Drop django_mysql.utils.connection_is_mariadb (#913)

Author: adamchainz

HISTORY.rst

@@ -6,6 +6,13 @@ History
 
 * Support MariaDB 10.7.
 
+* Drop ``django_mysql.utils.connection_is_mariadb``. On Django 3.0+ you can
+  simply check:
+
+  .. code-block:: python
+
+      connection.vendor == "mysql" and connection.mysql_is_mariadb
+
 4.5.0 (2022-01-23)
 ------------------
 

docs/index.rst

@@ -28,7 +28,6 @@ action, or get started with :doc:`installation`. Otherwise, take your pick:
    locks
    status
    management_commands/index
-   utilities
    test_utilities
    exceptions
    contributing

docs/utilities.rst

@@ -24,7 +24,6 @@
 from django_mysql.checks import mysql_connections
 from django_mysql.models.lookups import DynColHasKey
 from django_mysql.typing import DeconstructResult
-from django_mysql.utils import connection_is_mariadb
 
 try:
     import mariadb_dyncol
@@ -102,7 +101,7 @@ def _check_mariadb_version(self) -> list[checks.CheckMessage]:
         errors = []
 
         any_conn_works = any(
-            (hasattr(conn, "mysql_version") and connection_is_mariadb(conn))
+            (conn.vendor == "mysql" and conn.mysql_is_mariadb)
             for _alias, conn in mysql_connections()
         )
 
@@ -122,9 +121,7 @@ def _check_character_set(self) -> list[checks.CheckMessage]:
 
         conn = None
         for _alias, check_conn in mysql_connections():
-            if hasattr(check_conn, "mysql_version") and connection_is_mariadb(
-                check_conn
-            ):
+            if check_conn.vendor == "mysql" and check_conn.mysql_is_mariadb:
                 conn = check_conn
                 break
 

src/django_mysql/models/fields/dynamic.py

@@ -11,8 +11,6 @@
 from django.db.models import Func, IntegerField, JSONField, TextField, Value
 from django.db.models.sql.compiler import SQLCompiler
 
-from django_mysql.utils import connection_is_mariadb
-
 ExpressionArgument = Union[
     Expression,
     str,  # column reference handled by Django
@@ -291,7 +289,7 @@ def as_sql(
         if connection.vendor != "mysql":  # pragma: no cover
             raise AssertionError("JSONValue only supports MySQL/MariaDB")
         json_string = json.dumps(self._data, allow_nan=False)
-        if connection_is_mariadb(connection):
+        if connection.vendor == "mysql" and connection.mysql_is_mariadb:
             # MariaDB doesn't support explicit cast to JSON.
             return "JSON_EXTRACT(%s, '$')", (json_string,)
         else:

src/django_mysql/models/functions.py

@@ -93,10 +93,6 @@ def format_duration(total_seconds: int) -> str:
     return "".join(out)
 
 
-def connection_is_mariadb(connection: BaseDatabaseWrapper) -> bool:
-    return connection.vendor == "mysql" and connection.mysql_is_mariadb
-
-
 def settings_to_cmd_args(settings_dict: dict[str, Any]) -> list[str]:
     """
     Copied from django 1.8 MySQL backend DatabaseClient - where the runshell

src/django_mysql/utils.py

@@ -33,7 +33,6 @@
     SizedBinaryField,
     SizedTextField,
 )
-from django_mysql.utils import connection_is_mariadb
 
 
 class EnumModel(Model):
@@ -122,7 +121,7 @@ class DynamicModel(Model):
     @classmethod
     def check(cls, **kwargs):
         # Disable the checks on MySQL so that checks tests don't fail
-        if not (connection_is_mariadb(connection)):
+        if not connection.mysql_is_mariadb:
             return []
         return super().check(**kwargs)
 
@@ -136,7 +135,7 @@ class SpeclessDynamicModel(Model):
     @classmethod
     def check(cls, **kwargs):
         # Disable the checks on MySQL so that checks tests don't fail
-        if not (connection_is_mariadb(connection)):
+        if not connection.mysql_is_mariadb:
             return []
         return super().check(**kwargs)
 

tests/testapp/models.py

@@ -8,21 +8,20 @@
 import pytest
 from django.core import serializers
 from django.core.exceptions import FieldError
-from django.db import connection, models
+from django.db import connection, connections, models
 from django.db.migrations.writer import MigrationWriter
 from django.db.models import CharField, Transform
 from django.test import TestCase
 from django.test.utils import isolate_apps
 
 from django_mysql.models import DynamicField
-from django_mysql.utils import connection_is_mariadb
 from tests.testapp.models import DynamicModel, SpeclessDynamicModel
 
 
 class DynColTestCase(TestCase):
     @classmethod
     def setUpClass(cls):
-        if not (connection_is_mariadb(connection)):
+        if not connection.mysql_is_mariadb:
             raise SkipTest("Dynamic Columns require MariaDB")
         super().setUpClass()
 
@@ -286,14 +285,18 @@ class TestCheck(DynColTestCase):
 
     databases = ["default", "other"]
 
-    @mock.patch("django_mysql.models.fields.dynamic.connection_is_mariadb")
-    def test_db_not_mariadb(self, is_mariadb):
-        is_mariadb.return_value = False
-
+    def test_db_not_mariadb(self):
         class Valid(models.Model):
             field = DynamicField()
 
-        errors = Valid.check()
+        mock_default = mock.patch.object(
+            connections["default"], "mysql_is_mariadb", False
+        )
+        mock_other = mock.patch.object(connections["other"], "mysql_is_mariadb", False)
+
+        with mock_default, mock_other:
+            errors = Valid.check()
+
         assert len(errors) == 1
         assert errors[0].id == "django_mysql.E013"
         assert "MariaDB is required" in errors[0].msg

tests/testapp/test_dynamicfield.py

@@ -37,7 +37,6 @@
     UpdateXML,
     XMLExtractValue,
 )
-from django_mysql.utils import connection_is_mariadb
 from tests.testapp.models import Alphabet, Author, DynamicModel, JSONModel
 from tests.testapp.test_dynamicfield import DynColTestCase
 from tests.testapp.utils import print_all_queries
@@ -604,7 +603,7 @@ def test_json_array_append(self):
 class RegexpFunctionTests(TestCase):
     def setUp(self):
         super().setUp()
-        if not connection_is_mariadb(connection):
+        if not connection.mysql_is_mariadb:
             raise SkipTest("MariaDB is required")
 
     def test_regex_instr(self):

tests/testapp/test_functions.py

@@ -12,7 +12,6 @@
 from django_mysql.exceptions import TimeoutError
 from django_mysql.locks import Lock, TableLock
 from django_mysql.models import Model
-from django_mysql.utils import connection_is_mariadb
 from tests.testapp.models import (
     AgedCustomer,
     Alphabet,
@@ -30,7 +29,7 @@ class LockTests(TestCase):
     def setUpClass(cls):
         super().setUpClass()
 
-        cls.supports_lock_info = connection_is_mariadb(connection)
+        cls.supports_lock_info = connection.mysql_is_mariadb
         if cls.supports_lock_info:
             with connection.cursor() as cursor:
                 cursor.execute(
@@ -237,7 +236,7 @@ def is_locked(self, connection_name, table_name):
             if rows:
                 assert len(rows) == 1
                 return rows[0][2] > 0
-            else:
+            else:  # pragma: no cover
                 # MySQL 8+ closes the table really quickly. If it's closed,
                 # it's not locked.
                 return False