diff --git a/tests/unit/script/types/test_custom_function.py b/tests/unit/script/types/test_custom_function.py
new file mode 100644
index 00000000..10a5bb63
--- /dev/null
+++ b/tests/unit/script/types/test_custom_function.py
@@ -0,0 +1,111 @@
+import re
+
+import pytest
+
+from ytdl_sub.script.script import Script
+from ytdl_sub.script.types.array import ResolvedArray
+from ytdl_sub.script.types.resolvable import Integer
+from ytdl_sub.script.utils.exceptions import CycleDetected
+
+
+class TestCustomFunction:
+    def test_custom_function_use_input_param_multiple_times(self):
+        assert Script(
+            {
+                "%custom_square": "{%mul($0, $0)}",
+                "output": "{%custom_square(3)}",
+            }
+        ).resolve() == {"output": Integer(9)}
+
+    def test_custom_function_cycle(self):
+        with pytest.raises(
+            CycleDetected, match=re.escape("The custom function %cycle_func cannot call itself.")
+        ):
+            Script(
+                {"%cycle_func": "{%mul(%cycle_func(1), $0)}", "output": "{%cycle_func(1)}"}
+            ).resolve()
+
+    def test_custom_function_chained_cycle(self):
+        with pytest.raises(
+            CycleDetected,
+            match=re.escape(
+                "Custom functions contain a cycle: %cycle_func1 -> %cycle_func0 -> %cycle_func1"
+            ),
+        ):
+            Script(
+                {
+                    "%cycle_func1": "{%mul(%cycle_func0(1), $0)}",
+                    "%cycle_func0": "{%mul(%cycle_func1(1), $0)}",
+                    "output": "{%cycle_func0(1)}",
+                }
+            ).resolve()
+
+    def test_custom_function_deep_chained_cycle(self):
+        with pytest.raises(
+            CycleDetected,
+            match=re.escape(
+                "Custom functions contain a cycle: "
+                "%cycle_func4 -> "
+                "%cycle_func0 -> "
+                "%cycle_func1 -> "
+                "%cycle_func2 -> "
+                "%cycle_func3 -> "
+                "%cycle_func4"
+            ),
+        ):
+            Script(
+                {
+                    "%nested_safe_func": "{%mul($0, 1)}",
+                    "%safe_func": "{%nested_safe_func($0, 1)}",
+                    "%cycle_func4": "{%mul(%cycle_func0(1), %safe_func($0))}",
+                    "%cycle_func3": "{%mul(%cycle_func4(1), %safe_func($0))}",
+                    "%cycle_func2": "{%mul(%cycle_func3(1), %safe_func($0))}",
+                    "%cycle_func1": "{%mul(%cycle_func2(1), %safe_func($0))}",
+                    "%cycle_func0": "{%mul(%cycle_func1(1), %safe_func($0))}",
+                    "output": "{%cycle_func0(1)}",
+                }
+            ).resolve()
+
+    def test_lambda_with_custom_function(self):
+        assert Script(
+            {"%times_two": "{%mul($0, 2)}", "wip": "{%array_apply([1, 2, 3], %times_two)}"}
+        ).resolve() == {"wip": ResolvedArray([Integer(2), Integer(4), Integer(6)])}
+
+    def test_conditional_lambda_with_custom_functions(self):
+        assert Script(
+            {
+                "%times_three": "{%mul($0, 3)}",
+                "%times_two": "{%mul($0, 2)}",
+                "wip": "{%array_apply([1, 2, 3], %if(False, %times_two, %times_three))}",
+            }
+        ).resolve() == {"wip": ResolvedArray([Integer(3), Integer(6), Integer(9)])}
+
+    def test_nested_custom_functions(self):
+        assert Script(
+            {
+                "%times_three": "{%mul($0, 3)}",
+                "%times_two": "{%mul($0, 2)}",
+                "identity": "{%times_three(%times_two(1))}",
+            }
+        ).resolve() == {"identity": Integer(6)}
+
+    def test_nested_custom_functions_within_custom_functions(self):
+        assert Script(
+            {
+                "%power_2": "{%mul($0, 2)}",
+                "%power_3": "{%mul(%power_2($0), 2)}",
+                "%power_4": "{%mul(%power_3($0), 2)}",
