9 consider typename as metafield with 0 complexity

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "graphql_complexity"
-version = "0.3.1"
+version = "0.3.2"
 description = "A python library that provides complexity calculation helpers for GraphQL"
 authors = ["Checho3388 <ezequiel.grondona@gmail.com>"]
 packages = [

src/graphql_complexity/evaluator/nodes.py

@@ -10,7 +10,7 @@
 )
 
 from graphql_complexity.config import Config
-from graphql_complexity.evaluator.utils import get_node_argument_value
+from graphql_complexity.evaluator.utils import get_node_argument_value, is_meta_type
 
 logger = logging.getLogger(__name__)
 
@@ -107,8 +107,7 @@ def build_node(
 ) -> ComplexityNode:
     """Build a complexity node from a field node."""
     type_ = type_info.get_type()
-    unwrapped_type = get_named_type(type_)
-    if unwrapped_type is not None and is_introspection_type(unwrapped_type):
+    if is_meta_type(type_, node):
         return MetaField(name=node.name.value)
     if isinstance(type_, GraphQLList):
         return build_list_node(node, complexity, variables, config)

src/graphql_complexity/evaluator/utils.py

@@ -1,18 +1,32 @@
 from typing import Any
 
-from graphql import DirectiveNode, FieldNode, VariableNode
+from graphql import (
+    DirectiveNode,
+    FieldNode,
+    VariableNode,
+    get_named_type,
+    is_introspection_type,
+)
 
 
 def get_node_argument_value(node: FieldNode | DirectiveNode, arg_name: str, variables: dict[str, Any]) -> Any:
     """Returns the value of the argument given by parameter."""
-    arg = next(
-        (arg for arg in node.arguments if arg.name.value == arg_name),
-        None
-    )
+    arg = next((arg for arg in node.arguments if arg.name.value == arg_name), None)
     if not arg:
         raise ValueError(f"Value for {arg_name!r} not found in {node.name.value!r} arguments")
 
     if isinstance(arg.value, VariableNode):
         return variables.get(arg.value.name.value)
 
     return arg.value.value
+
+
+def is_meta_type(type_, node) -> bool:
+    """Check if the field is a meta field."""
+    unwrapped_type = get_named_type(type_)
+    return any(
+        (
+            unwrapped_type is not None and is_introspection_type(unwrapped_type),
+            unwrapped_type is not None and node.name.value == "__typename",
+        )
+    )

tests/test_complexity_visitor.py

@@ -24,6 +24,16 @@ def test_one_field_simple_complexity_calculation():
     assert complexity == 1
 
 
+def test_typename_has_zero_complexity():
+    query = """query {
+        __typename
+    }"""
+
+    complexity = _evaluate_complexity(query)
+
+    assert complexity == 0
+
+
 def test_two_fields_simple_complexity_calculation():
     query = """
         query Something {