api-migration-check.yaml

name: API Migration Check

on:
  pull_request:
    branches:
      - main
      - develop
    paths:
      - 'migration/**'
      # The seed script and its data are actively maintained, not immutable schema migrations.
      - '!migration/seed/**'

permissions:
  contents: read

jobs:
  immutability:
    name: Migration immutability
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v5
        with:
          fetch-depth: 0

      - name: Block changes to existing migrations
        run: |
          git fetch origin ${{ github.base_ref }} --depth=100
          # Protect immutable schema migrations only; the seed script/data may change freely.
          CHANGED=$(git diff --name-status origin/${{ github.base_ref }}...HEAD -- migration/ ':(exclude)migration/seed/' \
                    | awk '$1 ~ /^[MDR]/ {print}')
          if [ -n "$CHANGED" ]; then
            echo "::error::Existing migrations must not be modified, renamed or deleted."
            echo ""
            echo "$CHANGED"
            echo ""
            echo "If a migration is wrong, add a follow-up migration instead of editing the old one."
            exit 1
          fi
          echo "No existing migrations were modified."