Fixed #36377 -- Added hints support to CreateExtension and subclasses.

5 files changed, 166 insertions, 28 deletions

diff --git a/AUTHORS b/AUTHORS
index f492b36357..7beafefd6f 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -100,6 +100,7 @@ answer newbie questions, and generally made Django that much better:
     Anssi Kääriäinen <akaariai@gmail.com>
     ant9000@netwise.it
     Anthony Briggs <anthony.briggs@gmail.com>
+    anthony sottile
     Anthony Wright <ryow.college@gmail.com>
     Antoine Chéneau <antoine.cheneau@outlook.com>
     Anton Samarchyan <desecho@gmail.com>
diff --git a/django/contrib/postgres/operations.py b/django/contrib/postgres/operations.py
index 84360febf9..c09d7874c1 100644
--- a/django/contrib/postgres/operations.py
+++ b/django/contrib/postgres/operations.py
@@ -13,15 +13,16 @@ class CreateExtension(Operation):
     reversible = True
     category = OperationCategory.ADDITION
 
-    def __init__(self, name):
+    def __init__(self, name, hints=None):
         self.name = name
+        self.hints = hints or {}
 
     def state_forwards(self, app_label, state):
         pass
 
     def database_forwards(self, app_label, schema_editor, from_state, to_state):
         if schema_editor.connection.vendor != "postgresql" or not router.allow_migrate(
-            schema_editor.connection.alias, app_label
+            schema_editor.connection.alias, app_label, **self.hints
         ):
             return
         if not self.extension_exists(schema_editor, self.name):
@@ -42,7 +43,9 @@ class CreateExtension(Operation):
             )
 
     def database_backwards(self, app_label, schema_editor, from_state, to_state):
-        if not router.allow_migrate(schema_editor.connection.alias, app_label):
+        if not router.allow_migrate(
+            schema_editor.connection.alias, app_label, **self.hints
+        ):
             return
         if self.extension_exists(schema_editor, self.name):
             schema_editor.execute(
@@ -69,43 +72,43 @@ class CreateExtension(Operation):
 
 
 class BloomExtension(CreateExtension):
-    def __init__(self):
-        self.name = "bloom"
+    def __init__(self, hints=None):
+        super().__init__("bloom", hints=hints)
 
 
 class BtreeGinExtension(CreateExtension):
-    def __init__(self):
-        self.name = "btree_gin"
+    def __init__(self, hints=None):
+        super().__init__("btree_gin", hints=hints)
 
 
 class BtreeGistExtension(CreateExtension):
-    def __init__(self):
-        self.name = "btree_gist"
+    def __init__(self, hints=None):
+        super().__init__("btree_gist", hints=hints)
 
 
 class CITextExtension(CreateExtension):
-    def __init__(self):
-        self.name = "citext"
+    def __init__(self, hints=None):
+        super().__init__("citext", hints=hints)
 
 
 class CryptoExtension(CreateExtension):
-    def __init__(self):
-        self.name = "pgcrypto"
+    def __init__(self, hints=None):
+        super().__init__("pgcrypto", hints=hints)
 
 
 class HStoreExtension(CreateExtension):
-    def __init__(self):
-        self.name = "hstore"
+    def __init__(self, hints=None):
+        super().__init__("hstore", hints=hints)
 
 
 class TrigramExtension(CreateExtension):
-    def __init__(self):
-        self.name = "pg_trgm"
+    def __init__(self, hints=None):
+        super().__init__("pg_trgm", hints=hints)
 
 
 class UnaccentExtension(CreateExtension):
-    def __init__(self):
-        self.name = "unaccent"
+    def __init__(self, hints=None):
+        super().__init__("unaccent", hints=hints)
 
 
 class NotInTransactionMixin:
diff --git a/docs/ref/contrib/postgres/operations.txt b/docs/ref/contrib/postgres/operations.txt
index 1c4cd562d1..e2b9af4f60 100644
--- a/docs/ref/contrib/postgres/operations.txt
+++ b/docs/ref/contrib/postgres/operations.txt
@@ -41,7 +41,7 @@ them. In that case, connect to your Django database and run the query
 ``CreateExtension``
 ===================
 
-.. class:: CreateExtension(name)
+.. class:: CreateExtension(name, hints=None)
 
     An ``Operation`` subclass which installs a PostgreSQL extension. For common
     extensions, use one of the more specific subclasses below.
@@ -50,63 +50,135 @@ them. In that case, connect to your Django database and run the query
 
         This is a required argument. The name of the extension to be installed.
 
