test_enable_devtools and remove redundant guards for None and "" which was there due to a bug

Author: abhinavsingh

proxy/proxy.py

@@ -412,8 +412,7 @@ def load_plugins(
         }
         for plugin_ in plugins:
             klass, module_name = Proxy.import_plugin(plugin_)
-            if klass is None and module_name is None:
-                continue
+            assert klass and module_name
             mro = list(inspect.getmro(klass))
             mro.reverse()
             iterator = iter(mro)
@@ -432,8 +431,7 @@ def import_plugin(plugin: Union[bytes, type]) -> Any:
             klass = plugin
         else:
             plugin_ = text_(plugin.strip())
-            if plugin_ == '':
-                return (None, None)
+            assert plugin_ != ''
             module_name, klass_name = plugin_.rsplit(text_(DOT), 1)
             klass = getattr(
                 importlib.import_module(
@@ -449,8 +447,9 @@ def import_plugin(plugin: Union[bytes, type]) -> Any:
     def get_default_plugins(
             args: argparse.Namespace,
     ) -> List[str]:
-        # Prepare list of plugins to load based upon
-        # --enable-*, --disable-* and --basic-auth flags.
+        """Prepare list of plugins to load based upon
+        --enable-*, --disable-* and --basic-auth flags.
+        """
         default_plugins: List[str] = []
         if args.basic_auth is not None:
             default_plugins.append(PLUGIN_PROXY_AUTH)
@@ -514,7 +513,7 @@ def main(
             # at runtime.  Example, updating flags, plugin
             # configuration etc.
             #
-            # TODO: Python shell within running proxy.py environment
+            # TODO: Python shell within running proxy.py environment?
             while True:
                 time.sleep(1)
     except KeyboardInterrupt:

tests/test_main.py

@@ -177,6 +177,39 @@ def test_enable_dashboard(
         mock_event_manager.return_value.start_event_dispatcher.assert_called_once()
         mock_event_manager.return_value.stop_event_dispatcher.assert_called_once()
 
+    @mock.patch('time.sleep')
+    @mock.patch('proxy.proxy.Proxy.load_plugins')
+    @mock.patch('proxy.common.flag.FlagParser.parse_args')
+    @mock.patch('proxy.proxy.EventManager')
+    @mock.patch('proxy.proxy.AcceptorPool')
+    def test_enable_devtools(
+        self,
+        mock_acceptor_pool: mock.Mock,
+        mock_event_manager: mock.Mock,
+        mock_parse_args: mock.Mock,
+        mock_load_plugins: mock.Mock,
+        mock_sleep: mock.Mock,
+    ) -> None:
+        mock_sleep.side_effect = KeyboardInterrupt()
+        mock_args = mock_parse_args.return_value
+        self.mock_default_args(mock_args)
+        mock_args.enable_devtools = True
+        main(['--enable-devtools'])
+        mock_load_plugins.assert_called()
+        print(mock_load_plugins.call_args_list[0][0][0])
+        self.assertEqual(
+            mock_load_plugins.call_args_list[0][0][0], [
+                b'proxy.http.inspector.DevtoolsProtocolPlugin',
+                b'proxy.http.server.HttpWebServerPlugin',
+                b'proxy.http.proxy.HttpProxyPlugin',
+            ],
+        )
+        mock_parse_args.assert_called_once()
+        mock_acceptor_pool.assert_called()
+        mock_acceptor_pool.return_value.setup.assert_called()
+        # Currently --enable-devtools alone doesn't enable eventing core
+        mock_event_manager.assert_not_called()
+
     @mock.patch('time.sleep')
     @mock.patch('os.remove')
     @mock.patch('os.path.exists')
@@ -284,14 +317,11 @@ def test_main_version(
             mock_print.assert_called_with(__version__)
         self.assertEqual(e.exception.code, 0)
 
-    def test_enable_devtools(self) -> None:
-        pass
-
-    def test_pac_file(self) -> None:
-        pass
+    # def test_pac_file(self) -> None:
+    #     pass
 
-    def test_imports_plugin(self) -> None:
-        pass
+    # def test_imports_plugin(self) -> None:
+    #     pass
 
-    def test_cannot_enable_https_proxy_and_tls_interception_mutually(self) -> None:
-        pass
+    # def test_cannot_enable_https_proxy_and_tls_interception_mutually(self) -> None:
+    #     pass