:
      - "Percy (pushed)"
      - "Percy (labeled)"
    types:
      - completed

jobs:
  upload:
    name: Build project with proposed changes & take Percy snapshots
    if: github.event.workflow_run.conclusion=='success'
    runs-on: ubuntu-latest
    outputs:
      pr_head_sha: ${{ steps.get_pr_data.outputs.sha }}
      pr_number: ${{ steps.get_pr_data.outputs.pr_number }}
      percy_build_link: ${{ steps.percy_snapshot.outputs.build_link }}
      percy_org_id: ${{ steps.percy_snapshot.outputs.org_id }}
      percy_build_id: ${{ steps.percy_snapshot.outputs.build_id }}
    steps:
      # Checkout `main` branch of Vanilla
      - name: Checkout SCM
        uses: actions/checkout@v4

      - name: Remove SCM directories that will be replaced by artifact files
        run: rm -rf templates/docs/examples/ templates/_macros/ tokens/ sd.config.json scss/

      - name: Download artifact from prepare workflow
        uses: actions/download-artifact@v4
        with:
          name: "percy-testing-web-artifact"
          github-token: ${{ secrets.GITHUB_TOKEN }}
          repository: ${{ github.event.workflow_run.repository.full_name }}
          run-id: ${{ github.event.workflow_run.id }}

      # Downloading the artifact in the previous step also extracts its contents into `./`.
      # However, there are some files in the artifact that are not in the same place as Vanilla expects them to be.
      # This step moves those files to the correct place.
      - name: Move artifact files into place to replace SCM
        run: |
          # ensure the examples & macros dirs exist for backwards compatibility in case they aren't in the PR artifact
          mkdir -p examples
          mkdir -p macros
          mkdir -p tokens
          # artifact directory contains `scss/`, `examples/`, `macros/`, 'tokens/', 'sd.config.json', `pr_num.txt`, and `pr_head_sha.txt`. 
          # `/examples` and `macros/` must be moved to `templates/`.
          mv examples/ templates/docs/.
          mv macros/ templates/_macros

      # The `pr_num.txt` and `pr_head_sha.txt` files are used to pass the PR number and head SHA from the PR to this workflow.
      # This is required as the `workflow_run` context of this workflow has no access to the context of the PR that triggered the `pr-percy-prepare` workflow.
      - name: Get PR data
        if: github.event.workflow_run.event=='pull_request'
        id: get_pr_data
        run: |
          echo "sha=$(cat pr_head_sha.txt)" >> $GITHUB_OUTPUT
          echo "pr_number=$(cat pr_num.txt)" >> $GITHUB_OUTPUT
          # Debugging step to show the full contents of the filesystem just before the Percy snapshot step
          tree

      # Composite action uses the filesystem we have prepared for it with this workflow
      - name: Build, run, and test Vanilla
        id: percy_snapshot
        uses: "./.github/actions/percy-snapshot"
        with:
          branch_name: "pull/${{ steps.get_pr_data.outputs.pr_number }}"
          pr_number: ${{ steps.get_pr_data.outputs.pr_number }}
          commitsh: ${{ steps.get_pr_data.outputs.sha }}
          percy_token_write: ${{ secrets.PERCY_TOKEN_WRITE }}