ENH: add tests to avoid dependencies getting out of sync again

Author: dnicolodi

tests/test_consistency.py

@@ -0,0 +1,23 @@
+# SPDX-FileCopyrightText: 2021 The meson-python developers
+#
+# SPDX-License-Identifier: MIT
+
+import pathlib
+import sys
+
+
+if sys.version_info >= (3, 11):
+    import tomllib
+else:
+    import tomli as tomllib
+
+
+def test_pyproject_dependencies():
+    pyproject = pathlib.Path(__file__).parent.parent.joinpath('pyproject.toml')
+    with open(pyproject, 'rb') as f:
+        data = tomllib.load(f)
+    build_dependencies = data['build-system']['requires']
+    project_dependencies = data['project']['dependencies']
+    # verify that all build dependencies are project dependencies
+    assert not set(build_dependencies) - set(project_dependencies), \
+        'pyproject.toml is inconsistent: not all "build-system.requires" are in "project.dependencies"'