Add (failing) tests cases for makeing a column not null with a Django default value

tests/fixtures.py

@@ -11,3 +11,5 @@ ALTER_COLUMN_DROP_NOT_NULL = "app_alter_column_drop_not_null"
 DROP_UNIQUE_TOGETHER = "app_unique_together"
 ADD_MANYTOMANY_FIELD = "app_add_manytomany_field"
 DATA_MIGRATIONS = "app_data_migrations"
+MAKE_NOT_NULL_WITH_DJANGO_DEFAULT = "app_make_not_null_with_django_default"
+MAKE_NOT_NULL_WITH_LIB_DEFAULT = "app_make_not_null_with_lib_default"

tests/functional/test_migration_linter.py

@@ -44,6 +44,14 @@ class BaseBackwardCompatibilityDetection(object):
         app = fixtures.ADD_NOT_NULL_COLUMN
         self._test_linter_finds_errors(app)
 
+    def test_detect_make_column_not_null_with_django_default(self):
+        app = fixtures.MAKE_NOT_NULL_WITH_DJANGO_DEFAULT
+        self._test_linter_finds_errors(app)
+
+    def test_detect_make_column_not_null_with_lib_default(self):
+        app = fixtures.MAKE_NOT_NULL_WITH_LIB_DEFAULT
+        self._test_linter_finds_no_errors(app)
+
     def test_detect_drop_column(self):
         app = fixtures.DROP_COLUMN
         self._test_linter_finds_errors(app)
@@ -97,6 +105,15 @@ class SqliteBackwardCompatibilityDetectionTestCase(
         app = fixtures.ADD_NOT_NULL_COLUMN_FOLLOWED_BY_DEFAULT
         self._test_linter_finds_errors(app)
 
+    def test_detect_make_column_not_null_with_django_default(self):
+        app = fixtures.MAKE_NOT_NULL_WITH_DJANGO_DEFAULT
+        self._test_linter_finds_errors(app)
+
+    def test_detect_make_column_not_null_with_lib_default(self):
+        # The 'django-add-default-value' doesn't handle sqlite correctly
+        app = fixtures.MAKE_NOT_NULL_WITH_LIB_DEFAULT
+        self._test_linter_finds_errors(app)
+
 
 class MySqlBackwardCompatibilityDetectionTestCase(
     BaseBackwardCompatibilityDetection, unittest.TestCase

tests/test_project/app_make_not_null_with_django_default/apps.py

@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class AppMakeNotNullWithDjangoDefaultConfig(AppConfig):
+    name = "app_make_not_null_with_django_default"

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

@@ -0,0 +1,28 @@
+# Generated by Django 2.2 on 2020-06-20 15:17
+
+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",
+                    ),
+                ),
+                ("col", models.CharField(max_length=10, null=True)),
+            ],
+        ),
+    ]

tests/test_project/app_make_not_null_with_django_default/migrations/0002_make_not_null_with_django_default.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2 on 2020-06-20 15:17
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("app_make_not_null_with_django_default", "0001_initial"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="a",
+            name="col",
+            field=models.CharField(default="empty", max_length=10),
+        ),
+    ]

tests/test_project/app_make_not_null_with_django_default/models.py

@@ -0,0 +1,5 @@
+from django.db import models
+
+
+class A(models.Model):
+    col = models.CharField(max_length=10, null=False, default="empty")

tests/test_project/app_make_not_null_with_lib_default/apps.py

@@ -0,0 +1,5 @@
+from django.apps import AppConfig
+
+
+class AppMakeNotNullWithLibDefaultConfig(AppConfig):
+    name = "app_make_not_null_with_lib_default"

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

@@ -0,0 +1,28 @@
+# Generated by Django 2.2 on 2020-06-20 15:23
+
+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",
+                    ),
+                ),
+                ("col", models.CharField(max_length=10, null=True)),
+            ],
+        ),
+    ]

tests/test_project/app_make_not_null_with_lib_default/migrations/0002_make_not_null_with_lib_default.py

