split stdout and stderr, remove output check after self.assertRaises(SystemExit)

Author: ggqlq

Lib/test/test_httpservers.py

@@ -1569,11 +1569,12 @@ def setUp(self):
         self.addCleanup(os_helper.unlink, self.tls_password_file)
 
     def invoke_httpd(self, *args):
-        output = StringIO()
-        with contextlib.redirect_stdout(output), \
-            contextlib.redirect_stderr(output):
+        stdout = StringIO()
+        stderr = StringIO()
+        with contextlib.redirect_stdout(stdout), \
+            contextlib.redirect_stderr(stderr):
             server._main(args)
-        return output.getvalue()
+        return {'stdout': stdout.getvalue(), 'stderr': stderr.getvalue()}
 
     @mock.patch('http.server.test')
     def test_port_flag(self, mock_func):
@@ -1703,14 +1704,11 @@ def test_help_flag(self, _):
         for option in options:
             with self.assertRaises(SystemExit):
                 output = self.invoke_httpd(option)
-            self.assertStartsWith(output, 'usage: ')
 
     @mock.patch('http.server.test')
     def test_unknown_flag(self, _):
         with self.assertRaises(SystemExit):
             output = self.invoke_httpd('--unknown-flag')
-        self.assertStartsWith(output, 'usage: ')
-
 
 class CommandLineRunTimeTestCase(unittest.TestCase):
     random_data = os.urandom(1024)