scikit-learn
diff --git a/‎sklearn/tests/test_min_dependencies_readme.py
Lines changed: 37 additions & 1 deletion b/‎sklearn/tests/test_min_dependencies_readme.py
Lines changed: 37 additions & 1 deletion
@@ -1,4 +1,4 @@
-"""Tests for the minimum dependencies in the README.rst file."""
+"""Tests for the minimum dependencies in README.rst and pyproject.toml"""
 
 
 import os
@@ -50,3 +50,39 @@ def test_min_dependencies_readme():
                 min_version = parse_version(dependent_packages[package][0])
 
                 assert version == min_version, f"{package} has a mismatched version"
+
+
+def test_min_dependencies_pyproject_toml():
+    """Check versions in pyproject.toml is consistent with _min_dependencies."""
+    # tomllib is available in Python 3.11
+    tomllib = pytest.importorskip("tomllib")
+
+    root_directory = Path(sklearn.__path__[0]).parent
+    pyproject_toml_path = root_directory / "pyproject.toml"
+
+    if not pyproject_toml_path.exists():
+        # Skip the test if the pyproject.toml file is not available.
+        # For instance, when installing scikit-learn from wheels
+        pytest.skip("pyproject.toml is not available.")
+
+    with pyproject_toml_path.open("rb") as f:
+        pyproject_toml = tomllib.load(f)
+
+    build_requirements = pyproject_toml["build-system"]["requires"]
+
+    pyproject_build_min_versions = {}
+    for requirement in build_requirements:
+        if ">=" in requirement:
+            package, version = requirement.split(">=")
+            package = package.lower()
+            pyproject_build_min_versions[package] = version
+
+    # Only scipy and cython are listed in pyproject.toml
+    # NumPy is more complex using oldest-supported-numpy.
+    assert set(["scipy", "cython"]) == set(pyproject_build_min_versions)
+
+    for package, version in pyproject_build_min_versions.items():
+        version = parse_version(version)
+        expected_min_version = parse_version(dependent_packages[package][0])
+
+        assert version == expected_min_version, f"{package} has a mismatched version"