Warn deprecated metadata fields in pyproject.toml

Author: abravalheri

Diff for: pytest.ini

@@ -97,3 +97,4 @@ filterwarnings=
 
 	# Suppress known config deprecations still used in tests
     ignore:Deprecated config in `setup.cfg`
+    ignore:Deprecated usage of `tool.setuptools.(provides|obsoletes)`

Diff for: setuptools/config/_apply_pyprojecttoml.py

@@ -24,7 +24,7 @@
 from .._path import StrPath
 from ..errors import RemovedConfigError
 from ..extension import Extension
-from ..warnings import SetuptoolsWarning
+from ..warnings import SetuptoolsDeprecationWarning, SetuptoolsWarning
 
 if TYPE_CHECKING:
     from typing_extensions import TypeAlias
@@ -98,6 +98,12 @@ def _apply_tool_table(dist: Distribution, config: dict, filename: StrPath):
             and has been removed from `pyproject.toml`.
             """
             raise RemovedConfigError("\n".join([cleandoc(msg), suggestion]))
+        elif norm_key in TOOL_TABLE_DEPRECATIONS:
+            SetuptoolsDeprecationWarning.emit(
+                f"Deprecated usage of `tool.setuptools.{field}` in `pyproject.toml`.",
+                see_docs=f"references/keywords.html#keyword-{field}",
+                due_date=(2027, 1, 25),  # introduced in 20 Jan 2025
+            )
 
         norm_key = TOOL_TABLE_RENAMES.get(norm_key, norm_key)
         corresp = TOOL_TABLE_CORRESPONDENCE.get(norm_key, norm_key)
@@ -401,11 +407,13 @@ def _acessor(obj):
 
 TOOL_TABLE_RENAMES = {"script_files": "scripts"}
 TOOL_TABLE_REMOVALS = {
+    "requires": "Please use `[project] dependencies` for Python requirements.",
     "namespace_packages": """
         Please migrate to implicit native namespaces instead.
         See https://packaging.python.org/en/latest/guides/packaging-namespace-packages/.
         """,
 }
+TOOL_TABLE_DEPRECATIONS = ("obsoletes", "provides")
 TOOL_TABLE_CORRESPONDENCE = {
     # Fields with corresponding core metadata need to be marked as static:
     "obsoletes": partial(_set_static_list_metadata, "obsoletes"),

Diff for: setuptools/tests/config/test_apply_pyprojecttoml.py

@@ -24,6 +24,7 @@
 from setuptools.config._apply_pyprojecttoml import _MissingDynamic, _some_attrgetter
 from setuptools.dist import Distribution
 from setuptools.errors import RemovedConfigError
+from setuptools.warnings import SetuptoolsDeprecationWarning
 
 from .downloads import retrieve_file, urls_from_file
 
@@ -347,18 +348,47 @@ def test_pyproject_sets_attribute(self, tmp_path, monkeypatch):
 
 
 class TestDeprecatedFields:
-    def test_namespace_packages(self, tmp_path):
+    @pytest.mark.parametrize(
+        ("field", "value"),
+        [
+            ("provides", "['setuptools']"),
+            ("obsoletes", "['obsoletes']"),
+        ],
+    )
+    def test_still_valid(self, tmp_path, field, value):
+        pyproject = tmp_path / "pyproject.toml"
+        config = f"""
+        [project]
+        name = "myproj"
+        version = "42"
+        [tool.setuptools]
+        {field} = {value}
+        """
+        pyproject.write_text(cleandoc(config), encoding="utf-8")
+        match = f"Deprecated usage of `tool.setuptools.{field}`"
+        with pytest.warns(SetuptoolsDeprecationWarning, match=match):
+            pyprojecttoml.apply_configuration(makedist(tmp_path), pyproject)
+
+    @pytest.mark.parametrize(
+        ("field", "value"),
+        [
+            ("namespace-packages", "['myproj.pkg']"),
+            ("requires", "['setuptools']"),
+        ],
+    )
+    def test_removed(self, tmp_path, field, value):
         pyproject = tmp_path / "pyproject.toml"
-        config = """
+        config = f"""
         [project]
         name = "myproj"
         version = "42"
         [tool.setuptools]
-        namespace-packages = ["myproj.pkg"]
+        {field} = {value}
         """
         pyproject.write_text(cleandoc(config), encoding="utf-8")
-        with pytest.raises(RemovedConfigError, match="namespace-packages"):
+        with pytest.raises((RemovedConfigError, ValueError)) as exc:
             pyprojecttoml.apply_configuration(makedist(tmp_path), pyproject)
+            assert f"tool.setuptools.{field}" in str(exc.value)
 
 
 class TestPresetField:
@@ -498,7 +528,10 @@ def test_mark_static_fields(self, tmp_path, monkeypatch):
         """
         pyproject = Path(tmp_path, "pyproject.toml")
         pyproject.write_text(cleandoc(toml_config), encoding="utf-8")
-        dist = pyprojecttoml.apply_configuration(Distribution({}), pyproject)
+
+        with pytest.warns(SetuptoolsDeprecationWarning, match="Deprecated usage of"):
+            dist = pyprojecttoml.apply_configuration(Distribution({}), pyproject)
+
         assert is_static(dist.install_requires)
         assert is_static(dist.metadata.keywords)
         assert is_static(dist.metadata.classifiers)