Fixed #36639 -- Added CI step to run makemigrations --check against test models.

.github/workflows/check-migrations.yml

@@ -0,0 +1,68 @@
+name: Check migrations
+
+on:
+  pull_request:
+    paths:
+      - 'tests/**/models.py'
+      - 'tests/**/migrations/**'
+      - 'tests/**/*migrations/**/*.py'
+      - 'scripts/check_migrations.py'
+  push:
+    branches:
+      - main
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  check-migrations:
+    name: Check test migrations
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+
+    services:
+      postgres:
+        image: postgres:15-alpine
+        env:
+          POSTGRES_DB: django
+          POSTGRES_USER: user
+          POSTGRES_PASSWORD: postgres
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+
+      - name: Set up Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: '3.14'
+          cache: 'pip'
+          cache-dependency-path: 'tests/requirements/py3.txt'
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip wheel
+          python -m pip install -e . psycopg[binary]
+
+      - name: Create PostgreSQL settings file
+        run: mv ./.github/workflows/data/test_postgres.py.tpl ./tests/test_postgres.py
+
+      - name: Check for missing migrations
+        env:
+          DJANGO_SETTINGS_MODULE: test_postgres
+          PYTHONPATH: ${{ github.workspace }}/tests:${{ github.workspace }}
+        run: |
+          python scripts/check_migrations.py

scripts/check_migrations.py

@@ -0,0 +1,31 @@
+import sys
+from pathlib import Path
+
+
+def main():
+    repo_root = Path(__file__).resolve().parent.parent
+    sys.path[:0] = [str(repo_root / "tests"), str(repo_root)]
+
+    from runtests import ALWAYS_INSTALLED_APPS, get_apps_to_install, get_test_modules
+
+    import django
+    from django.apps import apps
+    from django.core.management import call_command
+
+    django.setup()
+
+    test_modules = list(get_test_modules(gis_enabled=False))
+    installed_apps = list(ALWAYS_INSTALLED_APPS)
+    for app in get_apps_to_install(test_modules):
+        # Check against the list to prevent duplicate errors.
+        if app not in installed_apps:
+            installed_apps.append(app)
+    apps.set_installed_apps(installed_apps)
+
+    # Note: We don't use check=True here because --check calls sys.exit(1)
+    # instead of raising CommandError when migrations are missing.
+    call_command("makemigrations", "--check", verbosity=3)
+
+
+if __name__ == "__main__":
+    main()