Issue #22002: Make full use of test discovery in test sub-packages.

Adds `load_package_tests` function to test.support, uses it in test_asyncio,
test_email, test_json, test_tools, test_importlib and all test_importlib
sub-packages to implement test discovery.

2 files changed, 8 insertions, 12 deletions

diff --git a/Lib/test/test_importlib/extension/__init__.py b/Lib/test/test_importlib/extension/__init__.py
index c033923..4b16ecc 100644
--- a/Lib/test/test_importlib/extension/__init__.py
+++ b/Lib/test/test_importlib/extension/__init__.py
@@ -1,13 +1,5 @@
-from .. import test_suite
-import os.path
-import unittest
+import os
+from test.support import load_package_tests
 
-
-def test_suite():
-    directory = os.path.dirname(__file__)
-    return test_suite('importlib.test.extension', directory)
-
-
-if __name__ == '__main__':
-    from test.support import run_unittest
-    run_unittest(test_suite())
+def load_tests(*args):
+    return load_package_tests(os.path.dirname(__file__), *args)
diff --git a/Lib/test/test_importlib/extension/__main__.py b/Lib/test/test_importlib/extension/__main__.py
new file mode 100644
index 0000000..40a23a2
--- /dev/null
+++ b/Lib/test/test_importlib/extension/__main__.py
@@ -0,0 +1,4 @@
+from . import load_tests
+import unittest
+
+unittest.main()