Fixed #24442 -- Improved SchemaEditor's index name truncation.

1 files changed, 27 insertions, 3 deletions

diff --git a/tests/indexes/tests.py b/tests/indexes/tests.py
index 4bd2332674..3ef6d2939b 100644
--- a/tests/indexes/tests.py
+++ b/tests/indexes/tests.py
@@ -18,10 +18,34 @@ class SchemaIndexesTests(TestCase):
         with connection.schema_editor() as editor:
             index_name = editor._create_index_name(
                 model=Article,
-                column_names=("c1", "c2", "c3"),
+                column_names=("c1",),
                 suffix="123",
             )
-        self.assertEqual(index_name, "indexes_article_c1_7ce4cc86123")
+        self.assertEqual(index_name, "indexes_article_c1_a52bd80b123")
+
+    def test_index_name(self):
+        """
+        Index names on the built-in database backends::
+            * Are truncated as needed.
+            * Include all the column names.
+            * Include a deterministic hash.
+        """
+        long_name = 'l%sng' % ('o' * 100)
+        with connection.schema_editor() as editor:
+            index_name = editor._create_index_name(
+                model=Article,
+                column_names=('c1', 'c2', long_name),
+                suffix='ix',
+            )
+        expected = {
+            'mysql': 'indexes_article_c1_c2_looooooooooooooooooo_255179b2ix',
+            'oracle': 'indexes_a_c1_c2_loo_255179b2ix',
+            'postgresql': 'indexes_article_c1_c2_loooooooooooooooooo_255179b2ix',
+            'sqlite': 'indexes_article_c1_c2_l%sng_255179b2ix' % ('o' * 100),
+        }
+        if connection.vendor not in expected:
+            self.skipTest('This test is only supported on the built-in database backends.')
+        self.assertEqual(index_name, expected[connection.vendor])
 
     def test_index_together(self):
         editor = connection.schema_editor()
@@ -71,6 +95,6 @@ class SchemaIndexesTests(TestCase):
             self.skip("This test only applies to the InnoDB storage engine")
         index_sql = connection.schema_editor()._model_indexes_sql(ArticleTranslation)
         self.assertEqual(index_sql, [
-            'CREATE INDEX `indexes_articletranslation_99fb53c2` '
+            'CREATE INDEX `indexes_articletranslation_article_no_constraint_id_d6c0806b` '
             'ON `indexes_articletranslation` (`article_no_constraint_id`)'
         ])