Random fixes (#60)

.github/workflows/_tests.yml

@@ -60,6 +60,11 @@ jobs:
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python-version }}
+      - name: Cache pip
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-py-${{ matrix.python-version }}-dj-${{ matrix.django-version }}
       - name: Install prerequisites
         run: |
           DJANGO="django==${{ matrix.django-version }}"

django_squash/db/migrations/autodetector.py

@@ -11,12 +11,17 @@
 
 from . import operators, utils
 
+RESERVED_MIGRATION_KEYWORDS = ("_deleted", "_dependencies_change", "_replaces_change", "_original_migration")
+
 
 class Migration(dj_migrations.Migration):
 
-    _deleted = False
-    _dependencies_change = False
-    _replaces_change = False
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._deleted = False
+        self._dependencies_change = False
+        self._replaces_change = False
+        self._original_migration = None
 
     def describe(self):
         if self._deleted:
@@ -38,8 +43,17 @@ def __iter__(self):
 
     @classmethod
     def from_migration(cls, migration):
-        new = Migration(name=migration.name, app_label=migration.app_label)
-        new.__dict__ = migration.__dict__.copy()
+        if cls in type(migration).mro():
+            return migration
+
+        for keyword in RESERVED_MIGRATION_KEYWORDS:
+            if hasattr(migration, keyword):
+                raise RuntimeError(
+                    'Cannot use keyword "%s" in Migration %s.%s' % (keyword, migration.app_label, migration.name)
+                )
+
+        new = cls(name=migration.name, app_label=migration.app_label)
+        new.__dict__.update(migration.__dict__)
         new._original_migration = migration
         return new
 
@@ -129,7 +143,7 @@ def rename_migrations(self, original, graph, changes, migration_name):
                     migration_name or "squashed",
                 )
 
-    def convert_migration_references_to_objects(self, original, graph, changes):
+    def convert_migration_references_to_objects(self, original, changes, ignore_apps):
         """
         Swap django.db.migrations.Migration with a custom one that behaves like a tuple when read, but is still an
         object for the purpose of easy renames.
@@ -190,7 +204,7 @@ def create_deleted_models_migrations(self, loader, changes):
             instance.replaces = migrations
             changes[app_label] = [instance]
 
-    def squash(self, real_loader, squash_loader, ignore_apps=None, migration_name=None):
+    def squash(self, real_loader, squash_loader, ignore_apps, migration_name=None):
         changes_ = self.delete_old_squashed(real_loader, ignore_apps)
 
         graph = squash_loader.graph
@@ -200,7 +214,7 @@ def squash(self, real_loader, squash_loader, ignore_apps=None, migration_name=No
             changes.pop(app, None)
 
         self.create_deleted_models_migrations(real_loader, changes)
-        self.convert_migration_references_to_objects(real_loader, graph, changes)
+        self.convert_migration_references_to_objects(real_loader, changes, ignore_apps)
         self.rename_migrations(real_loader, graph, changes, migration_name)
         self.replace_current_migrations(real_loader, graph, changes)
         self.add_non_elidables(real_loader, squash_loader, changes)

setup.cfg

@@ -27,8 +27,9 @@ repository=https://upload.pypi.org/legacy/
 username=kingbuzzman
 
 [tool:pytest]
-pythonpath=tests
 DJANGO_SETTINGS_MODULE=settings
+pythonpath=tests
+addopts="--pdbcls=IPython.terminal.debugger:TerminalPdb"
 python_files=test_*.py *_tests.py
 markers=
     temporary_migration_module
@@ -45,3 +46,6 @@ filterwarnings=
 
