Refactor type hints and clean up code

docs/source/explanations.rst

@@ -69,7 +69,7 @@ changes, but complicates adding libs to the objects directly. Since ufoLib2
 intentionally lacks defcon's parent-child object hierarchy, a guideline can't
 follow a link to the containing parent and access its lib. Magically loading
 and storing the ``public.objectLibs`` lib key on loading and saving a UFO adds
-an uncomfortable amount of magic and edge-casiness. What if a client itself
+an uncomfortable amount of magic and edge-cases. What if a client itself
 adds a ``public.objectLibs`` entry for an object that differs from what is in
 that object's lib? Overwrite, ignore, error out? With the ``.objectLib``
 method, this edge case does not exist.

pyproject.toml

@@ -39,6 +39,7 @@ multi_line_output = 3
 profile = "black"
 float_to_top = true
 known_first_party = "ufoLib2"
+split_on_trailing_comma = false
 
 [tool.mypy]
 python_version = "3.10"

src/ufoLib2/constants.py

@@ -12,7 +12,7 @@
 - https://unifiedfontobject.org/versions/ufo3/glyphs/glif/#publicobjectlibs
 """
 
-DATA_LIB_KEY = "com.github.fonttools.ufoLib2.lib.plist.data"
+DATA_LIB_KEY: str = "com.github.fonttools.ufoLib2.lib.plist.data"
 """
 Lib key used for serializing binary data as JSON-encodable string.
 """

src/ufoLib2/converters.py

@@ -1,53 +1,42 @@
 from __future__ import annotations
 
-import sys
+from collections.abc import Callable
 from functools import partial
-from typing import Any, Callable, Tuple, Type, cast
+from typing import Any, cast, get_origin
 
 from attrs import fields, has, resolve_types
 from cattrs import Converter
 from cattrs.gen import make_dict_structure_fn, make_dict_unstructure_fn, override
 from cattrs.gen._consts import AttributeOverride
 from fontTools.misc.transform import Transform
 
-is_py37 = sys.version_info[:2] == (3, 7)
-
-if is_py37:
-
-    def get_origin(cl: Type[Any]) -> Any:
-        return getattr(cl, "__origin__", None)
-
-else:
-    from typing import get_origin  # type: ignore
-
-
 __all__ = [
     "register_hooks",
     "structure",
     "unstructure",
 ]
 
 
-def is_ufoLib2_class(cls: Type[Any]) -> bool:
+def is_ufoLib2_class(cls: type[Any]) -> bool:
     mod: str = getattr(cls, "__module__", "")
     return mod.split(".")[0] == "ufoLib2"
 
 
-def is_ufoLib2_attrs_class(cls: Type[Any]) -> bool:
-    return is_ufoLib2_class(cls) and (has(cls) or has(get_origin(cls)))
+def is_ufoLib2_attrs_class(cls: type[Any]) -> bool:
+    return is_ufoLib2_class(cls) and (has(cls) or has(get_origin(cls)))  # type: ignore
 
 
-def is_ufoLib2_class_with_custom_unstructure(cls: Type[Any]) -> bool:
+def is_ufoLib2_class_with_custom_unstructure(cls: type[Any]) -> bool:
     return is_ufoLib2_class(cls) and hasattr(cls, "_unstructure")
 
 
-def is_ufoLib2_class_with_custom_structure(cls: Type[Any]) -> bool:
+def is_ufoLib2_class_with_custom_structure(cls: type[Any]) -> bool:
     return is_ufoLib2_class(cls) and hasattr(cls, "_structure")
 
 
 def register_hooks(conv: Converter, allow_bytes: bool = True) -> None:
     def attrs_hook_factory(
-        cls: Type[Any], gen_fn: Callable[..., Callable[..., Any]], structuring: bool
+        cls: type[Any], gen_fn: Callable[..., Callable[..., Any]], structuring: bool
     ) -> Callable[..., Any]:
         base = get_origin(cls)
         if base is None:
@@ -74,7 +63,7 @@ def attrs_hook_factory(
             else:
                 # by default, we omit all Optional attributes (i.e. with None default),
                 # overriding a Converter's global 'omit_if_default' option. Specific
-                # attibutes can still define their own 'omit_if_default' behavior in
+                # attributes can still define their own 'omit_if_default' behavior in
                 # the Attribute.metadata dict.
                 attrib_override = override(
                     omit_if_default=a.metadata.get(
@@ -89,16 +78,16 @@ def attrs_hook_factory(
 
         return gen_fn(cls, conv, **kwargs)
 
-    def custom_unstructure_hook_factory(cls: Type[Any]) -> Callable[[Any], Any]:
+    def custom_unstructure_hook_factory(cls: type[Any]) -> Callable[[Any], Any]:
         return partial(cls._unstructure, converter=conv)
 
