Support {root:uri} expansion similar to hatchling

Author: LecrisUT

src/scikit_build_core/builder/get_requires.py

@@ -5,6 +5,7 @@
 import importlib.util
 import os
 import sysconfig
+from pathlib import Path
 from typing import TYPE_CHECKING, Literal
 
 from packaging.tags import sys_tags
@@ -66,6 +67,21 @@ def _load_scikit_build_settings(
     return SettingsReader.from_file("pyproject.toml", config_settings).settings
 
 
+class RootPath(type(Path())):  # type: ignore[misc]
+    """Handle ``{root:uri}`` like formatting similar to ``hatchling``."""
+
+    def __format__(self: Path, fmt: str) -> str:
+        command, _, rest = fmt.partition(":")
+        if command == "parent":
+            return self.parent.__format__(rest)
+        if command == "uri" and rest == "":
+            return self.absolute().as_uri()
+        if command == "" and rest == "":
+            return str(self)
+        msg = f"Could not handle format: {fmt}"
+        raise ValueError(msg)
+
+
 @dataclasses.dataclass(frozen=True)
 class GetRequires:
     settings: ScikitBuildSettings = dataclasses.field(
@@ -140,7 +156,8 @@ def dynamic_metadata(self) -> Generator[str, None, None]:
         if self.settings.fail:
             return
 
-        yield from self.settings.build.build_requires
+        for build_require in self.settings.build.build_requires:
+            yield build_require.format(root=RootPath())
 
         for dynamic_metadata in self.settings.metadata.values():
             if "provider" in dynamic_metadata:

tests/packages/dynamic_metadata/build_requires_project.toml

@@ -10,4 +10,4 @@ build-requires = ["foo"]
 
 [[tool.scikit-build.overrides]]
 if.env.LOCAL_FOO = true
-build.build-requires = ["foo @ {root:uri}/foo"]
+build.build-requires = ["foo @ {root:parent:uri}/foo"]

tests/test_dynamic_metadata.py

@@ -360,7 +360,8 @@ def test_build_requires_field(override, monkeypatch) -> None:
     else:
         monkeypatch.delenv("LOCAL_FOO", raising=False)
 
-    with Path("pyproject.toml").open("rb") as ft:
+    pyproject_path = Path("pyproject.toml")
+    with pyproject_path.open("rb") as ft:
         pyproject = tomllib.load(ft)
     state: Literal["sdist", "metadata_wheel"] = (
         "sdist" if override == "sdist" else "metadata_wheel"
@@ -374,9 +375,11 @@ def test_build_requires_field(override, monkeypatch) -> None:
             "foo",
         }
     elif override == "env":
+        # evaluate ../foo as uri
+        foo_path = pyproject_path.parent.parent / "foo"
+        foo_path = foo_path.absolute()
         assert set(GetRequires().dynamic_metadata()) == {
-            # TODO: This should be resolved to actual path
-            "foo @ {root:uri}/foo",
+            f"foo @ {foo_path.as_uri()}",
         }
     elif override == "sdist":
         assert set(GetRequires().dynamic_metadata()) == {