Add a new TestCase that asserts that examples exit successfully.

tests/test_examples.py

@@ -0,0 +1,75 @@
+"""
+build123d Example tests
+
+name: test_examples.py
+by:   fischman
+date: February 21 2025
+
+desc: Unit tests for the build123d examples, ensuring they don't raise.
+"""
+
+from pathlib import Path
+
+import os
+import subprocess
+import sys
+import tempfile
+import unittest
+
+
+_examples_dir = Path(os.path.abspath(os.path.dirname(__file__))).parent / "examples"
+
+_MOCK_OCP_VSCODE_CONTENTS = """
+import sys
+from unittest.mock import Mock
+mock_module = Mock()
+mock_module.show = Mock()
+mock_module.show_object = Mock()
+mock_module.show_all = Mock()
+sys.modules["ocp_vscode"] = mock_module
+"""
+
+
+def generate_example_test(path: Path):
+    """Generate and return a function to test the example at `path`."""
+    name = path.name
+
+    def assert_example_does_not_raise(self):
+        with tempfile.TemporaryDirectory(
+            prefix=f"build123d_test_examples_{name}"
+        ) as tmpdir:
+            mock_ocp_vscode = Path(tmpdir) / "_mock_ocp_vscode.py"
+            with open(mock_ocp_vscode, "w", encoding="utf-8") as f:
+                f.write(_MOCK_OCP_VSCODE_CONTENTS)
+            got = subprocess.run(
+                [
+                    sys.executable,
+                    "-c",
+                    f"exec(open('{mock_ocp_vscode}').read()); exec(open('{path}').read())",
+                ],
+                capture_output=True,
+                cwd=tmpdir,
+                check=False,
+            )
+            self.assertEqual(
+                0, got.returncode, f"stdout/stderr: {got.stdout} / {got.stderr}"
+            )
+
+    return assert_example_does_not_raise
+
+
+class TestExamples(unittest.TestCase):
+    """Tests build123d examples."""
+
+
+for example in sorted(_examples_dir.iterdir()):
+    if example.name.startswith("_"):
+        continue
+    setattr(
+        TestExamples,
+        f"test_{example.name.replace('.', '_')}",
+        generate_example_test(example),
+    )
+
+if __name__ == "__main__":
+    unittest.main()