Resolve import cycle by moving TypeInfoVisitor to utilities

Replicates graphql/graphql-js@61a07b1

README.md

@@ -16,7 +16,7 @@ The current stable version 3.0.1 of GraphQL-core is up-to-date
 with GraphQL.js version 14.5.8.
 
 All parts of the API are covered by an extensive test suite
-of currently 2039 unit tests.
+of currently 2040 unit tests.
 
 
 ## Documentation

docs/modules/language.rst

@@ -98,7 +98,6 @@ Visitor
 .. autofunction:: visit
 .. autoclass:: Visitor
 .. autoclass:: ParallelVisitor
-.. autoclass:: TypeInfoVisitor
 
 The module also exports the following special symbols which can be used as
 return values in the :class:`Visitor` methods to signal particular actions:

docs/modules/utilities.rst

@@ -65,6 +65,7 @@ A helper to use within recursive-descent visitors which need to be aware of the
 type system:
 
 .. autoclass:: TypeInfo
+.. autoclass:: TypeInfoVisitor
 
 Coerce a Python value to a GraphQL type, or produce errors:
 

src/graphql/__init__.py

@@ -179,7 +179,6 @@
     # Visit
     visit,
     ParallelVisitor,
-    TypeInfoVisitor,
     Visitor,
     BREAK,
     SKIP,
@@ -362,6 +361,7 @@
     # A helper to use within recursive-descent visitors which need to be aware of the
     # GraphQL type system.
     TypeInfo,
+    TypeInfoVisitor,
     # Coerce a Python value to a GraphQL type, or produce errors.
     coerce_input_value,
     # Concatenates multiple ASTs together.

src/graphql/language/__init__.py

@@ -22,7 +22,6 @@
     visit,
     Visitor,
     ParallelVisitor,
-    TypeInfoVisitor,
     BREAK,
     SKIP,
     REMOVE,
@@ -116,7 +115,6 @@
     "visit",
     "Visitor",
     "ParallelVisitor",
-    "TypeInfoVisitor",
     "BREAK",
     "SKIP",
     "REMOVE",

src/graphql/language/visitor.py

@@ -1,6 +1,5 @@
 from copy import copy
 from typing import (
-    TYPE_CHECKING,
     Any,
     Callable,
     Collection,
@@ -16,13 +15,9 @@
 
 from .ast import Node
 
-if TYPE_CHECKING:  # pragma: no cover
-    from ..utilities import TypeInfo  # noqa: F401
-
 __all__ = [
     "Visitor",
     "ParallelVisitor",
-    "TypeInfoVisitor",
     "visit",
     "BREAK",
     "SKIP",
@@ -378,28 +373,3 @@ def leave(self, node, *args):
                         return result
             elif skipping[i] is node:
                 skipping[i] = None
-
-
-class TypeInfoVisitor(Visitor):
-    """A visitor which maintains a provided TypeInfo."""
-
-    def __init__(self, type_info: "TypeInfo", visitor: Visitor) -> None:
-        self.type_info = type_info
-        self.visitor = visitor
-
-    def enter(self, node, *args):
-        self.type_info.enter(node)
-        fn = self.visitor.get_visit_fn(node.kind)
-        if fn:
-            result = fn(self.visitor, node, *args)
-            if result is not None:
-                self.type_info.leave(node)
-                if isinstance(result, ast.Node):
-                    self.type_info.enter(result)
-            return result
-
-    def leave(self, node, *args):
-        fn = self.visitor.get_visit_fn(node.kind, is_leaving=True)
-        result = fn(self.visitor, node, *args) if fn else None
-        self.type_info.leave(node)
-        return result

src/graphql/utilities/__init__.py

@@ -50,7 +50,7 @@
 
 # A helper to use within recursive-descent visitors which need to be aware of
 # the GraphQL type system
-from .type_info import TypeInfo
+from .type_info import TypeInfo, TypeInfoVisitor
 
 # Coerce a Python value to a GraphQL type, or produce errors.
 from .coerce_input_value import coerce_input_value
@@ -90,6 +90,7 @@
     "DangerousChange",
     "DangerousChangeType",
     "TypeInfo",
+    "TypeInfoVisitor",
     "assert_valid_name",
     "ast_from_value",
     "build_ast_schema",

src/graphql/utilities/find_deprecated_usages.py

@@ -1,9 +1,9 @@
 from typing import List
 
 from ..error import GraphQLError
-from ..language import DocumentNode, TypeInfoVisitor, Visitor, visit
+from ..language import DocumentNode, Visitor, visit
 from ..type import GraphQLSchema, get_named_type
-from .type_info import TypeInfo
+from .type_info import TypeInfo, TypeInfoVisitor
 
 
 __all__ = ["find_deprecated_usages"]

src/graphql/utilities/type_info.py

@@ -14,6 +14,7 @@
     OperationType,
     SelectionSetNode,
     VariableDefinitionNode,
+    Visitor,
 )
 from ..type import (
     GraphQLArgument,
@@ -43,7 +44,7 @@
 )
 from .type_from_ast import type_from_ast
 
-__all__ = ["TypeInfo"]
+__all__ = ["TypeInfo", "TypeInfoVisitor"]
 
 
 GetFieldDefType = Callable[
@@ -282,3 +283,28 @@ def get_field_def(
         parent_type = cast(Union[GraphQLObjectType, GraphQLInterfaceType], parent_type)
         return parent_type.fields.get(name)
     return None
+
+
+class TypeInfoVisitor(Visitor):
+    """A visitor which maintains a provided TypeInfo."""
+
+    def __init__(self, type_info: "TypeInfo", visitor: Visitor) -> None:
+        self.type_info = type_info
+        self.visitor = visitor
+
+    def enter(self, node, *args):
+        self.type_info.enter(node)
+        fn = self.visitor.get_visit_fn(node.kind)
+        if fn:
+            result = fn(self.visitor, node, *args)
+            if result is not None:
+                self.type_info.leave(node)
+                if isinstance(result, Node):
+                    self.type_info.enter(result)
+            return result
+
+    def leave(self, node, *args):
+        fn = self.visitor.get_visit_fn(node.kind, is_leaving=True)
+        result = fn(self.visitor, node, *args) if fn else None
+        self.type_info.leave(node)
+        return result

src/graphql/validation/validate.py

@@ -1,10 +1,10 @@
 from typing import Collection, List
 
 from ..error import GraphQLError
-from ..language import DocumentNode, ParallelVisitor, TypeInfoVisitor, visit
+from ..language import DocumentNode, ParallelVisitor, visit
 from ..type import GraphQLSchema, assert_valid_schema
 from ..pyutils import inspect
-from ..utilities import TypeInfo
+from ..utilities import TypeInfo, TypeInfoVisitor
 from .rules import RuleType
 from .specified_rules import specified_rules, specified_sdl_rules
 from .validation_context import SDLValidationContext, ValidationContext

src/graphql/validation/validation_context.py

@@ -7,13 +7,12 @@
     FragmentSpreadNode,
     OperationDefinitionNode,
     SelectionSetNode,
-    TypeInfoVisitor,
     VariableNode,
     Visitor,
     visit,
 )
 from ..type import GraphQLSchema, GraphQLInputType
-from ..utilities import TypeInfo
+from ..utilities import TypeInfo, TypeInfoVisitor
 
 __all__ = [
     "ASTValidationContext",