feat: Implement | operator on Filtering and Related. (#338)

Co-authored-by: Peter Schutt <peter@topsport.com.au>
Co-authored-by: Jimmy Jia <tesrin@gmail.com>

flask_resty/filtering.py

@@ -211,8 +211,7 @@ def maybe_set_arg_name(self, arg_name):
 
         if self._column_name and self._column_name != arg_name:
             raise TypeError(
-                "cannot use ColumnFilter without explicit column name for "
-                + "multiple arg names"
+                "cannot use ColumnFilter without explicit column name for multiple arg names"
             )
 
         self._column_name = arg_name
@@ -357,3 +356,17 @@ def filter_query(self, query, view):
                 raise e.update({"source": {"parameter": arg_name}})
 
         return query
+
+    def __or__(self, other):
+        """Combine two `Filtering` instances.
+
+        `Filtering` supports view inheritance by implementing the `|` operator.
+        For example, `Filtering(foo=..., bar=...) | Filtering(baz=...)` will
+        create a new `Filtering` instance with filters for each `foo`, `bar`
+        and `baz`. Filters on the right-hand side take precedence where each
+        `Filtering` instance has the same key.
+        """
+        if not isinstance(other, Filtering):
+            return NotImplemented
+
+        return self.__class__(**{**self._arg_filters, **other._arg_filters})

flask_resty/related.py

@@ -160,3 +160,20 @@ def resolve_field(self, value, resolver):
             return [resolve_item(item) for item in value]
 
         return resolve_item(value)
+
+    def __or__(self, other):
+        """Combine two `Related` instances.
+
+        `Related` supports view inheritance by implementing the `|` operator.
+        For example, `Related(foo=..., bar=...) | Related(baz=...)` will create
+        a new `Related` instance with resolvers for each `foo`, `bar` and
+        `baz`. Resolvers on the right-hand side take precedence where each
+        `Related` instance has the same key.
+        """
+        if not isinstance(other, Related):
+            return NotImplemented
+
+        return self.__class__(
+            other._item_class or self._item_class,
+            **{**self._resolvers, **other._resolvers},
+        )

tests/test_filtering.py

@@ -58,7 +58,6 @@ class WidgetViewBase(GenericModelView):
         model = models["widget"]
         schema = schemas["widget"]
 
-    class WidgetListView(WidgetViewBase):
         filtering = Filtering(
             color=operator.eq,
             color_allow_empty=ColumnFilter(
@@ -81,11 +80,14 @@ class WidgetListView(WidgetViewBase):
             ),
         )
 
+    class WidgetListView(WidgetViewBase):
         def get(self):
             return self.list()
 
     class WidgetSizeRequiredListView(WidgetViewBase):
-        filtering = Filtering(size=ColumnFilter(operator.eq, required=True))
+        filtering = WidgetViewBase.filtering | Filtering(
+            size=ColumnFilter(operator.eq, required=True)
+        )
 
         def get(self):
             return self.list()
@@ -206,6 +208,11 @@ def test_column_filter_required_present(client):
     assert_response(response, 200, [{"id": "1", "color": "red", "size": 1}])
 
 
+def test_combine(client):
+    response = client.get("/widgets_size_required?size=1&color=green")
+    assert_response(response, 200, [])
+
+
 def test_column_filter_unvalidated(client):
     response = client.get("/widgets?size_min_unvalidated=-1")
     assert_response(
@@ -333,3 +340,8 @@ def test_error_reuse_column_filter():
 
     with pytest.raises(TypeError, match="without explicit column name"):
         Filtering(foo=implicit_column_filter, bar=implicit_column_filter)
+
+
+def test_error_combine_filtering_type_error():
+    with pytest.raises(TypeError):
+        Filtering() | {}

tests/test_related.py

@@ -17,15 +17,19 @@ class Parent(db.Model):
         id = Column(Integer, primary_key=True)
         name = Column(String)
 
-        children = relationship("Child", backref="parent", cascade="all")
-
     class Child(db.Model):
         __tablename__ = "children"
 
         id = Column(Integer, primary_key=True)
         name = Column(String)
 
         parent_id = Column(ForeignKey(Parent.id))
+        parent = relationship(
+            Parent, foreign_keys=parent_id, backref="children"
+        )
+
+        other_parent_id = Column(ForeignKey(Parent.id))
+        other_parent = relationship(Parent, foreign_keys=other_parent_id)
 
     db.create_all()
 
@@ -40,13 +44,15 @@ class ParentSchema(Schema):
         id = fields.Integer(as_string=True)
         name = fields.String(required=True)
 
-        children = RelatedItem("ChildSchema", many=True, exclude=("parent",))
+        children = RelatedItem(
+            "ChildSchema", many=True, exclude=("parent", "other_parent")
+        )
         child_ids = fields.List(fields.Integer(as_string=True), load_only=True)
 
     class ChildSchema(Schema):
         @classmethod
         def get_query_options(cls, load):
-            return (load.joinedload("parent"),)
+            return (load.joinedload("parent"), load.joinedload("other_parent"))
 
         id = fields.Integer(as_string=True)
         name = fields.String(required=True)
@@ -58,6 +64,10 @@ def get_query_options(cls, load):
             as_string=True, allow_none=True, load_only=True
         )
 
+        other_parent = fields.Nested(
+            ParentSchema, exclude=("children",), allow_none=True
+        )
+
     return {"parent": ParentSchema(), "child": ChildSchema()}
 
 
@@ -110,12 +120,20 @@ class NestedChildView(GenericModelView):
         def put(self, id):
             return self.update(id)
 
+    class ChildWithOtherParentView(ChildView):
+        related = ChildView.related | Related(
+            other_parent=Related(models["parent"])
+        )
+
     api = Api(app)
     api.add_resource("/parents/<int:id>", ParentView)
     api.add_resource("/nested_parents/<int:id>", NestedParentView)
     api.add_resource("/parents_with_create/<int:id>", ParentWithCreateView)
     api.add_resource("/children/<int:id>", ChildView)
     api.add_resource("/nested_children/<int:id>", NestedChildView)
+    api.add_resource(
+        "/children_with_other_parent/<int:id>", ChildWithOtherParentView
+    )
 
 
 @pytest.fixture(autouse=True)
@@ -141,12 +159,16 @@ def test_baseline(client):
 
     child_1_response = client.get("/children/1")
     assert_response(
-        child_1_response, 200, {"id": "1", "name": "Child 1", "parent": None}
+        child_1_response,
+        200,
+        {"id": "1", "name": "Child 1", "parent": None, "other_parent": None},
     )
 
     child_2_response = client.get("/children/2")
     assert_response(
-        child_2_response, 200, {"id": "2", "name": "Child 2", "parent": None}
+        child_2_response,
+        200,
+        {"id": "2", "name": "Child 2", "parent": None, "other_parent": None},
     )
 
 
@@ -163,6 +185,7 @@ def test_single(client):
             "id": "1",
             "name": "Updated Child",
             "parent": {"id": "1", "name": "Parent"},
+            "other_parent": None,
         },
     )
 
@@ -180,6 +203,7 @@ def test_single_nested(client):
             "id": "1",
             "name": "Updated Child",
             "parent": {"id": "1", "name": "Parent"},
+            "other_parent": None,
         },
     )
 
@@ -266,6 +290,7 @@ def test_missing(client):
             "id": "1",
             "name": "Twice Updated Child",
             "parent": {"id": "1", "name": "Parent"},
+            "other_parent": None,
         },
     )
 
@@ -280,7 +305,12 @@ def test_null(client):
     assert_response(
         response,
         200,
-        {"id": "1", "name": "Twice Updated Child", "parent": None},
+        {
+            "id": "1",
+            "name": "Twice Updated Child",
+            "parent": None,
+            "other_parent": None,
+        },
     )
 
 
@@ -294,7 +324,12 @@ def test_null_nested(client):
     assert_response(
         response,
         200,
-        {"id": "1", "name": "Twice Updated Child", "parent": None},
+        {
+            "id": "1",
+            "name": "Twice Updated Child",
+            "parent": None,
+            "other_parent": None,
+        },
     )
 
 
@@ -313,6 +348,29 @@ def test_many_falsy(client):
     )
 
 
+def test_combine(client):
+    response = client.put(
+        "/children_with_other_parent/1",
+        data={
+            "id": "1",
+            "name": "Updated Child",
+            "parent_id": "1",
+            "other_parent": {"id": "2", "name": "Other Parent"},
+        },
+    )
+
+    assert_response(
+        response,
+        200,
+        {
+            "id": "1",
+            "name": "Updated Child",
+            "parent": {"id": "1", "name": "Parent"},
+            "other_parent": {"id": "2", "name": "Other Parent"},
+        },
+    )
+
+
 # -----------------------------------------------------------------------------
 
 
@@ -365,3 +423,8 @@ def test_error_missing_id(client):
             }
         ],
     )
+
+
+def test_error_combine_related_type_error():
+    with pytest.raises(TypeError):
+        Related() | {}