Add search vector agg test case

tests/aggregate/test_search_vectors.py

@@ -0,0 +1,56 @@
+import sqlalchemy as sa
+from sqlalchemy_utils import aggregated, TSVectorType
+from tests import TestCase
+
+
+def tsvector_reduce_concat(vectors):
+    return sa.sql.expression.cast(
+        sa.func.coalesce(
+            sa.func.array_to_string(sa.func.array_agg(vectors), ' ')
+        ),
+        TSVectorType
+    )
+
+
+class TestSearchVectorAggregates(TestCase):
+    dns = 'postgres://postgres@localhost/sqlalchemy_utils_test'
+
+    def create_models(self):
+        class Catalog(self.Base):
+            __tablename__ = 'catalog'
+            id = sa.Column(sa.Integer, primary_key=True)
+            name = sa.Column(sa.Unicode(255))
+
+            @aggregated('products', sa.Column(TSVectorType))
+            def product_search_vector(self):
+                return tsvector_reduce_concat(
+                    sa.func.to_tsvector(Product.name)
+                )
+
+            products = sa.orm.relationship('Product', backref='catalog')
+
+        class Product(self.Base):
+            __tablename__ = 'product'
+            id = sa.Column(sa.Integer, primary_key=True)
+            name = sa.Column(sa.Unicode(255))
+            price = sa.Column(sa.Numeric)
+
+            catalog_id = sa.Column(sa.Integer, sa.ForeignKey('catalog.id'))
+
+        self.Catalog = Catalog
+        self.Product = Product
+
+    def test_assigns_aggregates_on_insert(self):
+        catalog = self.Catalog(
+            name=u'Some catalog'
+        )
+        self.session.add(catalog)
+        self.session.commit()
+        product = self.Product(
+            name=u'Product XYZ',
+            catalog=catalog
+        )
+        self.session.add(product)
+        self.session.commit()
+        self.session.refresh(catalog)
+        assert catalog.product_search_vector == "'product':1 'xyz':2"