Auto-naming for migrations and some writer fixes

2 files changed, 59 insertions, 15 deletions

diff --git a/tests/migrations/test_autodetector.py b/tests/migrations/test_autodetector.py
index 8e6a1e4160..1fc8f7aefb 100644
--- a/tests/migrations/test_autodetector.py
+++ b/tests/migrations/test_autodetector.py
@@ -2,6 +2,7 @@
 from django.test import TransactionTestCase
 from django.db.migrations.autodetector import MigrationAutodetector
 from django.db.migrations.state import ProjectState, ModelState
+from django.db.migrations.graph import MigrationGraph
 from django.db import models
 
 
@@ -11,6 +12,8 @@ class AutodetectorTests(TransactionTestCase):
     """
 
     author_empty = ModelState("testapp", "Author", [("id", models.AutoField(primary_key=True))])
+    other_pony = ModelState("otherapp", "Pony", [("id", models.AutoField(primary_key=True))])
+    other_stable = ModelState("otherapp", "Stable", [("id", models.AutoField(primary_key=True))])
 
     def make_project_state(self, model_states):
         "Shortcut to make ProjectStates from lists of predefined models"
@@ -19,6 +22,28 @@ class AutodetectorTests(TransactionTestCase):
             project_state.add_model_state(model_state)
         return project_state
 
+    def test_arrange_for_graph(self):
+        "Tests auto-naming of migrations for graph matching."
+        # Make a fake graph
+        graph = MigrationGraph()
+        graph.add_node(("testapp", "0001_initial"), None)
+        graph.add_node(("testapp", "0002_foobar"), None)
+        graph.add_node(("otherapp", "0001_initial"), None)
+        graph.add_dependency(("testapp", "0002_foobar"), ("testapp", "0001_initial"))
+        graph.add_dependency(("testapp", "0002_foobar"), ("otherapp", "0001_initial"))
+        # Use project state to make a new migration change set
+        before = self.make_project_state([])
+        after = self.make_project_state([self.author_empty, self.other_pony, self.other_stable])
+        autodetector = MigrationAutodetector(before, after)
+        changes = autodetector.changes()
+        # Run through arrange_for_graph
+        changes = autodetector.arrange_for_graph(changes, graph)
+        # Make sure there's a new name, deps match, etc.
+        self.assertEqual(changes["testapp"][0].name, "0003_author")
+        self.assertEqual(changes["testapp"][0].dependencies, [("testapp", "0002_foobar")])
+        self.assertEqual(changes["otherapp"][0].name, "0002_pony_stable")
+        self.assertEqual(changes["otherapp"][0].dependencies, [("otherapp", "0001_initial")])
+
     def test_new_model(self):
         "Tests autodetection of new models"
         # Make state
@@ -27,9 +52,9 @@ class AutodetectorTests(TransactionTestCase):
         autodetector = MigrationAutodetector(before, after)
         changes = autodetector.changes()
         # Right number of migrations?
-        self.assertEqual(len(changes), 1)
+        self.assertEqual(len(changes['testapp']), 1)
         # Right number of actions?
-        migration = changes.pop()
+        migration = changes['testapp'][0]
         self.assertEqual(len(migration.operations), 1)
         # Right action?
         action = migration.operations[0]
@@ -44,9 +69,9 @@ class AutodetectorTests(TransactionTestCase):
         autodetector = MigrationAutodetector(before, after)
         changes = autodetector.changes()
         # Right number of migrations?
-        self.assertEqual(len(changes), 1)
+        self.assertEqual(len(changes['testapp']), 1)
         # Right number of actions?
-        migration = changes.pop()
+        migration = changes['testapp'][0]
         self.assertEqual(len(migration.operations), 1)
         # Right action?
         action = migration.operations[0]
diff --git a/tests/migrations/test_writer.py b/tests/migrations/test_writer.py
index 0581d6a4bd..c6ca100c1a 100644
--- a/tests/migrations/test_writer.py
+++ b/tests/migrations/test_writer.py
@@ -1,5 +1,6 @@
 # encoding: utf8
 import datetime
+from django.utils import six
 from django.test import TransactionTestCase
 from django.db.migrations.writer import MigrationWriter
 from django.db import models, migrations
@@ -10,23 +11,33 @@ class WriterTests(TransactionTestCase):
     Tests the migration writer (makes migration files from Migration instances)
     """
 
-    def safe_exec(self, value, string):
+    def safe_exec(self, string, value=None):
         l = {}
         try:
-            exec(string, {}, l)
-        except:
-            self.fail("Could not serialize %r: failed to exec %r" % (value, string.strip()))
+            exec(string, globals(), l)
+        except Exception as e:
+            if value:
+                self.fail("Could not exec %r (from value %r): %s" % (string.strip(), value, e))
+            else:
+                self.fail("Could not exec %r: %s" % (string.strip(), e))
         return l
 
-    def assertSerializedEqual(self, value):
+    def serialize_round_trip(self, value):
         string, imports = MigrationWriter.serialize(value)
-        new_value = self.safe_exec(value, "%s\ntest_value_result = %s" % ("\n".join(imports), string))['test_value_result']
-        self.assertEqual(new_value, value)
+        return self.safe_exec("%s\ntest_value_result = %s" % ("\n".join(imports), string), value)['test_value_result']
+
+    def assertSerializedEqual(self, value):
+        self.assertEqual(self.serialize_round_trip(value), value)
 
     def assertSerializedIs(self, value):
-        string, imports = MigrationWriter.serialize(value)
-        new_value = self.safe_exec(value, "%s\ntest_value_result = %s" % ("\n".join(imports), string))['test_value_result']
-        self.assertIs(new_value, value)
+        self.assertIs(self.serialize_round_trip(value), value)
+
+    def assertSerializedFieldEqual(self, value):
+        new_value = self.serialize_round_trip(value)
+        self.assertEqual(value.__class__, new_value.__class__)
+        self.assertEqual(value.max_length, new_value.max_length)
+        self.assertEqual(value.null, new_value.null)
+        self.assertEqual(value.unique, new_value.unique)
 
     def test_serialize(self):
         """
@@ -48,6 +59,9 @@ class WriterTests(TransactionTestCase):
         self.assertSerializedEqual(datetime.datetime.utcnow)
         self.assertSerializedEqual(datetime.date.today())
         self.assertSerializedEqual(datetime.date.today)
+        # Django fields
+        self.assertSerializedFieldEqual(models.CharField(max_length=255))
+        self.assertSerializedFieldEqual(models.TextField(null=True, blank=True))
 
     def test_simple_migration(self):
         """
@@ -62,4 +76,9 @@ class WriterTests(TransactionTestCase):
         })
         writer = MigrationWriter(migration)
         output = writer.as_string()
-        print output
+        # It should NOT be unicode.
+        self.assertIsInstance(output, six.binary_type, "Migration as_string returned unicode")
+        # We don't test the output formatting - that's too fragile.
+        # Just make sure it runs for now, and that things look alright.
+        result = self.safe_exec(output)
+        self.assertIn("Migration", result)