diff --git a/aiogram/utils/helper.py b/aiogram/utils/helper.py
index a7725f3e..67400511 100644
--- a/aiogram/utils/helper.py
+++ b/aiogram/utils/helper.py
@@ -79,7 +79,7 @@ class HelperMode(Helper):
     @classmethod
     def _snake_case(cls, text):
         """
-        Transform text to snake cale (Based on SCREAMING_SNAKE_CASE)
+        Transform text to snake case (Based on SCREAMING_SNAKE_CASE)
 
         :param text:
         :return:
diff --git a/tests/utils/__init__.py b/tests/test_utils/__init__.py
similarity index 100%
rename from tests/utils/__init__.py
rename to tests/test_utils/__init__.py
diff --git a/tests/test_utils/test_helper.py b/tests/test_utils/test_helper.py
new file mode 100644
index 00000000..5477917e
--- /dev/null
+++ b/tests/test_utils/test_helper.py
@@ -0,0 +1,127 @@
+import pytest
+from aiogram.utils.helper import Helper, HelperMode, Item, ListItem, OrderedHelper
+
+
+class TestHelper:
+    def test_items_all(self):
+        class MyHelper(Helper):
+            A = Item()
+            B = Item()
+            C = Item()
+            D = Item()
+
+        assert set(MyHelper.all()) == {"A", "B", "C", "D"}
+
+    def test_listed_items_all(self):
+        class MyHelper(Helper):
+            A = ListItem()
+            B = ListItem()
+            C = ListItem()
+            D = ListItem()
+
+        assert set(MyHelper.all()) == {"A", "B", "C", "D"}
+
+    def test_listed_items_combinations(self):
+        class MyHelper(Helper):
+            A = ListItem()
+            B = ListItem()
+            C = ListItem()
+            D = ListItem()
+
+        assert (MyHelper.A | MyHelper.B) == ["A", "B"]
+        assert (MyHelper.C & MyHelper.D) == ["C", "D"]
+        assert MyHelper.A.add(MyHelper.D) == ["A", "D"]
+        assert MyHelper.B + MyHelper.D == ["B", "D"]
+
+    def test_wrong_name(self):
+        with pytest.raises(RuntimeError):
+
+            class MyHelper(Helper):
+                kaboom = Item()
+
+
+class TestHelperMode:
+    def test_helper_mode_all(self):
+        assert set(HelperMode.all()) == {
+            "SCREAMING_SNAKE_CASE",
+            "lowerCamelCase",
+            "CamelCase",
+            "snake_case",
+            "lowercase",
+        }
+
+    def test_screaming_snake_case(self):
+        class MyHelper(Helper):
+            mode = HelperMode.SCREAMING_SNAKE_CASE
+
+            FOO = Item()
+            BAR_BAZ = Item()
+
+        assert MyHelper.FOO == "FOO"
+        assert MyHelper.BAR_BAZ == "BAR_BAZ"
+
+    def test_lower_camel_case(self):
+        class MyHelper(Helper):
+            mode = HelperMode.lowerCamelCase
+
+            FOO = Item()
+            BAR_BAZ = Item()
+
+        assert MyHelper.FOO == "foo"
+        assert MyHelper.BAR_BAZ == "barBaz"
+
+    def test_camel_case(self):
+        class MyHelper(Helper):
+            mode = HelperMode.CamelCase
+
+            FOO = Item()
+            BAR_BAZ = Item()
+
+        assert MyHelper.FOO == "Foo"
+        assert MyHelper.BAR_BAZ == "BarBaz"
+
+    def test_snake_case(self):
+        class MyHelper(Helper):
+            mode = HelperMode.snake_case
+
+            FOO = Item()
+            BAR_BAZ = Item()
+
+        assert MyHelper.FOO == "foo"
+        assert MyHelper.BAR_BAZ == "bar_baz"
+
+    def test_lowercase(self):
+        class MyHelper(Helper):
+            mode = HelperMode.lowercase
+
+            FOO = Item()
+            BAR_BAZ = Item()
