bpo-40280: Detect missing threading on WASM platforms (GH-32352)

Co-authored-by: Brett Cannon <brett@python.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/Lib/test/support/threading_helper.py b/Lib/test/support/threading_helper.py
index 2ae4577..7b636f0 100644
--- a/Lib/test/support/threading_helper.py
+++ b/Lib/test/support/threading_helper.py
@@ -4,6 +4,7 @@ import functools
 import sys
 import threading
 import time
+import unittest
 
 from test import support
 
@@ -210,7 +211,7 @@ class catch_threading_exception:
 
 
 def _can_start_thread() -> bool:
-    """Detect if Python can start new threads.
+    """Detect whether Python can start new threads.
 
     Some WebAssembly platforms do not provide a working pthread
     implementation. Thread support is stubbed and any attempt
@@ -234,3 +235,15 @@ def _can_start_thread() -> bool:
         return True
 
 can_start_thread = _can_start_thread()
+
+def requires_working_threading(*, module=False):
+    """Skip tests or modules that require working threading.
+
+    Can be used as a function/class decorator or to skip an entire module.
+    """
+    msg = "requires threading support"
+    if module:
+        if not can_start_thread:
+            raise unittest.SkipTest(msg)
+    else:
+        return unittest.skipUnless(can_start_thread, msg)