     # Warning: cgi is only being used by Django 3.2
     ignore:'cgi' is deprecated and slated for removal in Python 3.13
+
+    # Django 3.2 throws a warning about the USE_I18N setting being deprecated
+    ignore:datetime.datetime.utcnow\(\) is deprecated and scheduled for removal in a future version. Use timezone-aware objects .*

tests/conftest.py

@@ -9,6 +9,7 @@
 
 import pytest
 from django.core.management import call_command
+from django.db import connections
 from django.db.models.options import Options
 from django.test.utils import extend_sys_path
 from django.utils.module_loading import module_dir
@@ -146,3 +147,28 @@ def _call_squash_migrations(*args, **kwargs):
         call_command("squash_migrations", *args, **kwargs)
 
     yield _call_squash_migrations
+
+
+@pytest.fixture
+def clean_db(django_db_blocker):
+    """
+    Clean the database after each test. As in a new database.
+
+    Usage:
+
+        @pytest.mark.usefixtures("clean_db")
+        @pytest.mark.django_db(transaction=True)
+        def test_something():
+            ...
+    """
+    with django_db_blocker.unblock():
+        # Because we're using an in memory sqlite database, we can just reset the connection
+        # When the connection is reestablished, the database will be empty
+        connections["default"].connection.close()
+        del connections["default"]
+
+        with connections["default"].cursor() as c:
+            # make sure the database is of any tables
+            assert connections["default"].introspection.get_table_list(c) == []
+
+        yield

tests/test_migrations_autodetector.py

@@ -0,0 +1,85 @@
+import pytest
+from django.db.migrations import Migration as OriginalMigration
+
+from django_squash.db.migrations import autodetector, operators, utils
+
+
+def test_migration():
+    original = OriginalMigration("0001_inital", "app")
+    new = autodetector.Migration.from_migration(original)
+    assert new.name == "0001_inital"
+    assert new.app_label == "app"
+    assert new._original_migration == original
+
+    assert new[0] == "app"
+    assert new[1] == "0001_inital"
+    assert list(new) == ["app", "0001_inital"]
+
+    assert not list(new.describe())
+    assert not new.is_migration_level
+    new._deleted = True
+    new._dependencies_change = True
+    new._replaces_change = True
+    assert new.is_migration_level
+    assert list(new.describe()) == ["Deleted", '"dependencies" changed', '"replaces" keyword removed']
+
+
+def test_migration_using_keywords():
+    """
+    Test that the migration can be created using our internal keywords
+    """
+
+    class FakeMigration:
+        app_label = "app"
+        name = "0001_inital"
+
+    autodetector.Migration.from_migration(FakeMigration())
+
+    for keyword in autodetector.RESERVED_MIGRATION_KEYWORDS:
+        migration = OriginalMigration("0001_inital", "app")
+        fake_migration = FakeMigration()
+        new_migration = autodetector.Migration("0001_inital", "app")
+
+        setattr(migration, keyword, True)
+        setattr(fake_migration, keyword, True)
+        setattr(new_migration, keyword, True)
+
+        with pytest.raises(RuntimeError):
+            autodetector.Migration.from_migration(migration)
+
+        with pytest.raises(RuntimeError):
+            autodetector.Migration.from_migration(fake_migration)
+
+        autodetector.Migration.from_migration(new_migration)
+
+
+def noop(*a, **k):
+    pass
+
+
+def test_all_custom_operations():
+    """
+    Test that all_custom_operations returns the correct operations
+    """
+    var = utils.UniqueVariableName()
+
+    class Migration(autodetector.Migration):
+        operations = [
+            operators.RunSQL("SELECT 1", elidable=True),
+            operators.RunPython(noop, elidable=True),
+            operators.RunSQL("SELECT 2", elidable=True),
+        ]
+
+    assert list(autodetector.all_custom_operations(Migration.operations, var)) == []
+
+    class Migration(autodetector.Migration):
+        operations = [
+            operators.RunSQL("SELECT 1", elidable=False),
+            operators.RunPython(noop, elidable=False),
+            operators.RunSQL("SELECT 2", elidable=True),
+        ]
+
+    assert [type(x).__name__ for x in autodetector.all_custom_operations(Migration.operations, var)] == [
+        "RunSQL",
+        "RunPython",
+    ]