iotests: add testing shim for script-style python tests

Because the new-style python tests don't use the iotests.main() test
launcher, we don't turn on the debugger logging for these scripts
when invoked via ./check -d.

Refactor the launcher shim into new and old style shims so that they
share environmental configuration.

Two cleanup notes: debug was not actually used as a global, and there
was no reason to create a class in an inner scope just to achieve
default variables; we can simply create an instance of the runner with
the values we want instead.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190709232550.10724-14-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

tests/qemu-iotests/iotests.py

@@ -61,7 +61,6 @@
 qemu_default_machine = os.environ.get('QEMU_DEFAULT_MACHINE')
 
 socket_scm_helper = os.environ.get('SOCKET_SCM_HELPER', 'socket_scm_helper')
-debug = False
 
 luks_default_secret_object = 'secret,id=keysec0,data=' + \
                              os.environ.get('IMGKEYSECRET', '')
@@ -858,11 +857,22 @@ def func_wrapper(*args, **kwargs):
         return func_wrapper
     return skip_test_decorator
 
-def main(supported_fmts=[], supported_oses=['linux'], supported_cache_modes=[],
-         unsupported_fmts=[]):
-    '''Run tests'''
+def execute_unittest(output, verbosity, debug):
+    runner = unittest.TextTestRunner(stream=output, descriptions=True,
+                                     verbosity=verbosity)
+    try:
+        # unittest.main() will use sys.exit(); so expect a SystemExit
+        # exception
+        unittest.main(testRunner=runner)
+    finally:
+        if not debug:
+            sys.stderr.write(re.sub(r'Ran (\d+) tests? in [\d.]+s',
+                                    r'Ran \1 tests', output.getvalue()))
 
-    global debug
+def execute_test(test_function=None,
+                 supported_fmts=[], supported_oses=['linux'],
+                 supported_cache_modes=[], unsupported_fmts=[]):
+    """Run either unittest or script-style tests."""
 
     # We are using TEST_DIR and QEMU_DEFAULT_MACHINE as proxies to
     # indicate that we're not being run via "check". There may be
@@ -894,13 +904,15 @@ def main(supported_fmts=[], supported_oses=['linux'], supported_cache_modes=[],
 
     logging.basicConfig(level=(logging.DEBUG if debug else logging.WARN))
 
-    class MyTestRunner(unittest.TextTestRunner):
-        def __init__(self, stream=output, descriptions=True, verbosity=verbosity):
-            unittest.TextTestRunner.__init__(self, stream, descriptions, verbosity)
+    if not test_function:
+        execute_unittest(output, verbosity, debug)
+    else:
+        test_function()
 
-    # unittest.main() will use sys.exit() so expect a SystemExit exception
-    try:
-        unittest.main(testRunner=MyTestRunner)
-    finally:
-        if not debug:
-            sys.stderr.write(re.sub(r'Ran (\d+) tests? in [\d.]+s', r'Ran \1 tests', output.getvalue()))
+def script_main(test_function, *args, **kwargs):
+    """Run script-style tests outside of the unittest framework"""
+    execute_test(test_function, *args, **kwargs)
+
+def main(*args, **kwargs):
+    """Run tests using the unittest framework"""
+    execute_test(None, *args, **kwargs)