Add tests for the makemigrations override

tests/functional/test_makemigrations_command.py

@@ -0,0 +1,195 @@
+import io
+import os
+import shutil
+import sys
+import tempfile
+from contextlib import contextmanager
+from importlib import import_module
+
+if sys.version_info >= (3, 3):
+    import unittest.mock as mock
+else:
+    import mock
+
+from django.apps import apps
+from django.conf import settings
+from django.core.management import call_command
+from django.test import TransactionTestCase
+from django.test.utils import extend_sys_path, override_settings
+from django.utils.module_loading import module_dir
+
+MAKEMIGRATIONS_INSTALLED_APPS = settings.INSTALLED_APPS + [
+    "tests.test_project.makemigrations_correct_migration_missing",
+    "tests.test_project.makemigrations_backward_incompatible_migration_missing",
+]
+
+
+@override_settings(INSTALLED_APPS=MAKEMIGRATIONS_INSTALLED_APPS)
+class BaseMakeMigrationsTestCase(TransactionTestCase):
+    @contextmanager
+    def temporary_migration_module(self, app_label="migrations", module=None):
+        """
+        Shamelessly copied from Django.
+        See django.tests.migrations.test_base.MigrationTestBase.temporary_migration_module
+
+        Allows testing management commands in a temporary migrations module.
+
+        Wrap all invocations to makemigrations and squashmigrations with this
+        context manager in order to avoid creating migration files in your
+        source tree inadvertently.
+        """
+        with tempfile.TemporaryDirectory() as temp_dir:
+            target_dir = tempfile.mkdtemp(dir=temp_dir)
+            with open(os.path.join(target_dir, "__init__.py"), "w"):
+                pass
+            target_migrations_dir = os.path.join(target_dir, "migrations")
+
+            if module is None:
+                module = apps.get_app_config(app_label).name + ".migrations"
+
+            try:
+                source_migrations_dir = module_dir(import_module(module))
+            except (ImportError, ValueError):
+                pass
+            else:
+                shutil.copytree(source_migrations_dir, target_migrations_dir)
+
+            with extend_sys_path(temp_dir):
+                new_module = os.path.basename(target_dir) + ".migrations"
+                with self.settings(MIGRATION_MODULES={app_label: new_module}):
+                    yield target_migrations_dir
+
+
+class MakeMigrationsCorrectTestCase(BaseMakeMigrationsTestCase):
+    available_apps = [
+        "django_migration_linter",
+        "tests.test_project.makemigrations_correct_migration_missing",
+    ]
+    databases = {"default", "postgresql"}
+
+    def test_correct_linted_makemigrations(self):
+        out = io.StringIO()
+        with self.temporary_migration_module(
+            app_label="makemigrations_correct_migration_missing"
+        ) as migration_dir:
+            call_command("makemigrations", lint=True, database="postgresql", stdout=out)
+            new_migration_file = os.path.join(migration_dir, "0002_a_new_field.py")
+            self.assertTrue(os.path.exists(new_migration_file))
+        output = out.getvalue()
+        self.assertIn("Linting for 'makemigrations_correct_migration_missing':", output)
+
+    @override_settings(MIGRATION_LINTER_OVERRIDE_MAKEMIGRATIONS=True)
+    def test_correct_linted_makemigrations_using_settings(self):
+        out = io.StringIO()
+        with self.temporary_migration_module(
+            app_label="makemigrations_correct_migration_missing"
+        ) as migration_dir:
+            call_command("makemigrations", database="postgresql", stdout=out)
+            new_migration_file = os.path.join(migration_dir, "0002_a_new_field.py")
+            self.assertTrue(os.path.exists(new_migration_file))
+        output = out.getvalue()
+        self.assertIn("Linting for 'makemigrations_correct_migration_missing':", output)
+
+    def test_no_linting_when_no_option(self):
+        out = io.StringIO()
+        with self.temporary_migration_module(
+            app_label="makemigrations_correct_migration_missing"
+        ) as migration_dir:
+            call_command("makemigrations", database="postgresql", stdout=out)
+            new_migration_file = os.path.join(migration_dir, "0002_a_new_field.py")
+            self.assertTrue(os.path.exists(new_migration_file))
+        output = out.getvalue()
+        self.assertNotIn("Linting", output)
+
+    def test_correct_linted_makemigrations_dry_run(self):
+        out = io.StringIO()
+        with self.temporary_migration_module(
+            app_label="makemigrations_correct_migration_missing"
+        ) as migration_dir:
+            call_command(
+                "makemigrations",
+                lint=True,
+                database="postgresql",
+                dry_run=True,
+                stdout=out,
+            )
+            new_migration_file = os.path.join(migration_dir, "0002_a_new_field.py")
+            self.assertFalse(os.path.exists(new_migration_file))
+        output = out.getvalue()
+        self.assertNotIn("Linting", output)
+
+
+@override_settings(MIGRATION_LINTER_OVERRIDE_MAKEMIGRATIONS=True)
+class MakeMigrationsBackwardIncompatibleTestCase(BaseMakeMigrationsTestCase):
+    available_apps = [
+        "django_migration_linter",
+        "tests.test_project.makemigrations_backward_incompatible_migration_missing",
+    ]
+    databases = {"default", "sqlite", "mysql", "postgresql"}
+
+    def test_backward_incompatible_migration_postgresql(self):
+        out = io.StringIO()
+        with self.temporary_migration_module(
+            app_label="makemigrations_backward_incompatible_migration_missing"
+        ) as migration_dir:
+            call_command(
+                "makemigrations", interactive=False, database="postgresql", stdout=out
+            )
+            new_migration_file = os.path.join(migration_dir, "0002_a_new_field.py")
+            self.assertFalse(os.path.exists(new_migration_file))
+        output = out.getvalue()
+        self.assertIn("Deleted", output)
+
+    def test_backward_incompatible_migration_mysql(self):
+        out = io.StringIO()
+        with self.temporary_migration_module(
+            app_label="makemigrations_backward_incompatible_migration_missing"
+        ) as migration_dir:
+            call_command(
+                "makemigrations", interactive=False, database="mysql", stdout=out
+            )
+            new_migration_file = os.path.join(migration_dir, "0002_a_new_field.py")
+            self.assertFalse(os.path.exists(new_migration_file))
+        output = out.getvalue()
+        self.assertIn("Deleted", output)
+
+    def test_backward_incompatible_migration_sqlite(self):
+        out = io.StringIO()
+        with self.temporary_migration_module(
+            app_label="makemigrations_backward_incompatible_migration_missing"
+        ) as migration_dir:
+            call_command(
+                "makemigrations", interactive=False, database="sqlite", stdout=out
+            )
+            new_migration_file = os.path.join(migration_dir, "0002_a_new_field.py")
+            self.assertFalse(os.path.exists(new_migration_file))
+        output = out.getvalue()
+        self.assertIn("Deleted", output)
+
+    @mock.patch("builtins.input", return_value="yes")
+    def test_backward_incompatible_migration_interactive_keep_migration(self, *args):
+        out = io.StringIO()
+        with self.temporary_migration_module(
+            app_label="makemigrations_backward_incompatible_migration_missing"
+        ) as migration_dir:
+            call_command(
+                "makemigrations", interactive=True, database="postgresql", stdout=out
+            )
+            new_migration_file = os.path.join(migration_dir, "0002_a_new_field.py")
+            self.assertTrue(os.path.exists(new_migration_file))
+        output = out.getvalue()
+        self.assertNotIn("Deleted", output)
+
+    @mock.patch("builtins.input", return_value="no")
+    def test_backward_incompatible_migration_interactive_delete_migration(self, *args):
+        out = io.StringIO()
+        with self.temporary_migration_module(
+            app_label="makemigrations_backward_incompatible_migration_missing"
+        ) as migration_dir:
+            call_command(
+                "makemigrations", interactive=True, database="postgresql", stdout=out
+            )
+            new_migration_file = os.path.join(migration_dir, "0002_a_new_field.py")
+            self.assertFalse(os.path.exists(new_migration_file))
+        output = out.getvalue()
+        self.assertIn("Deleted", output)

