Tested altering a unique field when a reverse M2M relation exists.

This commit is contained in:
Jeremy Bowman 2018-04-11 10:19:09 -04:00 committed by Tim Graham
parent 99539ca319
commit 003334f8af
1 changed files with 37 additions and 1 deletions

View File

@ -22,7 +22,7 @@ from django.db.transaction import TransactionManagementError, atomic
from django.test import (
TransactionTestCase, skipIfDBFeature, skipUnlessDBFeature,
)
from django.test.utils import CaptureQueriesContext, isolate_apps
from django.test.utils import CaptureQueriesContext, isolate_apps, patch_logger
from django.utils import timezone
from .fields import (
@ -1545,6 +1545,42 @@ class SchemaTests(TransactionTestCase):
TagUniqueRename.objects.create(title="bar", slug2="foo")
Tag.objects.all().delete()
@isolate_apps('schema')
@unittest.skipIf(connection.vendor == 'sqlite', 'SQLite remakes the table on field alteration.')
def test_unique_and_reverse_m2m(self):
"""
AlterField can modify a unique field when there's a reverse M2M
relation on the model.
"""
class Tag(Model):
title = CharField(max_length=255)
slug = SlugField(unique=True)
class Meta:
app_label = 'schema'
class Book(Model):
tags = ManyToManyField(Tag, related_name='books')
class Meta:
app_label = 'schema'
with connection.schema_editor() as editor:
editor.create_model(Tag)
editor.create_model(Book)
new_field = SlugField(max_length=75, unique=True)
new_field.model = Tag
new_field.set_attributes_from_name('slug')
with patch_logger('django.db.backends.schema', 'debug') as logger_calls:
with connection.schema_editor() as editor:
editor.alter_field(Tag, Tag._meta.get_field('slug'), new_field)
# One SQL statement is executed to alter the field.
self.assertEqual(len(logger_calls), 1)
# Ensure that the field is still unique.
Tag.objects.create(title='foo', slug='foo')
with self.assertRaises(IntegrityError):
Tag.objects.create(title='bar', slug='foo')
def test_unique_together(self):
"""
Tests removing and adding unique_together constraints on a model.