diff --git a/tests/unit/miniscord/test_bot.py b/tests/unit/miniscord/test_bot.py
index f2eb339..399f0cb 100644
--- a/tests/unit/miniscord/test_bot.py
+++ b/tests/unit/miniscord/test_bot.py
@@ -1,6 +1,6 @@
 from unittest import TestCase, skip
-from unittest.mock import Mock, MagicMock, AsyncMock
-from tests.utils import AsyncTestCase
+from unittest.mock import AsyncMock
+from tests.utils import AsyncTestCase, patch_discord
 
 import discord
 from datetime import datetime
@@ -8,8 +8,8 @@ from miniscord._bot import Bot
 
 
 class TestInit(TestCase):
+    @patch_discord
     def test_normal(self):
-        discord.Client = Mock()
         bot = Bot("app_name", "version")
         self.assertEqual("app_name", bot.app_name)
         self.assertEqual("version", bot.version)
@@ -18,8 +18,8 @@ class TestInit(TestCase):
         self.assertEqual(2, len(bot._Bot__commands))
         self.assertEqual(2, len(bot.games))
 
+    @patch_discord
     def test_alias(self):
-        discord.Client = Mock()
         bot = Bot("app_name", "version", alias="alias")
         self.assertEqual("app_name", bot.app_name)
         self.assertEqual("version", bot.version)
@@ -30,8 +30,8 @@ class TestInit(TestCase):
 
 
 class TestInfo(AsyncTestCase):
+    @patch_discord
     def test(self):
-        discord.Client = Mock()
         bot = Bot("app_name", "version")
         message = AsyncMock()
         t0 = datetime.now()
@@ -48,8 +48,8 @@ class TestInfo(AsyncTestCase):
 
 
 class TestHelp(AsyncTestCase):
+    @patch_discord
     def test_list_minimal(self):
-        discord.Client = Mock()
         bot = Bot("app_name", "version")
         message = AsyncMock()
         self._await(bot.help(None, message, "help"))
@@ -61,8 +61,8 @@ class TestHelp(AsyncTestCase):
             f"```"
         )
 
+    @patch_discord
     def test_list_alias(self):
-        discord.Client = Mock()
         bot = Bot("app_name", "version", alias="¡")
         message = AsyncMock()
         self._await(bot.help(None, message, "help"))
@@ -74,8 +74,8 @@ class TestHelp(AsyncTestCase):
             f"```"
         )
 
+    @patch_discord
     def test_list_functions(self):
-        discord.Client = Mock()
         bot = Bot("app_name", "version")
         bot.register_command("", None, "test1: desc1", None)
         bot.register_command("", None, "test2: desc2", None)
@@ -91,16 +91,16 @@ class TestHelp(AsyncTestCase):
             f"```"
         )
 
+    @patch_discord
     def test_long(self):
-        discord.Client = Mock()
         bot = Bot("app_name", "version")
         bot.register_command("test1", None, None, "long desc")
         message = AsyncMock()
         self._await(bot.help(None, message, "help", "test1"))
         message.channel.send.assert_awaited_once_with("long desc")
 
+    @patch_discord
     def test_long_regex(self):
-        discord.Client = Mock()
         bot = Bot("app_name", "version")
         bot.register_command("test", None, None, "desc1")
         bot.register_command("t.*", None, None, "desc2")
@@ -110,9 +110,28 @@ class TestHelp(AsyncTestCase):
 
 
 class TestRegisterCommand(TestCase):
-    @skip
-    def test_todo(self):
-        self.fail("not implemented")
+    @patch_discord
+    def test_normal(self):
+        bot = Bot("app_name", "version")
+        self.assertEqual(2, len(bot._Bot__commands))
+
+        def fn():
+            pass
+
+        bot.register_command("^t[eo]a?st$", fn, "short", "long")
+        self.assertEqual(3, len(bot._Bot__commands))
+        cmd = bot._Bot__commands[0]
+        self.assertEqual("^t[eo]a?st$", cmd.regex)
+        self.assertEqual(fn, cmd.compute)
+        self.assertEqual("short", cmd.help_short)
+        self.assertEqual("long", cmd.help_long)
+
+    @patch_discord
+    def test_add_regex(self):
+        bot = Bot("app_name", "version")
+        bot.register_command("test", None, None, None)
+        cmd = bot._Bot__commands[0]
+        self.assertEqual("^test$", cmd.regex)
 
 
 class TestOnMessage(AsyncTestCase):
@@ -128,12 +147,30 @@ class TestOnReady(AsyncTestCase):
 
 
 class TestOnGuildJoin(AsyncTestCase):
+    @patch_discord
+    def test_no_log(self):
+        bot = Bot("app_name", "version")
+        bot.guild_logs_file = None
+        guild = AsyncMock()
+        self._await(bot.on_guild_join(guild))
+        # nothing
+        # TODO test normal file path
+
     @skip
-    def test_todo(self):
+    def test_log(self):
         self.fail("not implemented")
 
 
 class TestOnGuildRemove(AsyncTestCase):
+    @patch_discord
+    def test_no_log(self):
+        bot = Bot("app_name", "version")
+        bot.guild_logs_file = None
+        guild = AsyncMock()
+        self._await(bot.on_guild_remove(guild))
+        # nothing
+        # TODO test normal file path
+
     @skip
-    def test_todo(self):
+    def test_log(self):
         self.fail("not implemented")
diff --git a/tests/utils.py b/tests/utils.py
index 299555d..99f9e57 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -1,4 +1,5 @@
 from unittest import TestCase
+from unittest.mock import MagicMock, patch
 import asyncio
 
 
@@ -12,3 +13,17 @@ class AsyncTestCase(TestCase):
 
     def _await(self, fn):
         return self.loop.run_until_complete(fn)
+
+
+def pass_through(arg):
+    return arg
+
+
+def patch_discord(test):
+    def wrapper(*args):
+        m = MagicMock()
+        m.event = pass_through
+        with patch("discord.Client", return_value=m):
+            test(*args)
+
+    return wrapper