chore: Use typing.TYPE_CHECKING instead of MYPY (#1503)

Co-authored-by: Erik Wrede <erikwrede@users.noreply.github.com>

graphene/types/inputobjecttype.py

@@ -1,11 +1,12 @@
+from typing import TYPE_CHECKING
+
 from .base import BaseOptions, BaseType
 from .inputfield import InputField
 from .unmountedtype import UnmountedType
 from .utils import yank_fields_from_attrs
 
-# For static type checking with Mypy
-MYPY = False
-if MYPY:
+# For static type checking with type checker
+if TYPE_CHECKING:
     from typing import Dict, Callable  # NOQA
 
 

graphene/types/interface.py

@@ -1,10 +1,11 @@
+from typing import TYPE_CHECKING
+
 from .base import BaseOptions, BaseType
 from .field import Field
 from .utils import yank_fields_from_attrs
 
-# For static type checking with Mypy
-MYPY = False
-if MYPY:
+# For static type checking with type checker
+if TYPE_CHECKING:
     from typing import Dict, Iterable, Type  # NOQA
 
 

graphene/types/mutation.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from ..utils.deprecated import warn_deprecation
 from ..utils.get_unbound_function import get_unbound_function
 from ..utils.props import props
@@ -6,9 +8,8 @@ from .objecttype import ObjectType, ObjectTypeOptions
 from .utils import yank_fields_from_attrs
 from .interface import Interface
 
-# For static type checking with Mypy
-MYPY = False
-if MYPY:
+# For static type checking with type checker
+if TYPE_CHECKING:
     from .argument import Argument  # NOQA
     from typing import Dict, Type, Callable, Iterable  # NOQA
 

graphene/types/objecttype.py

@@ -1,3 +1,5 @@
+from typing import TYPE_CHECKING
+
 from .base import BaseOptions, BaseType, BaseTypeMeta
 from .field import Field
 from .interface import Interface
@@ -7,9 +9,8 @@ try:
     from dataclasses import make_dataclass, field
 except ImportError:
     from ..pyutils.dataclasses import make_dataclass, field  # type: ignore
-# For static type checking with Mypy
-MYPY = False
-if MYPY:
+# For static type checking with type checker
+if TYPE_CHECKING:
     from typing import Dict, Iterable, Type  # NOQA
 
 

graphene/types/union.py

@@ -1,9 +1,10 @@
+from typing import TYPE_CHECKING
+
 from .base import BaseOptions, BaseType
 from .unmountedtype import UnmountedType
 
-# For static type checking with Mypy
-MYPY = False
-if MYPY:
+# For static type checking with type checker
+if TYPE_CHECKING:
     from .objecttype import ObjectType  # NOQA
     from typing import Iterable, Type  # NOQA