Ticket #28861: 28861.diff

tests/schema/models.py

@@ -1 +1 @@
 from django.apps.registry import Apps
-from django.db import models
+from django.db import connection, models
 
 # Because we want to test creation and deletion of these as separate things,
 # these models are all inserted into a separate Apps so the main test
@@ -121 +121 @@
         apps = new_apps
 
 
+if connection.vendor == 'postgresql':
+    from django.contrib.postgres.fields import CICharField
+
+    class CIBookModel(models.Model):
+        title = CICharField(max_length=100, db_index=True)
+
+        class Meta:
+            apps = new_apps
+
+
 class IntegerPK(models.Model):
     i = models.IntegerField(primary_key=True)
     j = models.IntegerField(unique=True)

tests/schema/tests.py

@@ -2 +2 @@
 import itertools
 import unittest
 from copy import copy
-from unittest import mock
+from unittest import mock, skipUnless
 
 from django.db import (
     DatabaseError, IntegrityError, OperationalError, connection,
 )
+from django.db.migrations import Migration
+from django.db.migrations.state import ProjectState
 from django.db.models import Model
 from django.db.models.deletion import CASCADE, PROTECT
 from django.db.models.fields import (
@@ -22 +24 @@
 from django.test import (
     TransactionTestCase, skipIfDBFeature, skipUnlessDBFeature,
 )
-from django.test.utils import CaptureQueriesContext, isolate_apps
+from django.test.utils import (
+    CaptureQueriesContext, isolate_apps, modify_settings,
+)
 from django.utils import timezone
 
 from .fields import (
@@ -248 +252 @@
             editor.alter_field(AuthorCharFieldWithIndex, old_field, new_field, strict=True)
         self.assertForeignKeyExists(AuthorCharFieldWithIndex, 'char_field_id', 'schema_author')
 
+    @skipUnless(connection.vendor == 'postgresql', 'PostgreSQL specific tests for citext')
+    @modify_settings(INSTALLED_APPS={'append': 'django.contrib.postgres'})
+    def test_cichar_field_with_db_index_to_fk(self):
+        from django.contrib.postgres.operations import CITextExtension
+        from .models import CIBookModel
+        self.models.append(CIBookModel)
+        # Create the table and the necessary citext extension
+        migration = Migration('name', app_label='apps')
+        migration.operations = [CITextExtension()]
+        with connection.schema_editor() as editor:
+            editor.create_model(Book)
+            editor.create_model(Author)
+            migration.apply(ProjectState(), editor)
+            editor.create_model(CIBookModel)
+        # Change CICharField to FK
+        old_field = CIBookModel._meta.get_field('title')
+        new_field = ForeignKey(Book, CASCADE, blank=True)
+        new_field.set_attributes_from_name('title')
+        with connection.schema_editor() as editor:
+            editor.alter_field(CIBookModel, old_field, new_field, strict=True)
+        self.assertForeignKeyExists(CIBookModel, 'title_id', 'schema_book')
+
     @skipUnlessDBFeature('supports_foreign_keys')
     @skipUnlessDBFeature('supports_index_on_text_field')
     def test_text_field_with_db_index_to_fk(self):