-    def custom_structure_hook_factory(cls: Type[Any]) -> Callable[[Any, Any], Any]:
+    def custom_structure_hook_factory(cls: type[Any]) -> Callable[[Any, Any], Any]:
         return partial(cls._structure, converter=conv)
 
-    def unstructure_transform(t: Transform) -> Tuple[float]:
-        return cast(Tuple[float], tuple(t))
+    def unstructure_transform(t: Transform) -> tuple[float]:
+        return cast(tuple[float], tuple(t))
 
-    def structure_transform(t: Tuple[float], _: Any) -> Transform:
+    def structure_transform(t: tuple[float], _: Any) -> Transform:
         return Transform(*t)
 
     conv.register_unstructure_hook_factory(
@@ -109,11 +98,9 @@ def structure_transform(t: Tuple[float], _: Any) -> Transform:
         is_ufoLib2_class_with_custom_unstructure,
         custom_unstructure_hook_factory,
     )
-    conv.register_unstructure_hook(
-        cast(Type[Transform], Transform), unstructure_transform
-    )
+    conv.register_unstructure_hook(Transform, unstructure_transform)
 
-    conv.register_structure_hook(cast(Type[Transform], Transform), structure_transform)
+    conv.register_structure_hook(Transform, structure_transform)
     conv.register_structure_hook_factory(
         is_ufoLib2_attrs_class,
         partial(attrs_hook_factory, gen_fn=make_dict_structure_fn, structuring=True),

src/ufoLib2/objects/anchor.py

@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from attrs import define
 
 from ufoLib2.objects.misc import AttrDictMixin
@@ -22,13 +20,13 @@ class Anchor(AttrDictMixin):
     y: float
     """The y coordinate of the anchor."""
 
-    name: Optional[str] = None
+    name: str | None = None
     """The name of the anchor."""
 
-    color: Optional[str] = None
+    color: str | None = None
     """The color of the anchor."""
 
-    identifier: Optional[str] = None
+    identifier: str | None = None
     """The globally unique identifier of the anchor."""
 
     def move(self, delta: tuple[float, float]) -> None:

src/ufoLib2/objects/component.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import warnings
-from typing import Optional
 
 from attrs import define, field
 from fontTools.misc.transform import Identity, Transform
@@ -33,7 +32,7 @@ class Component:
     transformation: Transform = field(default=Identity, converter=_convert_transform)
     """The affine transformation to apply to the :attr:`.Component.baseGlyph`."""
 
-    identifier: Optional[str] = None
+    identifier: str | None = None
     """The globally unique identifier of the component."""
 
     def move(self, delta: tuple[float, float]) -> None:

src/ufoLib2/objects/contour.py

@@ -1,7 +1,8 @@
 from __future__ import annotations
 
 import warnings
-from typing import Iterable, Iterator, List, MutableSequence, Optional, overload
+from collections.abc import Iterable, Iterator, MutableSequence
+from typing import overload
 
 from attrs import define, field
 from fontTools.pens.basePen import AbstractPen
@@ -42,10 +43,10 @@ class Contour(MutableSequence[Point]):
             contour[0] = anotherPoint
     """
 
-    points: List[Point] = field(factory=list)
+    points: list[Point] = field(factory=list)
     """The list of points in the contour."""
 
-    identifier: Optional[str] = field(default=None, repr=False)
+    identifier: str | None = field(default=None, repr=False)
     """The globally unique identifier of the contour."""
 
     # collections.abc.MutableSequence interface

src/ufoLib2/objects/dataSet.py

@@ -10,7 +10,7 @@
 class DataSet(DataStore):
     """Represents a mapping of POSIX filename strings to arbitrary data bytes.
 
-    Always use forward slahes (/) as directory separators, even on Windows.
+    Always use forward slashes (/) as directory separators, even on Windows.
 
     Behavior:
         DataSet behaves like a dictionary of type ``Dict[str, bytes]``.

src/ufoLib2/objects/features.py

@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import re
-from typing import TYPE_CHECKING, Type
+from typing import TYPE_CHECKING
 
 from attrs import define
 
@@ -41,6 +41,6 @@ def _unstructure(self, converter: Converter) -> str:
         return self.text
 
     @staticmethod
-    def _structure(data: str, cls: Type[Features], converter: Converter) -> Features:
+    def _structure(data: str, cls: type[Features], converter: Converter) -> Features:
         del converter  # unused
         return cls(data)

src/ufoLib2/objects/font.py

@@ -2,21 +2,16 @@
 
 import os
 import shutil
-import sys
 import tempfile
-from typing import (
-    Any,
-    Dict,
+from collections.abc import (
     Iterable,
     Iterator,
     KeysView,
-    List,
     Mapping,
     MutableMapping,
-    Optional,
     Sequence,
-    cast,
 )
+from typing import Any, cast
 
 from attrs import define, field
 from fontTools.ufoLib import UFOFileStructure, UFOReader, UFOWriter
@@ -159,7 +154,7 @@ class Font:
     features: Features = field(factory=Features, converter=_convert_Features)
     """Features: The font Features object."""
 
