Enforce 100% test coverage

Author: Cito

src/graphql_relay/mutation/mutation.py

@@ -2,7 +2,6 @@
 from typing import Any, Callable, Dict, Optional
 
 from graphql import (
-    GraphQLError,
     GraphQLArgument,
     GraphQLField,
     GraphQLFieldMap,
@@ -15,7 +14,7 @@
     GraphQLString,
     Thunk,
 )
-from graphql.pyutils import AwaitableOrValue, inspect
+from graphql.pyutils import AwaitableOrValue
 
 # Note: Contrary to the Javascript implementation of MutationFn,
 # the context is passed as part of the GraphQLResolveInfo and any arguments

tests/connection/test_array_connection.py

@@ -400,16 +400,21 @@ def returns_an_edges_cursor_given_an_array_without_index_method():
                 class LettersWithoutIndex:
                     __getitem__ = letters.__getitem__
 
-                letters_without_index = LettersWithoutIndex()
+                letters_without_index = cast(Sequence, LettersWithoutIndex())
 
                 with raises(AttributeError):
-                    cast(Sequence, letters_without_index).index("B")
+                    letters_without_index.index("B")
 
                 letter_b_cursor = cursor_for_object_in_connection(
-                    cast(Sequence, letters_without_index), "B"
+                    letters_without_index, "B"
                 )
                 assert letter_b_cursor == "YXJyYXljb25uZWN0aW9uOjE="
 
+                no_letter_cursor = cursor_for_object_in_connection(
+                    letters_without_index, "="
+                )
+                assert no_letter_cursor is None
+
     def describe_extended_functionality():
         """Test functionality that is not part of graphql-relay-js."""
 

tests/mutation/test_mutation.py

@@ -154,11 +154,36 @@ def can_access_root_value():
         )
 
     def supports_mutations_returning_null():
+        def null_resolve(_info, **_input) -> None:
+            return None
+
+        some_mutation = mutation_with_client_mutation_id(
+            "SomeMutation", {}, {"result": GraphQLField(GraphQLInt)}, null_resolve
+        )
+        schema = wrap_in_schema({"someMutation": some_mutation})
+        source = """
+            mutation {
+              someMutation(input: {clientMutationId: "abc"}) {
+                result
+                clientMutationId
+              }
+            }
+            """
+        assert graphql_sync(schema, source) == (
+            {"someMutation": {"result": None, "clientMutationId": "abc"}},
+            None,
+        )
+
+    @mark.asyncio
+    async def supports_async_mutations_returning_null():
+        async def null_resolve(_info, **_input) -> None:
+            return None
+
         some_mutation = mutation_with_client_mutation_id(
             "SomeMutation",
             {},
             {"result": GraphQLField(GraphQLInt)},
-            lambda _info, **_input: None,
+            null_resolve,
         )
         schema = wrap_in_schema({"someMutation": some_mutation})
         source = """
@@ -169,7 +194,7 @@ def supports_mutations_returning_null():
               }
             }
             """
-        assert graphql_sync(schema, source) == (
+        assert await graphql(schema, source) == (
             {"someMutation": {"result": None, "clientMutationId": "abc"}},
             None,
         )

tests/node/test_global.py

@@ -64,7 +64,7 @@ def get_node(global_id: str, info: GraphQLResolveInfo) -> Any:
                 )
             if type_ == "Post":
                 return next(filter(lambda obj: obj["id"] == id_, post_data), None)
-            return None
+            return None  # pragma: no cover
 
         def get_node_type(
             obj: Any, info: GraphQLResolveInfo, _type: Any
@@ -76,7 +76,7 @@ def get_node_type(
                 return photo_type
             if "text" in obj:
                 return post_type
-            return None
+            return None  # pragma: no cover
 
     else:
 
@@ -89,7 +89,7 @@ def get_node(global_id: str, info: GraphQLResolveInfo) -> Any:
                 return next(filter(lambda obj: obj.photo_id == id_, photo_data), None)
             if type_ == "Post":
                 return next(filter(lambda obj: obj.id == id_, post_data), None)
-            return None
+            return None  # pragma: no cover
 
         def get_node_type(
             obj: Any, info: GraphQLResolveInfo, _type: Any
@@ -101,7 +101,7 @@ def get_node_type(
                 return photo_type
             if isinstance(obj, Post):
                 return post_type
-            return None
+            return None  # pragma: no cover
 
     node_interface, node_field = node_definitions(get_node, get_node_type)[:2]
 

tests/node/test_node.py

@@ -53,7 +53,7 @@ def get_node_type(
         return user_type
     if obj in photo_data:
         return photo_type
-    return None
+    return None  # pragma: no cover
 
 
 node_interface, node_field, nodes_field = node_definitions(get_node, get_node_type)

tests/star_wars_data.py

@@ -44,7 +44,7 @@ def create_ship(ship_name: str, faction_id: str) -> Ship:
     new_ship = Ship(str(len(all_ships) + 1), ship_name)
     all_ships.append(new_ship)
     faction = get_faction(faction_id)
-    if faction:
+    if faction:  # pragma: no cover else
         faction.ships.append(new_ship.id)
     return new_ship
 

tests/star_wars_schema.py

@@ -103,17 +103,15 @@ def get_node(global_id, _info):
     type_, id_ = from_global_id(global_id)
     if type_ == "Faction":
         return get_faction(id_)
-    elif type_ == "Ship":
+    if type_ == "Ship":
         return get_ship(id_)
-    else:
-        return None
+    return None  # pragma: no cover
 
 
 def get_node_type(obj, _info, _type):
     if isinstance(obj, Faction):
         return factionType
-    else:
-        return shipType
+    return shipType
 
 
 node_interface, node_field = node_definitions(get_node, get_node_type)[:2]

tox.ini

@@ -44,4 +44,4 @@ deps =
     pytest-describe>=2,<3
     py36,py37: typing-extensions>=4,<5
 commands =
-    pytest tests {posargs: --cov-report=term-missing --cov=graphql_relay --cov=tests --cov-fail-under=98}
+    pytest tests {posargs: --cov-report=term-missing --cov=graphql_relay --cov=tests --cov-fail-under=100}