feat: support PEP 639 (except normalization)

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

pyproject.toml

@@ -126,6 +126,10 @@ version.source = "vcs"
 build.hooks.vcs.version-file = "src/scikit_build_core/_version.py"
 
 
+[tool.uv]
+dev-dependencies = ["scikit-build-core[test]"]
+environments = ["python_version >= '3.10'"]
+
 [tool.uv.pip]
 reinstall-package = ["scikit-build-core"]
 

src/scikit_build_core/build/wheel.py

@@ -235,6 +235,11 @@ def _build_wheel_impl_impl(
         msg = "project.version is not specified, must be statically present or tool.scikit-build metadata.version.provider configured when dynamic"
         raise AssertionError(msg)
 
+    # Verify PEP 639 replaces license-files
+    if metadata.license_files is not None and settings.wheel.license_files:
+        msg = "Both project.license-files and tool.scikit-build.wheel.license-files are set, use only one"
+        raise AssertionError(msg)
+
     # Get the closest (normally) importable name
     normalized_name = metadata.name.replace("-", "_").replace(".", "_")
 
@@ -313,20 +318,30 @@ def _build_wheel_impl_impl(
             install_dir = wheel_dirs[targetlib] / settings.wheel.install_dir
 
         # Include the metadata license.file entry if provided
-        license_file_globs = list(settings.wheel.license_files)
-        if (
-            metadata.license
-            and not isinstance(metadata.license, str)
-            and metadata.license.file
-        ):
-            license_file_globs.append(str(metadata.license.file))
-
-        for y in license_file_globs:
-            for x in Path().glob(y):
-                if x.is_file():
-                    path = wheel_dirs["metadata"] / "licenses" / x
-                    path.parent.mkdir(parents=True, exist_ok=True)
-                    shutil.copy(x, path)
+        if metadata.license_files:
+            license_paths = metadata.license_files
+        else:
+            license_file_globs = settings.wheel.license_files or [
+                "LICEN[CS]E*",
+                "COPYING*",
+                "NOTICE*",
+                "AUTHORS*",
+            ]
+            if (
+                metadata.license
+                and not isinstance(metadata.license, str)
+                and metadata.license.file
+            ):
+                license_file_globs.append(str(metadata.license.file))
+
+            license_paths = [
+                x for y in license_file_globs for x in Path().glob(y) if x.is_file()
+            ]
+
+        for x in license_paths:
+            path = wheel_dirs["metadata"] / "licenses" / x
+            path.parent.mkdir(parents=True, exist_ok=True)
+            shutil.copy(x, path)
 
         if (
             settings.wheel.license_files

src/scikit_build_core/settings/skbuild_model.py

@@ -199,11 +199,11 @@ class WheelSettings:
     root, giving access to "/platlib", "/data", "/headers", and "/scripts".
     """
 
-    license_files: List[str] = dataclasses.field(
-        default_factory=lambda: ["LICEN[CS]E*", "COPYING*", "NOTICE*", "AUTHORS*"]
-    )
+    license_files: Optional[List[str]] = None
     """
     A list of license files to include in the wheel. Supports glob patterns.
+    The default is ``["LICEN[CS]E*", "COPYING*", "NOTICE*", "AUTHORS*"]``.
+    Must not be set if ``project.license-files`` is set.
     """
 
     cmake: bool = True

tests/conftest.py

@@ -334,6 +334,15 @@ def package_simple_purelib_package(
     return package
 
 
+@pytest.fixture
+def package_pep639_pure(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> PackageInfo:
+    package = PackageInfo(
+        "pep639_pure",
+    )
+    process_package(package, tmp_path, monkeypatch)
+    return package
+
+
 def which_mock(name: str) -> str | None:
     if name in {"ninja", "ninja-build", "cmake3", "samu", "gmake", "make"}:
         return None

tests/packages/pep639_pure/pyproject.toml

@@ -0,0 +1,12 @@
+[build-system]
+requires = ["scikit-build-core"]
+build-backend = "scikit_build_core.build"
+
+[project]
+name = "pep639_pure"
+version = "0.1.0"
+license = "MIT"
+license-files = ["LICENSE1.txt", "nested/more/LICENSE2.txt"]
+
+[tool.scikit-build]
+wheel.cmake = false

tests/test_pyproject_pep517.py

@@ -1,5 +1,6 @@
 import gzip
 import hashlib
+import inspect
 import shutil
 import sys
 import tarfile
@@ -27,15 +28,6 @@
 
