refactor: use TypedDict

Signed-off-by: Henry Schreiner <[email protected]>

Author: henryiii

src/scikit_build_core/settings/documentation.py

@@ -4,21 +4,18 @@
 import dataclasses
 import inspect
 import textwrap
+import typing
 from pathlib import Path
-from typing import TYPE_CHECKING, TypeVar, cast
 
 from packaging.specifiers import SpecifierSet
 from packaging.version import Version
 
 from .. import __version__
 from .._compat.typing import get_args, get_origin
 
-if TYPE_CHECKING:
+if typing.TYPE_CHECKING:
     from collections.abc import Generator
 
-T = TypeVar("T")
-U = TypeVar("U")
-
 
 __all__ = ["pull_docs"]
 
@@ -65,12 +62,6 @@ def __str__(self) -> str:
         return f"{docs}\n{self.name} = {self.default}\n"
 
 
-def get_metadata_field(field: dataclasses.Field[U], field_name: str, default: T) -> T:
-    if field_name in field.metadata:
-        return cast("T", field.metadata[field_name])
-    return default
-
-
 def sanitize_default_field(text: str) -> str:
     return text.replace("'", '"').replace("True", "true").replace("False", "false")
 
@@ -94,7 +85,9 @@ def mk_docs(dc: type[object], prefix: str = "") -> Generator[DCDoc, None, None]:
                 yield from mk_docs(field_type, prefix=f"{prefix}{field.name}[].")
                 continue
 
-        if default_before_format := get_metadata_field(field, "display_default", None):
+        if default_before_format := field.metadata.get("skbuild", {}).get(
+            "display_default", None
+        ):
             assert isinstance(default_before_format, str)
             default = default_before_format.format(
                 version=version_display,
@@ -114,5 +107,5 @@ def mk_docs(dc: type[object], prefix: str = "") -> Generator[DCDoc, None, None]:
             name=f"{prefix}{field.name}".replace("_", "-"),
             default=sanitize_default_field(default),
             docs=docs[field.name],
-            deprecated=get_metadata_field(field, "deprecated", False),  # noqa: FBT003
+            deprecated=field.metadata.get("skbuild", {}).get("deprecated", False),
         )

src/scikit_build_core/settings/skbuild_model.py

@@ -1,7 +1,6 @@
 import dataclasses
-from collections.abc import Iterator, Mapping
 from pathlib import Path
-from typing import Any, Dict, List, Literal, Optional, Union
+from typing import Any, Dict, List, Literal, Optional, TypedDict, Union
 
 from packaging.specifiers import SpecifierSet
 from packaging.version import Version
@@ -22,6 +21,7 @@
     "SDistSettings",
     "ScikitBuildSettings",
     "SearchSettings",
+    "SettingsFieldMetadata",
     "WheelSettings",
 ]
 
@@ -30,27 +30,26 @@ def __dir__() -> List[str]:
     return __all__
 
 
-@dataclasses.dataclass
-class SettingsFieldMetadata(Mapping):  # type: ignore[type-arg]
-    """
-    Convenience dataclass to store field metadata for documentation.
-    """
-
-    display_default: Optional[str] = None
-    deprecated: bool = False
+class SettingsFieldMetadataInner(TypedDict):
+    display_default: Optional[str]
+    deprecated: bool
 
-    def __contains__(self, key: Any) -> bool:
-        return any(key == field.name for field in dataclasses.fields(self))
 
-    def __getitem__(self, key: str) -> Any:
-        return getattr(self, key)
+class SettingsFieldMetadata(TypedDict, total=False):
+    skbuild: SettingsFieldMetadataInner
 
-    def __len__(self) -> int:
-        return len(dataclasses.fields(self))
 
-    def __iter__(self) -> "Iterator[str]":
-        for field in dataclasses.fields(self):
-            yield field.name
+def mk_metadata(
+    *, display_default: Optional[str] = None, deprecated: bool = False
+) -> SettingsFieldMetadata:
+    """
+    A helper function to create metadata for a field.
+    """
+    return SettingsFieldMetadata(
+        skbuild=SettingsFieldMetadataInner(
+            display_default=display_default, deprecated=deprecated
+        )
+    )
 
 
 class CMakeSettingsDefine(str):
@@ -78,7 +77,7 @@ def escape_semicolons(item: str) -> str:
 @dataclasses.dataclass
 class CMakeSettings:
     minimum_version: Optional[Version] = dataclasses.field(
-        default=None, metadata=SettingsFieldMetadata(deprecated=True)
+        default=None, metadata=mk_metadata(deprecated=True)
     )
     """
     DEPRECATED in 0.8; use version instead.
@@ -141,7 +140,7 @@ class SearchSettings:
 @dataclasses.dataclass
 class NinjaSettings:
     minimum_version: Optional[Version] = dataclasses.field(
-        default=None, metadata=SettingsFieldMetadata(deprecated=True)
+        default=None, metadata=mk_metadata(deprecated=True)
     )
     """
     DEPRECATED in 0.8; use version instead.
@@ -204,7 +203,7 @@ class SDistSettings:
 class WheelSettings:
     packages: Optional[Union[List[str], Dict[str, str]]] = dataclasses.field(
         default=None,
-        metadata=SettingsFieldMetadata(
+        metadata=mk_metadata(
             display_default='["src/<package>", "python/<package>", "<package>"]'
         ),
     )
@@ -334,7 +333,7 @@ class InstallSettings:
     """
 
     strip: Optional[bool] = dataclasses.field(
-        default=None, metadata=SettingsFieldMetadata(display_default="true")
+        default=None, metadata=mk_metadata(display_default="true")
     )
     """
     Whether to strip the binaries. True for release builds on scikit-build-core
@@ -419,9 +418,7 @@ class ScikitBuildSettings:
 
     minimum_version: Optional[Version] = dataclasses.field(
         default=None,
-        metadata=SettingsFieldMetadata(
-            display_default='"{version}"  # current version'
-        ),
+        metadata=mk_metadata(display_default='"{version}"  # current version'),
     )
     """
     If set, this will provide a method for backward compatibility.