tests/test_project/makemigrations_backward_incompatible_migration_missing/apps.py

@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class MakemigrationsBackwardIncompatibleMigrationMissingConfig(AppConfig):
+    name = "tests.test_project.makemigrations_backward_incompatible_migration_missing"

tests/test_project/makemigrations_backward_incompatible_migration_missing/migrations/0001_initial.py

@@ -0,0 +1,28 @@
+# Generated by Django 2.2 on 2020-06-26 17:49
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = []
+
+    operations = [
+        migrations.CreateModel(
+            name="A",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("x", models.IntegerField()),
+            ],
+        ),
+    ]

tests/test_project/makemigrations_backward_incompatible_migration_missing/models.py

@@ -0,0 +1,6 @@
+from django.db import models
+
+
+class A(models.Model):
+    x = models.IntegerField()
+    new_field = models.CharField(null=False, default="empty", max_length=255)

tests/test_project/makemigrations_correct_migration_missing/apps.py

@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class MakemigrationsCorrectMigrationMissingConfig(AppConfig):
+    name = "tests.test_project.makemigrations_correct_migration_missing"

tests/test_project/makemigrations_correct_migration_missing/migrations/0001_initial.py

@@ -0,0 +1,28 @@
+# Generated by Django 2.2 on 2020-06-26 15:57
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = []
+
+    operations = [
+        migrations.CreateModel(
+            name="A",
+            fields=[
+                (
+                    "id",
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("x", models.IntegerField()),
+            ],
+        ),
+    ]

tests/test_project/makemigrations_correct_migration_missing/models.py

@@ -0,0 +1,6 @@
+from django.db import models
+
+
+class A(models.Model):
+    x = models.IntegerField()
+    new_field = models.CharField(null=True, max_length=255)