+                "power_of_4": "{%power_4(2)}",
+            }
+        ).resolve() == {"power_of_4": Integer(16)}
+
+    def test_nested_lambda_custom_functions_within_custom_functions(self):
+        assert Script(
+            {
+                "%nest4": "{%mul($0, 2)}",
+                "%nest3": "{%array_at(%array_apply([$0], %nest4), 0)}",
+                "%nest2": "{%array_at(%array_apply([$0], %nest3), 0)}",
+                "%nest1": "{%array_at(%array_apply([$0], %nest2), 0)}",
+                "output": "{%array_at(%array_apply([2], %nest1), 0)}",
+            }
+        ).resolve() == {"output": Integer(4)}
diff --git a/tests/unit/script/types/test_function.py b/tests/unit/script/types/test_function.py
index eb560bb5..0f3e6997 100644
--- a/tests/unit/script/types/test_function.py
+++ b/tests/unit/script/types/test_function.py
@@ -4,11 +4,8 @@ import pytest
 
 from ytdl_sub.script.parser import FUNCTION_INVALID_CHAR
 from ytdl_sub.script.script import Script
-from ytdl_sub.script.types.array import ResolvedArray
 from ytdl_sub.script.types.resolvable import Boolean
-from ytdl_sub.script.types.resolvable import Integer
 from ytdl_sub.script.types.resolvable import String
-from ytdl_sub.script.utils.exceptions import CycleDetected
 from ytdl_sub.script.utils.exceptions import FunctionDoesNotExist
 from ytdl_sub.script.utils.exceptions import FunctionRuntimeException
 from ytdl_sub.script.utils.exceptions import IncompatibleFunctionArguments
@@ -117,104 +114,3 @@ class TestFunction:
             match=re.escape(str(FUNCTION_INVALID_CHAR)),
         ):
             Script({"dne": "{%throw}"}).resolve()
-
-    def test_custom_function_use_input_param_multiple_times(self):
-        assert Script(
-            {
-                "%custom_square": "{%mul($0, $0)}",
-                "output": "{%custom_square(3)}",
-            }
-        ).resolve() == {"output": Integer(9)}
-
-    def test_custom_function_cycle(self):
-        with pytest.raises(
-            CycleDetected, match=re.escape("The custom function %cycle_func cannot call itself.")
-        ):
-            Script(
-                {"%cycle_func": "{%mul(%cycle_func(1), $0)}", "output": "{%cycle_func(1)}"}
-            ).resolve()
-
-    def test_custom_function_chained_cycle(self):
-        with pytest.raises(
-            CycleDetected,
-            match=re.escape(
-                "Custom functions contain a cycle: %cycle_func1 -> %cycle_func0 -> %cycle_func1"
-            ),
-        ):
-            Script(
-                {
-                    "%cycle_func1": "{%mul(%cycle_func0(1), $0)}",
-                    "%cycle_func0": "{%mul(%cycle_func1(1), $0)}",
-                    "output": "{%cycle_func0(1)}",
-                }
-            ).resolve()
-
-    def test_custom_function_deep_chained_cycle(self):
-        with pytest.raises(
-            CycleDetected,
-            match=re.escape(
-                "Custom functions contain a cycle: "
-                "%cycle_func4 -> "
-                "%cycle_func0 -> "
-                "%cycle_func1 -> "
-                "%cycle_func2 -> "
-                "%cycle_func3 -> "
-                "%cycle_func4"
-            ),
-        ):
-            Script(
-                {
-                    "%nested_safe_func": "{%mul($0, 1)}",
-                    "%safe_func": "{%nested_safe_func($0, 1)}",
-                    "%cycle_func4": "{%mul(%cycle_func0(1), %safe_func($0))}",
-                    "%cycle_func3": "{%mul(%cycle_func4(1), %safe_func($0))}",
-                    "%cycle_func2": "{%mul(%cycle_func3(1), %safe_func($0))}",
-                    "%cycle_func1": "{%mul(%cycle_func2(1), %safe_func($0))}",
-                    "%cycle_func0": "{%mul(%cycle_func1(1), %safe_func($0))}",
-                    "output": "{%cycle_func0(1)}",
-                }
-            ).resolve()
-
-    def test_lambda_with_custom_function(self):
-        assert Script(
-            {"%times_two": "{%mul($0, 2)}", "wip": "{%array_apply([1, 2, 3], %times_two)}"}