-    groups: Dict[str, List[str]] = field(factory=dict)
+    groups: dict[str, list[str]] = field(factory=dict[str, list[str]])
     """Dict[str, List[str]]: A mapping of group names to a list of glyph names."""
 
     _kerning: Kerning = field(factory=Kerning, converter=_convert_Kerning)
@@ -179,12 +174,10 @@ class Font:
     """Dict[str, PlistEncodable]: A temporary map of arbitrary plist values."""
 
     # init=False args, set by alternate open/read classmethod constructors
-    _path: Optional[PathLike] = field(default=None, eq=False, init=False)
-    _lazy: Optional[bool] = field(default=None, init=False, eq=False)
-    _reader: Optional[UFOReader] = field(default=None, init=False, eq=False)
-    _fileStructure: Optional[UFOFileStructure] = field(
-        default=None, init=False, eq=False
-    )
+    _path: PathLike | None = field(default=None, eq=False, init=False)
+    _lazy: bool | None = field(default=None, init=False, eq=False)
+    _reader: UFOReader | None = field(default=None, init=False, eq=False)
+    _fileStructure: UFOFileStructure | None = field(default=None, init=False, eq=False)
 
     @classmethod
     def open(cls, path: PathLike, lazy: bool = True, validate: bool = True) -> Font:
@@ -576,10 +569,7 @@ def save(
             if isinstance(path, str) and os.path.exists(path):
                 if overwrite:
                     overwritePath = path
-                    if sys.version_info < (3, 10):
-                        tmp = tempfile.TemporaryDirectory()
-                    else:
-                        tmp = tempfile.TemporaryDirectory(ignore_cleanup_errors=True)
+                    tmp = tempfile.TemporaryDirectory(ignore_cleanup_errors=True)
                     path = os.path.join(tmp.name, os.path.basename(path))
                 else:
                     import errno

src/ufoLib2/objects/glyph.py

@@ -1,7 +1,8 @@
 from __future__ import annotations
 
+from collections.abc import Iterator, Mapping
 from copy import deepcopy
-from typing import Any, Iterator, List, Mapping, Optional, cast
+from typing import Any, Optional, cast
 
 from attrs import define, field
 from fontTools.misc.transform import Transform
@@ -62,15 +63,15 @@ class Glyph:
         :attr:`.Glyph.components` and :attr:`.Glyph.anchors` attributes.
     """
 
-    _name: Optional[str] = None
+    _name: str | None = None
 
     width: float = 0
     """The width of the glyph."""
 
     height: float = 0
     """The height of the glyph."""
 
-    unicodes: List[int] = field(factory=list)
+    unicodes: list[int] = field(factory=list[int])
     """The Unicode code points assigned to the glyph. Note that a glyph can have
     multiple."""
 
@@ -79,17 +80,17 @@ class Glyph:
     _lib: Lib = field(factory=Lib, converter=_convert_Lib)
     """The glyph's mapping of string keys to arbitrary data."""
 
-    note: Optional[str] = None
+    note: str | None = None
     """A free form text note about the glyph."""
 
-    _anchors: List[Anchor] = field(factory=list)
-    components: List[Component] = field(factory=list)
+    _anchors: list[Anchor] = field(factory=list[Anchor])
+    components: list[Component] = field(factory=list[Component])
     """The list of components the glyph contains."""
 
-    contours: List[Contour] = field(factory=list)
+    contours: list[Contour] = field(factory=list[Contour])
     """The list of contours the glyph contains."""
 
-    _guidelines: List[Guideline] = field(factory=list)
+    _guidelines: list[Guideline] = field(factory=list[Guideline])
 
     _tempLib: Lib = field(factory=Lib, converter=_convert_Lib)
     """A temporary map of arbitrary plist values."""

src/ufoLib2/objects/guideline.py

@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from typing import Optional
-
 from attrs import define
 
 from ufoLib2.objects.misc import AttrDictMixin
@@ -17,22 +15,22 @@ class Guideline(AttrDictMixin):
     data composition restrictions.
     """
 
-    x: Optional[float] = None
+    x: float | None = None
     """The origin x coordinate of the guideline."""
 
-    y: Optional[float] = None
+    y: float | None = None
     """The origin y coordinate of the guideline."""
 
-    angle: Optional[float] = None
+    angle: float | None = None
     """The angle of the guideline."""
 
-    name: Optional[str] = None
+    name: str | None = None
     """The name of the guideline, no uniqueness required."""
 
-    color: Optional[str] = None
+    color: str | None = None
     """The color of the guideline."""
 
-    identifier: Optional[str] = None
+    identifier: str | None = None
     """The globally unique identifier of the guideline."""
 
     def __attrs_post_init__(self) -> None: