Isolated select_for_update tests a bit more.

This change prevents including the multiple_database test models without
duplicating the router code (we probably should do this at one point).

Refs #21148

tests/multiple_database/routers.py

@@ -0,0 +1,61 @@
+from __future__ import unicode_literals
+
+from django.db import DEFAULT_DB_ALIAS
+
+
+class TestRouter(object):
+    # A test router. The behavior is vaguely master/slave, but the
+    # databases aren't assumed to propagate changes.
+    def db_for_read(self, model, instance=None, **hints):
+        if instance:
+            return instance._state.db or 'other'
+        return 'other'
+
+    def db_for_write(self, model, **hints):
+        return DEFAULT_DB_ALIAS
+
+    def allow_relation(self, obj1, obj2, **hints):
+        return obj1._state.db in ('default', 'other') and obj2._state.db in ('default', 'other')
+
+    def allow_migrate(self, db, model):
+        return True
+
+
+class AuthRouter(object):
+    """A router to control all database operations on models in
+    the contrib.auth application"""
+
+    def db_for_read(self, model, **hints):
+        "Point all read operations on auth models to 'default'"
+        if model._meta.app_label == 'auth':
+            # We use default here to ensure we can tell the difference
+            # between a read request and a write request for Auth objects
+            return 'default'
+        return None
+
+    def db_for_write(self, model, **hints):
+        "Point all operations on auth models to 'other'"
+        if model._meta.app_label == 'auth':
+            return 'other'
+        return None
+
+    def allow_relation(self, obj1, obj2, **hints):
+        "Allow any relation if a model in Auth is involved"
+        if obj1._meta.app_label == 'auth' or obj2._meta.app_label == 'auth':
+            return True
+        return None
+
+    def allow_migrate(self, db, model):
+        "Make sure the auth app only appears on the 'other' db"
+        if db == 'other':
+            return model._meta.app_label == 'auth'
+        elif model._meta.app_label == 'auth':
+            return False
+        return None
+
+
+class WriteRouter(object):
+    # A router that only expresses an opinion on writes
+    def db_for_write(self, model, **hints):
+        return 'writer'
+

tests/multiple_database/tests.py

@@ -15,6 +15,7 @@ from django.test.utils import override_settings
 from django.utils.six import StringIO
 
 from .models import Book, Person, Pet, Review, UserProfile
+from .routers import TestRouter, AuthRouter, WriteRouter
 
 
 class QueryTestCase(TestCase):
@@ -919,61 +920,6 @@ class QueryTestCase(TestCase):
                                   extra_arg=True)
 
 
-class TestRouter(object):
-    # A test router. The behavior is vaguely master/slave, but the
-    # databases aren't assumed to propagate changes.
-    def db_for_read(self, model, instance=None, **hints):
-        if instance:
-            return instance._state.db or 'other'
-        return 'other'
-
-    def db_for_write(self, model, **hints):
-        return DEFAULT_DB_ALIAS
-
-    def allow_relation(self, obj1, obj2, **hints):
-        return obj1._state.db in ('default', 'other') and obj2._state.db in ('default', 'other')
-
-    def allow_migrate(self, db, model):
-        return True
-
-class AuthRouter(object):
-    """A router to control all database operations on models in
-    the contrib.auth application"""
-
-    def db_for_read(self, model, **hints):
-        "Point all read operations on auth models to 'default'"
-        if model._meta.app_label == 'auth':
-            # We use default here to ensure we can tell the difference
-            # between a read request and a write request for Auth objects
-            return 'default'
-        return None
-
-    def db_for_write(self, model, **hints):
-        "Point all operations on auth models to 'other'"
-        if model._meta.app_label == 'auth':
-            return 'other'
-        return None
-
-    def allow_relation(self, obj1, obj2, **hints):
-        "Allow any relation if a model in Auth is involved"
-        if obj1._meta.app_label == 'auth' or obj2._meta.app_label == 'auth':
-            return True
-        return None
-
-    def allow_migrate(self, db, model):
-        "Make sure the auth app only appears on the 'other' db"
-        if db == 'other':
-            return model._meta.app_label == 'auth'
-        elif model._meta.app_label == 'auth':
-            return False
-        return None
-
-class WriteRouter(object):
-    # A router that only expresses an opinion on writes
-    def db_for_write(self, model, **hints):
-        return 'writer'
-
-
 class ConnectionRouterTestCase(TestCase):
     @override_settings(DATABASE_ROUTERS=[
         'multiple_database.tests.TestRouter',

tests/select_for_update/tests.py

@@ -10,7 +10,7 @@ from django.db.utils import ConnectionHandler, DEFAULT_DB_ALIAS, DatabaseError
 from django.test import (TransactionTestCase, skipIfDBFeature,
     skipUnlessDBFeature)
 
-from multiple_database.tests import TestRouter
+from multiple_database.routers import TestRouter
 
 from .models import Person