+    .. attribute:: hints
+
+        .. versionadded:: 6.0
+
+        The optional ``hints`` argument will be passed as ``**hints`` to the
+        :meth:`allow_migrate` method of database routers to assist them in
+        :ref:`making routing decisions <topics-db-multi-db-hints>`.
+
 ``BloomExtension``
 ==================
 
-.. class:: BloomExtension()
+.. class:: BloomExtension(hints=None)
 
     Installs the ``bloom`` extension.
 
+    .. attribute:: hints
+
+        .. versionadded:: 6.0
+
+        The optional ``hints`` argument will be passed as ``**hints`` to the
+        :meth:`allow_migrate` method of database routers to assist them in
+        :ref:`making routing decisions <topics-db-multi-db-hints>`.
+
 ``BtreeGinExtension``
 =====================
 
-.. class:: BtreeGinExtension()
+.. class:: BtreeGinExtension(hints=None)
 
     Installs the ``btree_gin`` extension.
 
+    .. attribute:: hints
+
+        .. versionadded:: 6.0
+
+        The optional ``hints`` argument will be passed as ``**hints`` to the
+        :meth:`allow_migrate` method of database routers to assist them in
+        :ref:`making routing decisions <topics-db-multi-db-hints>`.
+
 ``BtreeGistExtension``
 ======================
 
-.. class:: BtreeGistExtension()
+.. class:: BtreeGistExtension(hints=None)
 
     Installs the ``btree_gist`` extension.
 
+    .. attribute:: hints
+
+        .. versionadded:: 6.0
+
+        The optional ``hints`` argument will be passed as ``**hints`` to the
+        :meth:`allow_migrate` method of database routers to assist them in
+        :ref:`making routing decisions <topics-db-multi-db-hints>`.
+
 ``CITextExtension``
 ===================
 
-.. class:: CITextExtension()
+.. class:: CITextExtension(hints=None)
 
     Installs the ``citext`` extension.
 
+    .. attribute:: hints
+
+        .. versionadded:: 6.0
+
+        The optional ``hints`` argument will be passed as ``**hints`` to the
+        :meth:`allow_migrate` method of database routers to assist them in
+        :ref:`making routing decisions <topics-db-multi-db-hints>`.
+
 ``CryptoExtension``
 ===================
 
-.. class:: CryptoExtension()
+.. class:: CryptoExtension(hints=None)
 
     Installs the ``pgcrypto`` extension.
 
+    .. attribute:: hints
+
+        .. versionadded:: 6.0
+
+        The optional ``hints`` argument will be passed as ``**hints`` to the
+        :meth:`allow_migrate` method of database routers to assist them in
+        :ref:`making routing decisions <topics-db-multi-db-hints>`.
+
 ``HStoreExtension``
 ===================
 
-.. class:: HStoreExtension()
+.. class:: HStoreExtension(hints=None)
 
     Installs the ``hstore`` extension and also sets up the connection to
     interpret hstore data for possible use in subsequent migrations.
 
+    .. attribute:: hints
+
+        .. versionadded:: 6.0
+
+        The optional ``hints`` argument will be passed as ``**hints`` to the
+        :meth:`allow_migrate` method of database routers to assist them in
+        :ref:`making routing decisions <topics-db-multi-db-hints>`.
+
 ``TrigramExtension``
 ====================
 
-.. class:: TrigramExtension()
+.. class:: TrigramExtension(hints=None)
 
     Installs the ``pg_trgm`` extension.
 
+    .. attribute:: hints
+
+        .. versionadded:: 6.0
+
+        The optional ``hints`` argument will be passed as ``**hints`` to the
+        :meth:`allow_migrate` method of database routers to assist them in
+        :ref:`making routing decisions <topics-db-multi-db-hints>`.
+
 ``UnaccentExtension``
 =====================
 
-.. class:: UnaccentExtension()
+.. class:: UnaccentExtension(hints=None)
 
     Installs the ``unaccent`` extension.
 
