Fixed detection of unique=True in embedded documents.

Added some more test cases - thanks to @heyman for the initial
test case.

Closes #172
Refs #171

mongoengine/base.py

@@ -306,6 +306,30 @@ class TopLevelDocumentMetaclass(DocumentMetaclass):
                         for spec in meta['indexes']] + base_indexes
         new_class._meta['indexes'] = user_indexes
 
+        unique_indexes = cls._unique_with_indexes(new_class)
+        new_class._meta['unique_indexes'] = unique_indexes
+
+        for field_name, field in new_class._fields.items():
+            # Check for custom primary key
+            if field.primary_key:
+                current_pk = new_class._meta['id_field']
+                if current_pk and current_pk != field_name:
+                    raise ValueError('Cannot override primary key field')
+
+                if not current_pk:
+                    new_class._meta['id_field'] = field_name
+                    # Make 'Document.id' an alias to the real primary key field
+                    new_class.id = field
+
+        if not new_class._meta['id_field']:
+            new_class._meta['id_field'] = 'id'
+            new_class._fields['id'] = ObjectIdField(db_field='_id')
+            new_class.id = new_class._fields['id']
+
+        return new_class
+
+    @classmethod
+    def _unique_with_indexes(cls, new_class, namespace=""):
         unique_indexes = []
         for field_name, field in new_class._fields.items():
             # Generate a list of indexes needed by uniqueness constraints
@@ -331,28 +355,16 @@ class TopLevelDocumentMetaclass(DocumentMetaclass):
                     unique_fields += unique_with
 
                 # Add the new index to the list
-                index = [(f, pymongo.ASCENDING) for f in unique_fields]
+                index = [("%s%s" % (namespace, f), pymongo.ASCENDING) for f in unique_fields]
                 unique_indexes.append(index)
 
-            # Check for custom primary key
-            if field.primary_key:
-                current_pk = new_class._meta['id_field']
-                if current_pk and current_pk != field_name:
-                    raise ValueError('Cannot override primary key field')
+            # Grab any embedded document field unique indexes
+            if field.__class__.__name__ == "EmbeddedDocumentField":
+                field_namespace = "%s." % field_name
+                unique_indexes += cls._unique_with_indexes(field.document_type,
+                                    field_namespace)
 
-                if not current_pk:
-                    new_class._meta['id_field'] = field_name
-                    # Make 'Document.id' an alias to the real primary key field
-                    new_class.id = field
-
-        new_class._meta['unique_indexes'] = unique_indexes
-
-        if not new_class._meta['id_field']:
-            new_class._meta['id_field'] = 'id'
-            new_class._fields['id'] = ObjectIdField(db_field='_id')
-            new_class.id = new_class._fields['id']
-
-        return new_class
+        return unique_indexes
 
 
 class BaseDocument(object):

tests/document.py

@@ -362,6 +362,10 @@ class DocumentTest(unittest.TestCase):
         post2 = BlogPost(title='test2', slug='test')
         self.assertRaises(OperationError, post2.save)
 
+
+    def test_unique_with(self):
+        """Ensure that unique_with constraints are applied to fields.
+        """
         class Date(EmbeddedDocument):
             year = IntField(db_field='yr')
 
@@ -385,6 +389,63 @@ class DocumentTest(unittest.TestCase):
 
         BlogPost.drop_collection()
 
+    def test_unique_embedded_document(self):
+        """Ensure that uniqueness constraints are applied to fields on embedded documents.
+        """
+        class SubDocument(EmbeddedDocument):
+            year = IntField(db_field='yr')
+            slug = StringField(unique=True)
+
+        class BlogPost(Document):
+            title = StringField()
+            sub = EmbeddedDocumentField(SubDocument)
+
+        BlogPost.drop_collection()
+
+        post1 = BlogPost(title='test1', sub=SubDocument(year=2009, slug="test"))
+        post1.save()
+
+        # sub.slug is different so won't raise exception
+        post2 = BlogPost(title='test2', sub=SubDocument(year=2010, slug='another-slug'))
+        post2.save()
+
+        # Now there will be two docs with the same sub.slug
+        post3 = BlogPost(title='test3', sub=SubDocument(year=2010, slug='test'))
+        self.assertRaises(OperationError, post3.save)
+
+        BlogPost.drop_collection()
+
+    def test_unique_with_embedded_document_and_embedded_unique(self):
+        """Ensure that uniqueness constraints are applied to fields on
+        embedded documents.  And work with unique_with as well.
+        """
+        class SubDocument(EmbeddedDocument):
+            year = IntField(db_field='yr')
+            slug = StringField(unique=True)
+
+        class BlogPost(Document):
+            title = StringField(unique_with='sub.year')
+            sub = EmbeddedDocumentField(SubDocument)
+
+        BlogPost.drop_collection()
+
+        post1 = BlogPost(title='test1', sub=SubDocument(year=2009, slug="test"))
+        post1.save()
+
+        # sub.slug is different so won't raise exception
+        post2 = BlogPost(title='test2', sub=SubDocument(year=2010, slug='another-slug'))
+        post2.save()
+
+        # Now there will be two docs with the same sub.slug
+        post3 = BlogPost(title='test3', sub=SubDocument(year=2010, slug='test'))
+        self.assertRaises(OperationError, post3.save)
+
+        # Now there will be two docs with the same title and year
+        post3 = BlogPost(title='test1', sub=SubDocument(year=2009, slug='test-1'))
+        self.assertRaises(OperationError, post3.save)
+
+        BlogPost.drop_collection()
+
     def test_unique_and_indexes(self):
         """Ensure that 'unique' constraints aren't overridden by
         meta.indexes.