| 1 | | In current source code, in the **_unregister_lookup** method, [https://github.com/django/django/blame/main/django/db/models/query_utils.py#L212], the cache is not cleared, which should be done, as it is done in **register_lookup**, https://github.com/django/django/blame/main/django/db/models/query_utils.py#L202. |
| 2 | | Corresponding to this change, minor changes need to be brought in the **schema.tests.SchemaTests.test_func_unique_constraint_lookups** test. |
| | 1 | Hi Carlton. |
| | 2 | I have opened the PR https://github.com/django/django/pull/15569, and have also modified the test that was supposed to throw error(schema.tests.SchemaTests.test_func_unique_constraint_lookups). |
| | 3 | |
| | 4 | There is no test that checks if the lookup stays in cache after unregistering it. In my PR, I have added an assert statement to check it in **custom_lookups.tests.LookupTests.test_lookups_caching** test. Running the test without clearing cache from _unregister_lookup will fail. |
| | 5 | |
| | 6 | The cache stays between tests, so you are likely to get different results running tests independently and running all tests in a module. (PS: I faced this problem earlier running tests individually and together gave different results.) |