Allow introspection

README.md

@@ -1,8 +1,9 @@
 # graphql-complexity
 Python library to compute the complexity of a GraphQL operation
 
-![Unit Tests](https://github.com/Checho3388/graphql-complexity/actions/workflows/python-package.yml/badge.svg)
+![Build](https://github.com/Checho3388/graphql-complexity/actions/workflows/python-buildlu.yml/badge.svg)
 [![PyPI](https://img.shields.io/pypi/v/graphql-complexity?label=pypi%20package)](https://pypi.org/project/graphql-complexity/)
+[![codecov](https://codecov.io/gh/Checho3388/graphql-complexity/graph/badge.svg?token=4LH7AVN119)](https://codecov.io/gh/Checho3388/graphql-complexity)
 
 ## Installation (Quick Start)
 The library can be installed using pip:
@@ -18,6 +19,18 @@ pip install graphql-complexity[strawberry-graphql]
 Create a file named `complexity.py` with the following content:
 ```python
 from graphql_complexity import (get_complexity, SimpleEstimator)
+from graphql import build_schema
+
+
+schema = build_schema("""
+    type User {
+        id: ID!
+        name: String!
+    }
+    type Query {
+        user: User
+    }
+""")
 
 query = """
     query SomeQuery {
@@ -30,6 +43,7 @@ query = """
 
 complexity = get_complexity(
     query=query, 
+    schema=schema,
     estimator=SimpleEstimator(complexity=1, multiplier=10)
 )
 if complexity > 10:
@@ -163,6 +177,7 @@ extension that can be added to the schema.
 
 ```python
 import strawberry
+from graphql_complexity.estimators import SimpleEstimator
 from graphql_complexity.extensions.strawberry_graphql import build_complexity_extension
 
 
@@ -172,7 +187,7 @@ class Query:
     def hello_world(self) -> str:
         return "Hello world!"
 
-extension = build_complexity_extension()
+extension = build_complexity_extension(estimator=SimpleEstimator())
 schema = strawberry.Schema(query=Query, extensions=[extension])
 
 schema.execute_sync("query { helloWorld }")

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "graphql_complexity"
-version = "0.1.0"
+version = "0.2.0"
 description = "A python library that provides complexity calculation helpers for GraphQL"
 authors = ["Checho3388 <[email protected]>"]
 packages = [

src/graphql_complexity/estimators/directive.py

@@ -1,3 +1,5 @@
+from typing import Any
+
 from graphql import Visitor, parse, visit
 
 from graphql_complexity.estimators.base import ComplexityEstimator
@@ -63,7 +65,7 @@ def __init__(
 
     @staticmethod
     def collect_from_schema(schema: str, directive_name: str) -> dict[str, int]:
-        collector = {}
+        collector: dict[str, Any] = {}
         ast = parse(schema)
         visitor = DirectivesVisitor(collector=collector, directive_name=directive_name)
         visit(ast, visitor)

src/graphql_complexity/evaluator/__init__.py

@@ -1,5 +1,9 @@
-from .complexity import get_complexity
+from .complexity import (
+    get_ast_complexity,
+    get_complexity,
+)
 
 __all__ = [
     'get_complexity',
+    'get_ast_complexity'
 ]

src/graphql_complexity/evaluator/complexity.py

@@ -1,18 +1,20 @@
-from graphql import parse, visit
+from graphql import parse, visit, TypeInfo, TypeInfoVisitor, GraphQLSchema
 
-from ..estimators import ComplexityEstimator
 from .visitor import ComplexityVisitor
+from ..estimators import ComplexityEstimator
 
 
-def get_complexity(query: str, estimator: ComplexityEstimator) -> int:
+def get_complexity(query: str, schema: GraphQLSchema, estimator: ComplexityEstimator) -> int:
     """Calculate the complexity of a query using the provided estimator."""
     ast = parse(query)
-    return get_ast_complexity(ast, estimator=estimator)
+    return get_ast_complexity(ast, schema=schema, estimator=estimator)
 
 
-def get_ast_complexity(ast, estimator: ComplexityEstimator) -> int:
+def get_ast_complexity(ast, schema: GraphQLSchema, estimator: ComplexityEstimator) -> int:
     """Calculate the complexity of a query using the provided estimator."""
-    visitor = ComplexityVisitor(estimator=estimator)
-    visit(ast, visitor)
+    type_info = TypeInfo(schema)
+
+    visitor = ComplexityVisitor(estimator=estimator, type_info=type_info)
+    visit(ast, TypeInfoVisitor(type_info, visitor))
 
     return visitor.evaluate()

src/graphql_complexity/evaluator/visitor.py

@@ -10,7 +10,7 @@
     GraphQLSkipDirective,
     OperationDefinitionNode,
     VariableNode,
-    Visitor
+    Visitor, is_introspection_type, get_named_type, TypeInfo
 )
 
 from graphql_complexity.estimators.base import ComplexityEstimator
@@ -61,25 +61,14 @@
 
