feat: Use a typing proxy to avoid imports/backports

Author: effigies

src/bids_validator/types/_context.py

@@ -13,18 +13,21 @@
     load_schema_into_namespace(schema['meta']['context'], globals(), 'Context')
 """
 
+from __future__ import annotations
+
 import json
-from typing import Any, Union
 
 import attrs
 import bidsschematools as bst
 import bidsschematools.schema
 
+from . import _typings as t
+
 LATEST_SCHEMA_URL = 'https://bids-specification.readthedocs.io/en/latest/schema.json'
 STABLE_SCHEMA_URL = 'https://bids-specification.readthedocs.io/en/stable/schema.json'
 
 
-def get_schema(url: Union[str, None] = None) -> bst.types.Namespace:
+def get_schema(url: str | None = None) -> bst.types.Namespace:
     """Load a BIDS schema from a URL or return the bundled schema if no URL is provided.
 
     This function utilizes the ``universal_pathlib`` package to handle various URL schemes.
@@ -75,7 +78,7 @@ def snake_to_pascal(val: str) -> str:
     return ''.join(sub.capitalize() for sub in val.split('_'))
 
 
-def typespec_to_type(name: str, typespec: dict[str, Any]) -> tuple[type, dict[str, Any]]:
+def typespec_to_type(name: str, typespec: dict[str, t.Any]) -> tuple[type, dict[str, t.Any]]:
     """Convert JSON-schema style specification to type and metadata dictionary."""
     tp = typespec.get('type')
     if not tp:
@@ -86,12 +89,12 @@ def typespec_to_type(name: str, typespec: dict[str, Any]) -> tuple[type, dict[st
         if properties:
             type_ = create_attrs_class(name, properties=properties, metadata=metadata)
         else:
-            type_ = dict[str, Any]
+            type_ = dict[str, t.Any]
     elif tp == 'array':
         if 'items' in typespec:
             subtype, md = typespec_to_type(name, typespec['items'])
         else:
-            subtype = Any
+            subtype = t.Any
         type_ = list[subtype]
     else:
         type_ = {
@@ -111,8 +114,8 @@ def _type_name(tp: type) -> str:
 
 def create_attrs_class(
     class_name: str,
-    properties: dict[str, Any],
-    metadata: dict[str, Any],
+    properties: dict[str, t.Any],
+    metadata: dict[str, t.Any],
 ) -> type:
     """Dynamically create an attrs class with the given properties.
 
@@ -160,7 +163,7 @@ def create_attrs_class(
 
 
 def generate_attrs_classes_from_schema(
-    schema: dict[str, Any],
+    schema: dict[str, t.Any],
     root_class_name: str,
 ) -> type:
     """Generate attrs classes from a JSON schema.
@@ -185,7 +188,7 @@ def generate_attrs_classes_from_schema(
     return type_
 
 
-def populate_namespace(attrs_class: type, namespace: dict[str, Any]) -> None:
+def populate_namespace(attrs_class: type, namespace: dict[str, t.Any]) -> None:
     """Populate a namespace with nested attrs classes.
 
     Parameters
@@ -205,8 +208,8 @@ def populate_namespace(attrs_class: type, namespace: dict[str, Any]) -> None:
 
 
 def load_schema_into_namespace(
-    schema: dict[str, Any],
-    namespace: dict[str, Any],
+    schema: dict[str, t.Any],
+    namespace: dict[str, t.Any],
     root_class_name: str,
 ) -> None:
     """Load a JSON schema into a namespace as attrs classes.

src/bids_validator/types/_typings.py

@@ -0,0 +1,19 @@
+__all__ = (
+    'Self',
+    'TYPE_CHECKING',
+    'Any',
+)
+
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from typing import Any, Self
+else:
+
+    def __getattr__(name: str):
+        if name in __all__:
+            import typing
+
+            return getattr(typing, name)
+
+        msg = f'Module {__name__!r} has no attribute {name!r}'
+        raise AttributeError(msg)

src/bids_validator/types/files.py

@@ -1,14 +1,16 @@
 """Types for working with file trees."""
 
+from __future__ import annotations
+
 import os
 import posixpath
 import stat
 from functools import cached_property
 from pathlib import Path
-from typing import Union
 
 import attrs
-from typing_extensions import Self  # PY310
+
+from . import _typings as t
 
 __all__ = ('FileTree',)
 
@@ -58,7 +60,7 @@ def is_symlink(self) -> bool:
         return stat.S_ISLNK(_stat.st_mode)
 
 
-def as_direntry(obj: os.PathLike) -> Union[os.DirEntry, UserDirEntry]:
+def as_direntry(obj: os.PathLike) -> os.DirEntry | UserDirEntry:
     """Convert PathLike into DirEntry-like object."""
     if isinstance(obj, os.DirEntry):
         return obj
@@ -69,10 +71,10 @@ def as_direntry(obj: os.PathLike) -> Union[os.DirEntry, UserDirEntry]:
 class FileTree:
     """Represent a FileTree with cached metadata."""
 
-    direntry: Union[os.DirEntry, UserDirEntry] = attrs.field(repr=False, converter=as_direntry)
-    parent: Union['FileTree', None] = attrs.field(repr=False, default=None)
+    direntry: os.DirEntry | UserDirEntry = attrs.field(repr=False, converter=as_direntry)
+    parent: FileTree | None = attrs.field(repr=False, default=None)
     is_dir: bool = attrs.field(default=False)
-    children: dict[str, 'FileTree'] = attrs.field(repr=False, factory=dict)
+    children: dict[str, FileTree] = attrs.field(repr=False, factory=dict)
     name: str = attrs.field(init=False)
 
     def __attrs_post_init__(self):
@@ -85,8 +87,8 @@ def __attrs_post_init__(self):
     def read_from_filesystem(
         cls,
         direntry: os.PathLike,
-        parent: Union['FileTree', None] = None,
-    ) -> Self:
+        parent: FileTree | None = None,
+    ) -> t.Self:
         """Read a FileTree from the filesystem.
 
         Uses :func:`os.scandir` to walk the directory tree.