Autodetector tests

django/db/migrations/autodetector.py

@@ -2,7 +2,7 @@ from django.db.migrations import operations
 from django.db.migrations.migration import Migration
 
 
-class AutoDetector(object):
+class MigrationAutodetector(object):
     """
     Takes a pair of ProjectStates, and compares them to see what the
     first would need doing to make it match the second (the second
@@ -27,9 +27,9 @@ class AutoDetector(object):
         # We'll store migrations as lists by app names for now
         self.migrations = {}
         # Stage one: Adding models.
-        added_models = set(self.to_state.keys()) - set(self.from_state.keys())
+        added_models = set(self.to_state.models.keys()) - set(self.from_state.models.keys())
         for app_label, model_name in added_models:
-            model_state = self.to_state[app_label, model_name]
+            model_state = self.to_state.models[app_label, model_name]
             self.add_to_migration(
                 app_label,
                 operations.CreateModel(
@@ -40,9 +40,9 @@ class AutoDetector(object):
                 )
             )
         # Removing models
-        removed_models = set(self.from_state.keys()) - set(self.to_state.keys())
+        removed_models = set(self.from_state.models.keys()) - set(self.to_state.models.keys())
         for app_label, model_name in removed_models:
-            model_state = self.from_state[app_label, model_name]
+            model_state = self.from_state.models[app_label, model_name]
             self.add_to_migration(
                 app_label,
                 operations.DeleteModel(
@@ -59,11 +59,11 @@ class AutoDetector(object):
             for migration in migrations:
                 subclass = type("Migration", (Migration,), migration)
                 instance = subclass(migration['name'], app_label)
-                result.append(instance)
+                result.add(instance)
         return result
 
     def add_to_migration(self, app_label, operation):
         migrations = self.migrations.setdefault(app_label, [])
         if not migrations:
-            migrations.append({"name": "temp-%i" % len(migrations) + 1, "operations": [], "dependencies": []})
+            migrations.append({"name": "auto_%i" % (len(migrations) + 1), "operations": [], "dependencies": []})
-        migrations[-1].operations.append(operation)
+        migrations[-1]['operations'].append(operation)

django/db/migrations/migration.py

@@ -47,6 +47,9 @@ class Migration(object):
     def __repr__(self):
         return "<Migration %s.%s>" % (self.app_label, self.name)
 
+    def __hash__(self):
+        return hash("%s.%s" % (self.app_label, self.name))
+
     def mutate_state(self, project_state):
         """
         Takes a ProjectState and returns a new one with the migration's

tests/migrations/test_autodetector.py

@@ -0,0 +1,54 @@
+# encoding: utf8
+from django.test import TransactionTestCase
+from django.db.migrations.autodetector import MigrationAutodetector
+from django.db.migrations.state import ProjectState, ModelState
+from django.db import models
+
+
+class AutodetectorTests(TransactionTestCase):
+    """
+    Tests the migration autodetector.
+    """
+
+    author_empty = ModelState("testapp", "Author", [("id", models.AutoField(primary_key=True))])
+
+    def make_project_state(self, model_states):
+        "Shortcut to make ProjectStates from lists of predefined models"
+        project_state = ProjectState()
+        for model_state in model_states:
+            project_state.add_model_state(model_state)
+        return project_state
+
+    def test_new_model(self):
+        "Tests autodetection of new models"
+        # Make state
+        before = self.make_project_state([])
+        after = self.make_project_state([self.author_empty])
+        autodetector = MigrationAutodetector(before, after)
+        changes = autodetector.changes()
+        # Right number of migrations?
+        self.assertEqual(len(changes), 1)
+        # Right number of actions?
+        migration = changes.pop()
+        self.assertEqual(len(migration.operations), 1)
+        # Right action?
+        action = migration.operations[0]
+        self.assertEqual(action.__class__.__name__, "CreateModel")
+        self.assertEqual(action.name, "Author")
+
+    def test_old_model(self):
+        "Tests deletion of old models"
+        # Make state
+        before = self.make_project_state([self.author_empty])
+        after = self.make_project_state([])
+        autodetector = MigrationAutodetector(before, after)
+        changes = autodetector.changes()
+        # Right number of migrations?
+        self.assertEqual(len(changes), 1)
+        # Right number of actions?
+        migration = changes.pop()
+        self.assertEqual(len(migration.operations), 1)
+        # Right action?
+        action = migration.operations[0]
+        self.assertEqual(action.__class__.__name__, "DeleteModel")
+        self.assertEqual(action.name, "Author")