test: add import tests

Author: XuehaiPan

tests/concurrent/test_subinterpreters.py

@@ -14,6 +14,8 @@
 # ==============================================================================
 
 import atexit
+import importlib
+import re
 import sys
 
 import pytest
@@ -26,10 +28,16 @@
 )
 
 
-if PYPY or WASM or sys.version_info < (3, 14):
+if (
+    PYPY
+    or WASM
+    or sys.version_info < (3, 14)
+    or not getattr(sys.implementation, 'supports_isolated_interpreters', False)
+):
     pytest.skip('Test for CPython 3.14+ only', allow_module_level=True)
 
 
+from concurrent import interpreters
 from concurrent.futures import InterpreterPoolExecutor, as_completed
 
 
@@ -64,3 +72,29 @@ def concurrent_run(func, /, *args, **kwargs):
 
 
 run(object)  # warm-up
+
+
+def test_import_failure():
+    sub_interpreter = interpreters.create()
+
+    with pytest.raises(
+        ImportError,
+        match=re.escape('module optree._C does not support loading in subinterpreters'),
+    ) as excinfo:
+        run(importlib.import_module, 'optree')
+
+    with pytest.raises(
+        interpreters.ExecutionFailed,
+        match=re.escape('module optree._C does not support loading in subinterpreters'),
+    ) as excinfo:
+        sub_interpreter.call(importlib.import_module, 'optree')
+    assert excinfo.value.excinfo.type.__name__ == 'ImportError'
+
+    with pytest.raises(
+        interpreters.ExecutionFailed,
+        match=re.escape('module optree._C does not support loading in subinterpreters'),
+    ) as excinfo:
+        sub_interpreter.exec('import optree')
+    assert excinfo.value.excinfo.type.__name__ == 'ImportError'
+
+    sub_interpreter.close()