EH Tests: Remove class member `cog` + other small changes

- Added `assertIsNone` to `test_error_handler_already_handled`.
- Removed `ErrorHandlerTests.cog`, moved it to each test recreation.

1 files changed, 15 insertions, 14 deletions

diff --git a/tests/bot/cogs/test_error_handler.py b/tests/bot/cogs/test_error_handler.py
index 510c66b29..3945bbb90 100644
--- a/tests/bot/cogs/test_error_handler.py
+++ b/tests/bot/cogs/test_error_handler.py
@@ -13,13 +13,13 @@ class ErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
     def setUp(self):
         self.bot = MockBot()
         self.ctx = MockContext(bot=self.bot)
-        self.cog = ErrorHandler(self.bot)
 
     async def test_error_handler_already_handled(self):
         """Should not do anything when error is already handled by local error handler."""
+        cog = ErrorHandler(self.bot)
         error = errors.CommandError()
         error.handled = "foo"
-        await self.cog.on_command_error(self.ctx, error)
+        self.assertIsNone(await cog.on_command_error(self.ctx, error))
         self.ctx.send.assert_not_awaited()
 
     async def test_error_handler_command_not_found_error_not_invoked_by_handler(self):
@@ -42,30 +42,31 @@ class ErrorHandlerTests(unittest.IsolatedAsyncioTestCase):
                 "called_try_get_tag": True
             }
         )
-        self.cog.try_silence = AsyncMock()
-        self.cog.try_get_tag = AsyncMock()
+        cog = ErrorHandler(self.bot)
+        cog.try_silence = AsyncMock()
+        cog.try_get_tag = AsyncMock()
 
         for case in test_cases:
             with self.subTest(try_silence_return=case["try_silence_return"], try_get_tag=case["called_try_get_tag"]):
                 self.ctx.reset_mock()
-                self.cog.try_silence.reset_mock(return_value=True)
-                self.cog.try_get_tag.reset_mock()
+                cog.try_silence.reset_mock(return_value=True)
+                cog.try_get_tag.reset_mock()
 
-                self.cog.try_silence.return_value = case["try_silence_return"]
+                cog.try_silence.return_value = case["try_silence_return"]
                 self.ctx.channel.id = 1234
 
                 if case["patch_verification_id"]:
                     with patch("bot.cogs.error_handler.Channels.verification", new=1234):
-                        self.assertIsNone(await self.cog.on_command_error(self.ctx, error))
+                        self.assertIsNone(await cog.on_command_error(self.ctx, error))
                 else:
-                    self.assertIsNone(await self.cog.on_command_error(self.ctx, error))
+                    self.assertIsNone(await cog.on_command_error(self.ctx, error))
                 if case["try_silence_return"]:
-                    self.cog.try_get_tag.assert_not_awaited()
-                    self.cog.try_silence.assert_awaited_once()
+                    cog.try_get_tag.assert_not_awaited()
+                    cog.try_silence.assert_awaited_once()
                 else:
-                    self.cog.try_silence.assert_awaited_once()
+                    cog.try_silence.assert_awaited_once()
                     if case["patch_verification_id"]:
-                        self.cog.try_get_tag.assert_not_awaited()
+                        cog.try_get_tag.assert_not_awaited()
                     else:
-                        self.cog.try_get_tag.assert_awaited_once()
+                        cog.try_get_tag.assert_awaited_once()
                 self.ctx.send.assert_not_awaited()