     The complexity of the operations is calculated by summing the complexity of
     the fields in the operation.
-
-    Examples:
-        >>> from graphql import parse, visit
-        >>> from graphql_complexity.estimators import SimpleEstimator
-        >>> from graphql_complexity.visitor import ComplexityVisitor
-        >>> query = "query { user { name  email } }"
-        >>> ast = parse(query)
-        >>> visitor = ComplexityVisitor(estimator=SimpleEstimator())
-        >>> exc = visit(ast, visitor)
-        >>> visitor.evaluate()
-        3
-
     """
 
-    def __init__(self, estimator: ComplexityEstimator, variables=None):
+    def __init__(self, estimator: ComplexityEstimator, type_info: TypeInfo, variables: dict[str, Any] | None = None):
         if not isinstance(estimator, ComplexityEstimator):
             raise ValueError("Estimator must be of type 'ComplexityEstimator'")
         self.estimator: ComplexityEstimator = estimator
         self.variables = variables or {}
+        self.type_info = type_info
         self._operations: dict[str, list[ComplexityEvaluationNode]] = {}
         self._fragments: dict[str, list[ComplexityEvaluationNode]] = {}
         self._current_complexity_stack: list[ComplexityEvaluationNode] = []
@@ -130,7 +119,13 @@
 
     def enter_field(self, node, key, parent, path, ancestors):
         """Add the complexity of the current field to the current complexity list."""
+        type_ = get_named_type(self.type_info.get_type())
+        if type_ is not None and is_introspection_type(type_):
+            # Skip introspection fields
+            return SKIP
+
         if self._ignore_until_leave is not None:
+            # Skip fields until the parent field is left
             return SKIP
 
         complexity = self.estimator.get_field_complexity(
@@ -149,6 +144,7 @@
             self._ignore_until_leave is not None
             and node.name.value == self._ignore_until_leave.name
         ):
+            # If we are leaving the ignored node, reset the flag
             self._ignore_until_leave = None
 
     def enter_fragment_definition(self, *args, **kwargs):
@@ -168,7 +164,7 @@
         self._current_complexity_stack = []
 
 
-def should_include_field(node: DirectiveNode, variables: dict[str, Any] = None) -> bool:
+def should_include_field(node: DirectiveNode, variables: dict[str, Any]) -> bool:
     """Check if a field should be ignored based on the 'skip' and 'include' directives."""
     if node.name.value == GraphQLIncludeDirective.name:
         return get_directive_if_value(node, variables)
@@ -180,9 +176,12 @@
 
 
 def get_directive_if_value(directive: DirectiveNode, variables: dict[str, Any]) -> bool:
-    """Returns the value of the `if` argument from the Directive"""
+    """Returns the value of the `if` argument from the Directive. Used to get the boolean
+    value for skip/include directives."""
     if_arg = next(arg for arg in directive.arguments if arg.name.value == "if")
     if isinstance(if_arg.value, VariableNode):
-        return variables.get(if_arg.value.name.value)
+        return bool(variables.get(if_arg.value.name.value))
     elif isinstance(if_arg.value, BooleanValueNode):
-        return if_arg.value.value
+        return bool(if_arg.value.value)
+
+    raise ValueError("Value for `if` argument not found")

src/graphql_complexity/extensions/strawberry_graphql.py

@@ -3,25 +3,23 @@
 from graphql import GraphQLError
 from strawberry.extensions import SchemaExtension
 
-from graphql_complexity.estimators import ComplexityEstimator, SimpleEstimator
-from graphql_complexity.evaluator.complexity import get_ast_complexity
+from graphql_complexity.estimators import ComplexityEstimator
+from graphql_complexity.evaluator import get_ast_complexity
 
 
 def build_complexity_extension(
-    estimator: ComplexityEstimator | None = None,
+    estimator: ComplexityEstimator,
     max_complexity: int | None = None,
 ) -> Type[SchemaExtension]:
-    estimator = estimator or SimpleEstimator(1, 1)
-
     class ComplexityExtension(SchemaExtension):
-        visitor = None
-        estimated_complexity: int = None
+        estimated_complexity: int | None = None
 
         def on_validate(
             self,
         ):
             self.estimated_complexity = get_ast_complexity(
                 ast=self.execution_context.graphql_document,
+                schema=self.execution_context.schema._schema,
                 estimator=estimator
             )