Don't try to execute a test-command when it doesn't look like a module

Author: joerick

cibuildwheel/platforms/ios.py

@@ -596,19 +596,36 @@ def build(options: Options, tmp_path: Path) -> None:
 
                     test_command_parts = shlex.split(build_options.test_command)
                     if test_command_parts[0:2] != ["python", "-m"]:
-                        log.warning(
-                            unwrap_preserving_paragraphs(f"""
-                                iOS tests configured with a test command which doesn't start with
-                                'python -m'. iOS tests must execute python modules - other
-                                entrypoints are not supported.
-
-                                cibuildwheel will try to execute it as if it started with 'python
-                                -m'. If this works, all you need to do is add that to your test
-                                command.
-
-                                Test command: {build_options.test_command}
-                            """)
+                        first_part = test_command_parts[0]
+                        first_arg_looks_like_a_module_name = all(
+                            n.isidentifier() for n in first_part.split(".")
                         )
+                        if first_arg_looks_like_a_module_name:
+                            log.warning(
+                                unwrap_preserving_paragraphs(f"""
+                                    iOS tests configured with a test command which doesn't start
+                                    with 'python -m'. iOS tests must execute python modules - other
+                                    entrypoints are not supported.
+
+                                    cibuildwheel will try to execute it as if it started with
+                                    'python -m'. If this works, all you need to do is add that to
+                                    your test command.
+
+                                    Test command: {build_options.test_command}
+                                """)
+                            )
+                        else:
+                            # no point in trying to run it as a module - it's not a module
+                            msg = unwrap_preserving_paragraphs(
+                                f"""
+                                    iOS tests configured with a test command which doesn't start
+                                    with 'python -m'. iOS tests must execute python modules - other
+                                    entrypoints are not supported.
+
+                                    Test command: {build_options.test_command}
+                                """
+                            )
+                            raise errors.FatalError(msg)
                     else:
                         # the testbed run command actually doesn't want the
                         # python -m prefix - it's implicit, so we remove it

test/test_ios.py

@@ -249,3 +249,29 @@ def test_ios_test_command_without_python_dash_m(tmp_path, capfd):
     out, err = capfd.readouterr()
 
     assert "iOS tests configured with a test command which doesn't start with 'python -m'" in err
+
+
+def test_ios_test_command_invalid(tmp_path, capfd):
+    """Test command should raise an error if it's clearly invalid."""
+    if utils.platform != "macos":
+        pytest.skip("this test can only run on macOS")
+    if utils.get_xcode_version() < (13, 0):
+        pytest.skip("this test only works with Xcode 13.0 or greater")
+
+    project_dir = tmp_path / "project"
+    basic_project = test_projects.new_c_project()
+    basic_project.files["./my_test_script.sh"] = "echo hello"
+    basic_project.generate(project_dir)
+
+    with pytest.raises(subprocess.CalledProcessError):
+        utils.cibuildwheel_run(
+            project_dir,
+            add_env={
+                "CIBW_PLATFORM": "ios",
+                "CIBW_TEST_COMMAND": "./my_test_script.sh",
+                "CIBW_TEST_SOURCES": "./my_test_script.sh",
+                "CIBW_XBUILD_TOOLS": "",
+            },
+        )
+    out, err = capfd.readouterr()
+    assert "iOS tests configured with a test command which doesn't start with 'python -m'" in err