 [gui_scripts]
 guithing = a.b:c
-"""
-METADATA = """\
-Metadata-Version: 2.1
-Name: CMake.Example
-Version: 0.0.1
-Requires-Python: >=3.7
-Provides-Extra: test
-Requires-Dist: pytest>=6.0; extra == "test"
-
 """
 
 mark_hashes_different = pytest.mark.xfail(
@@ -52,6 +44,19 @@ def compute_uncompressed_hash(inp: Path) -> str:
 
 @pytest.mark.usefixtures("package_simple_pyproject_ext")
 def test_pep517_sdist():
+    expected_metadata = (
+        inspect.cleandoc(
+            """
+            Metadata-Version: 2.1
+            Name: CMake.Example
+            Version: 0.0.1
+            Requires-Python: >=3.7
+            Provides-Extra: test
+            Requires-Dist: pytest>=6.0; extra == "test"
+            """
+        )
+        + "\n\n"
+    )
     dist = Path("dist")
     out = build_sdist("dist")
 
@@ -74,7 +79,7 @@ def test_pep517_sdist():
         pkg_info = f.extractfile("cmake_example-0.0.1/PKG-INFO")
         assert pkg_info
         pkg_info_contents = pkg_info.read().decode()
-        assert pkg_info_contents == METADATA
+        assert pkg_info_contents == expected_metadata
 
 
 @mark_hashes_different
@@ -360,3 +365,82 @@ def test_prepare_metdata_for_build_wheel_by_hand(tmp_path):
         assert metadata.get(k, None) == b
 
     assert len(metadata) == len(answer)
+
+
+@pytest.mark.usefixtures("package_pep639_pure")
+def test_pep639_license_files_metadata():
+    metadata = build.util.project_wheel_metadata(str(Path.cwd()), isolated=False)
+    answer = {
+        "Metadata-Version": ["2.4"],
+        "Name": ["pep639_pure"],
+        "Version": ["0.1.0"],
+        "License-Expression": ["MIT"],
+        "License-File": ["LICENSE1.txt", "nested/more/LICENSE2.txt"],
+    }
+
+    for k, b in answer.items():
+        assert metadata.get_all(k, None) == b
+
+    assert len(metadata) == sum(len(v) for v in answer.values())
+
+
+@pytest.mark.usefixtures("package_pep639_pure")
+def test_pep639_license_files_sdist():
+    expected_metadata = (
+        inspect.cleandoc(
+            """
+                Metadata-Version: 2.4
+                Name: pep639_pure
+                Version: 0.1.0
+                License-Expression: MIT
+                License-File: LICENSE1.txt
+                License-File: nested/more/LICENSE2.txt
+            """
+        )
+        + "\n\n"
+    )
+
+    dist = Path("dist")
+    out = build_sdist("dist")
+
+    (sdist,) = dist.iterdir()
+    assert sdist.name == "pep639_pure-0.1.0.tar.gz"
+    assert sdist == dist / out
+
+    with tarfile.open(sdist) as f:
+        file_names = set(f.getnames())
+        assert file_names == {
+            f"pep639_pure-0.1.0/{x}"
+            for x in (
+                "pyproject.toml",
+                "PKG-INFO",
+                "LICENSE1.txt",
+                "nested/more/LICENSE2.txt",
+            )
+        }
+        pkg_info = f.extractfile("pep639_pure-0.1.0/PKG-INFO")
+        assert pkg_info
+        pkg_info_contents = pkg_info.read().decode()
+        assert pkg_info_contents == expected_metadata
+
+
+@pytest.mark.usefixtures("package_pep639_pure")
+def test_pep639_license_files_wheel():
+    dist = Path("dist")
+    out = build_wheel("dist", {})
+    (wheel,) = dist.glob("pep639_pure-0.1.0-*.whl")
+    assert wheel == dist / out
+
+    with zipfile.ZipFile(wheel) as zf:
+        file_paths = {Path(p) for p in zf.namelist()}
+        with zf.open("pep639_pure-0.1.0.dist-info/METADATA") as f:
+            metadata = f.read().decode("utf-8")
+
+    assert Path("pep639_pure-0.1.0.dist-info/licenses/LICENSE1.txt") in file_paths
+    assert (
+        Path("pep639_pure-0.1.0.dist-info/licenses/nested/more/LICENSE2.txt")
+        in file_paths
+    )
+
+    assert "LICENSE1.txt" in metadata
+    assert "nested/more/LICENSE2.txt" in metadata