+    .. attribute:: hints
+
+        .. versionadded:: 6.0
+
+        The optional ``hints`` argument will be passed as ``**hints`` to the
+        :meth:`allow_migrate` method of database routers to assist them in
+        :ref:`making routing decisions <topics-db-multi-db-hints>`.
+
 .. _manage-postgresql-collations:
 
 Managing collations using migrations
diff --git a/docs/releases/6.0.txt b/docs/releases/6.0.txt
index c5fa1bac63..9d8120f5c2 100644
--- a/docs/releases/6.0.txt
+++ b/docs/releases/6.0.txt
@@ -135,6 +135,14 @@ Minor features
   now include system checks to verify that ``django.contrib.postgres`` is an
   installed app.
 
+* The :class:`.CreateExtension`, :class:`.BloomExtension`,
+  :class:`.BtreeGinExtension`, :class:`.BtreeGistExtension`,
+  :class:`.CITextExtension`, :class:`.CryptoExtension`,
+  :class:`.HStoreExtension`, :class:`.TrigramExtension`, and
+  :class:`.UnaccentExtension` operations now support the optional ``hints``
+  parameter. This allows providing database hints to database routers to assist
+  them in :ref:`making routing decisions <topics-db-multi-db-hints>`.
+
 :mod:`django.contrib.redirects`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/tests/postgres_tests/test_operations.py b/tests/postgres_tests/test_operations.py
index 322f38148b..551898c80a 100644
--- a/tests/postgres_tests/test_operations.py
+++ b/tests/postgres_tests/test_operations.py
@@ -238,6 +238,11 @@ class NoMigrationRouter:
         return False
 
 
+class MigrateWhenHinted:
+    def allow_migrate(self, db, app_label, **hints):
+        return hints.get("a_hint", False)
+
+
 @unittest.skipUnless(connection.vendor == "postgresql", "PostgreSQL specific tests.")
 class CreateExtensionTests(PostgreSQLTestCase):
     app_label = "test_allow_create_extention"
@@ -289,6 +294,55 @@ class CreateExtensionTests(PostgreSQLTestCase):
         self.assertEqual(len(captured_queries), 2)
         self.assertIn("DROP EXTENSION IF EXISTS", captured_queries[1]["sql"])
 
+    @override_settings(DATABASE_ROUTERS=[MigrateWhenHinted()])
+    def test_allow_migrate_based_on_hints(self):
+        operation_no_hints = CreateExtension("tablefunc")
+        self.assertEqual(operation_no_hints.hints, {})
+
+        operation_hints = CreateExtension("tablefunc", hints={"a_hint": True})
+        self.assertEqual(operation_hints.hints, {"a_hint": True})
+
+        project_state = ProjectState()
+        new_state = project_state.clone()
+
+        with (
+            CaptureQueriesContext(connection) as captured_queries,
+            connection.schema_editor(atomic=False) as editor,
+        ):
+            operation_no_hints.database_forwards(
+                self.app_label, editor, project_state, new_state
+            )
+        self.assertEqual(len(captured_queries), 0)
+
+        with (
+            CaptureQueriesContext(connection) as captured_queries,
+            connection.schema_editor(atomic=False) as editor,
+        ):
+            operation_no_hints.database_backwards(
+                self.app_label, editor, project_state, new_state
+            )
+        self.assertEqual(len(captured_queries), 0)
+
+        with (
+            CaptureQueriesContext(connection) as captured_queries,
+            connection.schema_editor(atomic=False) as editor,
+        ):
+            operation_hints.database_forwards(
+                self.app_label, editor, project_state, new_state
+            )
+        self.assertEqual(len(captured_queries), 4)
+        self.assertIn("CREATE EXTENSION IF NOT EXISTS", captured_queries[1]["sql"])
+
+        with (
+            CaptureQueriesContext(connection) as captured_queries,
+            connection.schema_editor(atomic=False) as editor,
+        ):
+            operation_hints.database_backwards(
+                self.app_label, editor, project_state, new_state
+            )
+        self.assertEqual(len(captured_queries), 2)
+        self.assertIn("DROP EXTENSION IF EXISTS", captured_queries[1]["sql"])
+
     def test_create_existing_extension(self):
         operation = BloomExtension()
         self.assertEqual(operation.migration_name_fragment, "create_extension_bloom")