Ticket #14799: t14799.diff

django/test/simple.py

@@ -222 +222 @@
         # and which ones are test mirrors or duplicate entries in DATABASES
         mirrored_aliases = {}
         test_databases = {}
+        db_dependencies = {}
         for alias in connections:
             connection = connections[alias]
             if connection.settings_dict['TEST_MIRROR']:
@@ -239 +240 @@
                         connection.settings_dict['NAME'],
                     ), []).append(alias)
 
+                if 'TEST_DEPENDENCIES' in connection.settings_dict:
+                    db_dependencies[alias] = connection.settings_dict['TEST_DEPENDENCIES']
+                else:
+                    if alias != 'default':
+                        db_dependencies[alias] = connection.settings_dict.get('TEST_DEPENDENCIES', ['default'])
+
+        # Ensure that the order in which the test databases are created
+        # satisfies any dependencies between databases.
+        ordered_test_databases = []
+        resolved_databases = set()
+        test_databases = test_databases.items()
+        while test_databases:
+            changed = False
+            deferred = []
+
+            while test_databases:
+                signature, aliases = test_databases.pop()
+
+                dependencies_satisfied = True
+                for alias in aliases:
+                    if alias in db_dependencies:
+                        if all(a in resolved_databases for a in db_dependencies[alias]):
+                            # all dependencies for this alias are satisfied
+                            db_dependencies.pop(alias)
+                            resolved_databases.add(alias)
+                    else:
+                        resolved_databases.add(alias)
+
+                if dependencies_satisfied:
+                    ordered_test_databases.append((signature, aliases))
+                    changed = True
+                else:
+                    deferred.append((signature, aliases))
+
+            if not changed:
+                raise Exception("Circular dependency in TEST_DEPENDENCIES")
+            test_databases = deferred
+
         # Second pass -- actually create the databases.
         old_names = []
         mirrors = []
-        for (host, port, engine, db_name), aliases in test_databases.items():
+        for (host, port, engine, db_name), aliases in ordered_test_databases:
             # Actually create the database for the first connection
             connection = connections[aliases[0]]
             old_names.append((connection, db_name, True))