Added tests for many to one relationship fetching

tests/batch_fetch/test_many_to_one_relationships.py

@@ -0,0 +1,47 @@
+import sqlalchemy as sa
+from sqlalchemy_utils import batch_fetch
+from tests import TestCase
+
+
+class TestBatchFetchManyToOneRelationships(TestCase):
+    def create_models(self):
+        class User(self.Base):
+            __tablename__ = 'user'
+            id = sa.Column(sa.Integer, autoincrement=True, primary_key=True)
+            name = sa.Column(sa.Unicode(255))
+
+        class Article(self.Base):
+            __tablename__ = 'article'
+            id = sa.Column(sa.Integer, primary_key=True)
+            name = sa.Column(sa.Unicode(255))
+            author_id = sa.Column(sa.Integer, sa.ForeignKey(User.id))
+
+            author = sa.orm.relationship(
+                User,
+                backref=sa.orm.backref(
+                    'articles'
+                )
+            )
+
+        self.User = User
+        self.Article = Article
+
+    def setup_method(self, method):
+        TestCase.setup_method(self, method)
+        articles = [
+            self.Article(name=u'Article 1', author=self.User(name=u'John')),
+            self.Article(name=u'Article 2', author=self.User(name=u'Matt')),
+        ]
+        self.session.add_all(articles)
+        self.session.commit()
+
+    def test_supports_relationship_attributes(self):
+        articles = self.session.query(self.Article).all()
+        batch_fetch(
+            articles,
+            'author'
+        )
+        query_count = self.connection.query_count
+        assert articles[0].author  # no lazy load should occur
+        assert articles[1].author  # no lazy load should occur
+        assert self.connection.query_count == query_count