-        ).resolve() == {"wip": ResolvedArray([Integer(2), Integer(4), Integer(6)])}
-
-    def test_conditional_lambda_with_custom_functions(self):
-        assert Script(
-            {
-                "%times_three": "{%mul($0, 3)}",
-                "%times_two": "{%mul($0, 2)}",
-                "wip": "{%array_apply([1, 2, 3], %if(False, %times_two, %times_three))}",
-            }
-        ).resolve() == {"wip": ResolvedArray([Integer(3), Integer(6), Integer(9)])}
-
-    def test_nested_custom_functions(self):
-        assert Script(
-            {
-                "%times_three": "{%mul($0, 3)}",
-                "%times_two": "{%mul($0, 2)}",
-                "identity": "{%times_three(%times_two(1))}",
-            }
-        ).resolve() == {"identity": Integer(6)}
-
-    def test_nested_custom_functions_within_custom_functions(self):
-        assert Script(
-            {
-                "%power_2": "{%mul($0, 2)}",
-                "%power_3": "{%mul(%power_2($0), 2)}",
-                "%power_4": "{%mul(%power_3($0), 2)}",
-                "power_of_4": "{%power_4(2)}",
-            }
-        ).resolve() == {"power_of_4": Integer(16)}
-
-    def test_nested_lambda_custom_functions_within_custom_functions(self):
-        assert Script(
-            {
-                "%nest4": "{%mul($0, 2)}",
-                "%nest3": "{%array_at(%array_apply([$0], %nest4), 0)}",
-                "%nest2": "{%array_at(%array_apply([$0], %nest3), 0)}",
-                "%nest1": "{%array_at(%array_apply([$0], %nest2), 0)}",
-                "output": "{%array_at(%array_apply([2], %nest1), 0)}",
-            }
-        ).resolve() == {"output": Integer(4)}
diff --git a/tests/unit/script/types/test_lambda_function.py b/tests/unit/script/types/test_lambda_function.py
new file mode 100644
index 00000000..f010d033
--- /dev/null
+++ b/tests/unit/script/types/test_lambda_function.py
@@ -0,0 +1,49 @@
+from ytdl_sub.script.script import Script
+from ytdl_sub.script.types.array import ResolvedArray
+from ytdl_sub.script.types.resolvable import Integer
+
+
+class TestLambdaFunction:
+    def test_lambda_with_custom_function(self):
+        assert Script(
+            {"%times_two": "{%mul($0, 2)}", "wip": "{%array_apply([1, 2, 3], %times_two)}"}
+        ).resolve() == {"wip": ResolvedArray([Integer(2), Integer(4), Integer(6)])}
+
+    def test_conditional_lambda_with_custom_functions(self):
+        assert Script(
+            {
+                "%times_three": "{%mul($0, 3)}",
+                "%times_two": "{%mul($0, 2)}",
+                "wip": "{%array_apply([1, 2, 3], %if(False, %times_two, %times_three))}",
+            }
+        ).resolve() == {"wip": ResolvedArray([Integer(3), Integer(6), Integer(9)])}
+
+    def test_nested_custom_functions(self):
+        assert Script(
+            {
+                "%times_three": "{%mul($0, 3)}",
+                "%times_two": "{%mul($0, 2)}",
+                "identity": "{%times_three(%times_two(1))}",
+            }
+        ).resolve() == {"identity": Integer(6)}
+
+    def test_nested_custom_functions_within_custom_functions(self):
+        assert Script(
+            {
+                "%power_2": "{%mul($0, 2)}",
+                "%power_3": "{%mul(%power_2($0), 2)}",
+                "%power_4": "{%mul(%power_3($0), 2)}",
+                "power_of_4": "{%power_4(2)}",
+            }
+        ).resolve() == {"power_of_4": Integer(16)}
+
+    def test_nested_lambda_custom_functions_within_custom_functions(self):
+        assert Script(
+            {
+                "%nest4": "{%mul($0, 2)}",
+                "%nest3": "{%array_at(%array_apply([$0], %nest4), 0)}",
+                "%nest2": "{%array_at(%array_apply([$0], %nest3), 0)}",
+                "%nest1": "{%array_at(%array_apply([$0], %nest2), 0)}",
+                "output": "{%array_at(%array_apply([2], %nest1), 0)}",
+            }
+        ).resolve() == {"output": Integer(4)}