@@ -0,0 +1,21 @@
+# Generated by Django 2.2 on 2020-06-20 15:23
+
+from django.db import migrations, models
+
+from django_add_default_value import AddDefaultValue
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("app_make_not_null_with_lib_default", "0001_initial"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="a",
+            name="col",
+            field=models.CharField(default="avalue", max_length=10),
+        ),
+        AddDefaultValue(model_name="a", name="col", value="avalue"),
+    ]

tests/test_project/app_make_not_null_with_lib_default/models.py

@@ -0,0 +1,5 @@
+from django.db import models
+
+
+class A(models.Model):
+    col = models.CharField(max_length=10, null=False, default="avalue")

tests/test_project/settings.py

@@ -54,6 +54,8 @@ INSTALLED_APPS = [
     "tests.test_project.app_rename_table",
     "tests.test_project.app_unique_together",
     "tests.test_project.app_data_migrations",
+    "tests.test_project.app_make_not_null_with_django_default",
+    "tests.test_project.app_make_not_null_with_lib_default",
 ]
 
 MIDDLEWARE = [

tests/unit/test_sql_analyser.py

@@ -64,6 +64,25 @@ class MySqlAnalyserTestCase(SqlAnalyserTestCase):
         ]
         self.assertValidSql(sql)
 
+    def test_make_column_not_null_with_django_default(self):
+        sql = [
+            "ALTER TABLE `app_drop_default_a` ALTER COLUMN `col` SET DEFAULT 'empty';",
+            "UPDATE `app_drop_default_a` SET `col` = 'empty' WHERE `col` IS NULL;",
+            "ALTER TABLE `app_drop_default_a` MODIFY `col` varchar(10) NOT NULL;",
+            "ALTER TABLE `app_drop_default_a` ALTER COLUMN `col` DROP DEFAULT;",
+        ]
+        self.assertBackwardIncompatibleSql(sql)
+
+    def test_make_column_not_null_with_lib_default(self):
+        sql = [
+            "ALTER TABLE `app_drop_default_a` ALTER COLUMN `col` SET DEFAULT 'empty';",
+            "UPDATE `app_drop_default_a` SET `col` = 'empty' WHERE `col` IS NULL;",
+            "ALTER TABLE `app_drop_default_a` MODIFY `col` varchar(10) NOT NULL;",
+            "ALTER TABLE `app_drop_default_a` ALTER COLUMN `col` DROP DEFAULT;",
+            "ALTER TABLE `app_drop_default_a` ALTER COLUMN `col` SET DEFAULT 'empty';",
+        ]
+        self.assertValidSql(sql)
+
 
 class SqliteAnalyserTestCase(SqlAnalyserTestCase):
     database_vendor = "sqlite"
@@ -165,3 +184,22 @@ class PostgresqlAnalyserTestCase(SqlAnalyserTestCase):
             'CREATE INDEX "app_add_manytomany_field_b_many_to_many_a_id_4b44832a" ON "app_add_manytomany_field_b_many_to_many"("a_id");',
         ]
         self.assertValidSql(sql)
+
+    def test_make_column_not_null_with_django_default(self):
+        sql = [
+            'ALTER TABLE "app_drop_default_a" ALTER COLUMN "col" SET DEFAULT \'empty\';',
+            'UPDATE "app_drop_default_a" SET "col" = \'empty\' WHERE "col" IS NULL;',
+            'ALTER TABLE "app_drop_default_a" ALTER COLUMN "col" SET NOT NULL;',
+            'ALTER TABLE "app_drop_default_a" ALTER COLUMN "col" DROP DEFAULT;',
+        ]
+        self.assertBackwardIncompatibleSql(sql)
+
+    def test_make_column_not_null_with_lib_default(self):
+        sql = [
+            'ALTER TABLE "app_drop_default_a" ALTER COLUMN "col" SET DEFAULT \'empty\';',
+            'UPDATE "app_drop_default_a" SET "col" = \'empty\' WHERE "col" IS NULL;',
+            'ALTER TABLE "app_drop_default_a" ALTER COLUMN "col" SET NOT NULL;',
+            'ALTER TABLE "app_drop_default_a" ALTER COLUMN "col" DROP DEFAULT;',
+            'ALTER TABLE "app_drop_default_a" ALTER COLUMN "col" SET DEFAULT `\'empty\';',
+        ]
+        self.assertValidSql(sql)