check-dist.yml

# `dist/index.js` is a special file in Actions.
# When you reference an action with `uses:` in a workflow,
# `index.js` is the code that will run.
# For our project, we generate this file through a build process from other source files.
# We need to make sure the checked-in `index.js` actually matches what we expect it to be.
name: Check dist/

on:
  push:
    branches:
      - main
    paths-ignore:
      - '**.md'
  pull_request:
    paths-ignore:
      - '**.md'
  workflow_dispatch:

jobs:
  check-dist:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v7

      - name: Setup Node.js
        uses: actions/setup-node@v7.0.0
        with:
          node-version-file: package.json
          cache: npm

      - name: Install dependencies
        run: npm ci

      - name: Rebuild the dist/ directory
        run: npm run prepare

      - name: Compare the expected and actual dist/ directories
        run: |
          # `git diff` alone can't see files the build newly added, so check for
          # untracked files in dist/ too.
          untracked="$(git ls-files --others --exclude-standard -- dist/)"
          changed="$(git diff --ignore-space-at-eol -- dist/)"
          if [ -n "$untracked" ] || [ -n "$changed" ]; then
            echo "Detected uncommitted changes after build.  See status below:"
            if [ -n "$untracked" ]; then
              printf 'Untracked files in dist/:\n%s\n' "$untracked"
            fi
            git diff -- dist/
            exit 1
          fi
        id: diff

      # If index.js was different than expected, upload the expected version as an artifact
      - uses: actions/upload-artifact@v7
        if: ${{ failure() && steps.diff.conclusion == 'failure' }}
        with:
          name: dist
          path: dist/