+
+        assert MyHelper.FOO == "foo"
+        assert MyHelper.BAR_BAZ == "barbaz"
+
+    def test_extended_converters(self):
+        assert HelperMode.apply("test_text", mode=HelperMode.SCREAMING_SNAKE_CASE) == "TEST_TEXT"
+        assert HelperMode.apply("TestText", mode=HelperMode.SCREAMING_SNAKE_CASE) == "TEST_TEXT"
+        assert HelperMode.apply("test_text", mode=HelperMode.snake_case) == "test_text"
+        assert HelperMode.apply("foo", mode=lambda m: m.upper()) == "FOO"
+
+
+class TestOrderedHelper:
+    def test_items_are_ordered(self):
+        class MyOrderedHelper(OrderedHelper):
+            A = Item()
+            D = Item()
+            C = Item()
+            B = Item()
+
+        assert MyOrderedHelper.all() == ["A", "D", "C", "B"]
+
+    def test_list_items_are_ordered(self):
+        class MyOrderedHelper(OrderedHelper):
+            A = ListItem()
+            D = ListItem()
+            C = ListItem()
+            B = ListItem()
+
+        assert MyOrderedHelper.all() == ["A", "D", "C", "B"]
diff --git a/tests/test_utils/test_mixins.py b/tests/test_utils/test_mixins.py
new file mode 100644
index 00000000..720bd38e
--- /dev/null
+++ b/tests/test_utils/test_mixins.py
@@ -0,0 +1,51 @@
+import pytest
+from aiogram.utils.mixins import ContextInstanceMixin, DataMixin
+
+
+class DataObject(DataMixin):
+    pass
+
+
+class ContextObject(ContextInstanceMixin):
+    pass
+
+
+class TestDataMixin:
+    def test_store_value(self):
+        obj = DataObject()
+        obj["foo"] = 42
+
+        assert "foo" in obj
+        assert obj["foo"] == 42
+        assert len(obj.data) == 1
+
+    def test_remove_value(self):
+        obj = DataObject()
+        obj["foo"] = 42
+        del obj["foo"]
+
+        assert "key" not in obj
+        assert len(obj.data) == 0
+
+    def test_getter(self):
+        obj = DataObject()
+        obj["foo"] = 42
+
+        assert obj.get("foo") == 42
+        assert obj.get("bar") is None
+        assert obj.get("baz", "test") == "test"
+
+
+class TestContextInstanceMixin:
+    def test_empty(self):
+        obj = ContextObject()
+
+        assert obj.get_current(no_error=True) is None
+        with pytest.raises(LookupError):
+            assert obj.get_current(no_error=False)
+
+    def test_set_wrong_type(self):
+        obj = ContextObject()
+
+        with pytest.raises(TypeError, match=r"Value should be instance of 'ContextObject' not '.+'"):
+            obj.set_current(42)
diff --git a/tests/utils/test_mixins.py b/tests/utils/test_mixins.py
deleted file mode 100644
index c2141127..00000000
--- a/tests/utils/test_mixins.py
+++ /dev/null
@@ -1,36 +0,0 @@
-from aiogram.utils.mixins import DataMixin
-
-
-class MyClass(DataMixin):
-    pass
-
-
-class TestDataMixin:
-    def test_store_value(self):
-        obj = MyClass()
-        obj["foo"] = 42
-
-        assert "foo" in obj
-        assert obj["foo"] == 42
-        assert len(obj.data) == 1
-
-    def test_remove_value(self):
-        obj = MyClass()
-        obj["foo"] = 42
-        del obj["foo"]
-
-        assert "key" not in obj
-        assert len(obj.data) == 0
-
-    def test_getter(self):
-        obj = MyClass()
-        obj["foo"] = 42
-
-        assert obj.get("foo") == 42
-        assert obj.get("bar") is None
-        assert obj.get("baz", "test") == "test"
-
-
-class TestContextInstanceMixin:
-    def test_instance(self):
-        pass