pr-check-changeset.yml

name: "pr-check-changeset"

# This workflow checks PRs for the presence of a new changeset file. When a PR is opened, it will be checked for a
# changeset. The results of the check are uploaded as a pipeline artifact. After this workflow is completed it triggers
# the changeset-reporter workflow, which adds a comment to the PR depending on the results of the check.
#
# The workflows are separated for security reasons. This workflow does not require write access to the repo, but the
# changeset-reporter workflow does.

on:
  pull_request:
    types: [labeled, unlabeled, opened, synchronize, reopened]

permissions:
  pull-requests: read

jobs:
  # When a PR has the changeset-required label, check if it has a changeset.
  changeset-required:
    name: Changeset required
    runs-on: ubuntu-latest
    if: contains(github.event.pull_request.labels.*.name, 'changeset-required')
    steps:
      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # ratchet:actions/checkout@v3
        with:
          fetch-depth: "0" # all history
          persist-credentials: false
          ref: ${{ github.event.pull_request.head.sha }} # Check out the head commit, not the merge commit

      # install and configure node, pnpm and the changeset tools
      - uses: pnpm/action-setup@fe02b34f77f8bc703788d5817da081398fad5dd2 # ratchet:pnpm/action-setup@v4
      - uses: actions/setup-node@1a4442cacd436585916779262731d5b162bc6ec7 # ratchet:actions/setup-node@v3
        with:
          node-version-file: .nvmrc
          cache: "pnpm"
          cache-dependency-path: pnpm-lock.yaml
      - name: Install tools
        run: |
          # We only need to install the root dependencies
          pnpm install -w --frozen-lockfile

      # Add the remote in forked repos so we can more easily test in forks
      - run: git remote add upstream https://github.com/microsoft/FluidFramework
        if: github.repository_owner != 'microsoft'
      - run: git fetch upstream
        if: github.repository_owner != 'microsoft'
      - run: git log -1
        if: github.repository_owner != 'microsoft'

      # Check whether a changeset was added. This step will have the outcome '1' if there is no changeset.
      - name: Changeset metadata
        run: |
          # JSON output is piped through jq to compact it to a single line
          pnpm exec flub check changeset --branch=${{ github.base_ref }} --json | jq -c > changeset-metadata.json

      # We save the PR number because downstream pipelines are triggered by workflow_run, and the PR number is not easily
      # retrievable in such workflows
      - name: Add PR number to metadata
        run: |
          echo $(jq -c '. += { pr: "${{ github.event.number }}" }' changeset-metadata.json) > changeset-metadata.json

      # Sets required = true/false based on the changeset-required label on the PR
      - name: Changeset required
        if: contains(github.event.pull_request.labels.*.name, 'changeset-required')
        run: |
          echo $(jq -c '. += {required: true}' changeset-metadata.json) > changeset-metadata.json

      - name: Changeset not required
        if: ${{ !contains(github.event.pull_request.labels.*.name, 'changeset-required') }}
        run: |
          echo $(jq -c '. += {required: false}' changeset-metadata.json) > changeset-metadata.json

      - name: Upload changeset metadata
        uses: actions/upload-artifact@a8a3f3ad30e3422c9c7b888a15615d19a852ae32 # ratchet:actions/upload-artifact@v3
        with:
          name: changeset-metadata
          path: ./changeset-metadata.json
          retention-days: 3

  # Any PR without the changeset-required label will be ignored.
  changeset-not-required:
    name: Changeset not required
    runs-on: ubuntu-latest
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'changeset-required') }}
    steps:
      # Always output changesetFound = true and required = false to signal that changesets aren't needed. changesetFound
      # must be set because it's not nullable.
      - name: Changeset metadata
        run: |
          echo "{\"branch\": \"${{ github.base_ref }}\", \"required\": false, \"changesetFound\": true}" > ./changeset-metadata.json

      # We save the PR number because downstream pipelines are triggered by workflow_run, and the PR number is not easily
      # retrievable in such workflows
      - name: Add PR number to metadata
        run: |
          echo $(jq -c '. += { pr: "${{ github.event.number }}" }' changeset-metadata.json) > changeset-metadata.json

      - name: Upload changeset metadata
        uses: actions/upload-artifact@a8a3f3ad30e3422c9c7b888a15615d19a852ae32 # ratchet:actions/upload-artifact@v3
        with:
          name: changeset-metadata
          path: ./changeset-metadata.json
          retention-days: 3