test

src/ytdl_sub/script/script.py

@@ -71,16 +71,17 @@ class Script:
         ):
             for dep in self._functions[custom_func.name].variables:
                 self._ensure_no_cycle(
-                    name=variable_name, dep=dep.name, deps=deps, definitions=self._variables
+                    name=variable_name,
+                    dep=dep.name,
+                    deps=deps + [custom_func.definition_name()],
+                    definitions=self._variables,
                 )
                 self._traverse_variable_dependencies(
                     variable_name=variable_name,
                     variable_dependency=self._variables[dep.name],
-                    deps=deps + [dep.name],
+                    deps=deps + [custom_func.definition_name(), dep.name],
                 )
 
-
-
     def _ensure_no_variable_cycles(self, variables: Dict[str, SyntaxTree]):
         for variable_name, variable_definition in variables.items():
             self._traverse_variable_dependencies(

src/ytdl_sub/script/types/resolvable.py

@@ -193,6 +193,14 @@ class NamedCustomFunction(NamedArgument, ABC):
 class ParsedCustomFunction(NamedCustomFunction):
     num_input_args: int
 
+    def definition_name(self) -> str:
+        """
+        Returns
+        -------
+        The function definition name, including the %
+        """
+        return f"%{self.name}"
+
 
 @dataclass(frozen=True)
 class FunctionType(NamedArgument, ABC):

src/ytdl_sub/script/types/variable_dependency.py

@@ -163,6 +163,17 @@ class VariableDependency(ABC):
     def custom_function_dependencies(
         self, custom_function_definitions: Dict[str, "VariableDependency"]
     ) -> Set[ParsedCustomFunction]:
+        """
+        Parameters
+        ----------
+        custom_function_definitions
+            Definition of all currently existing custom functions. Needed to check whether
+            a lambda function's input function is custom or not.
+
+        Returns
+        -------
+        All custom function dependencies
+        """
         custom_functions = self.custom_functions
         for lambda_func in self.lambdas:
             if lambda_func.value in custom_function_definitions:

tests/unit/script/types/test_lambda_function.py

@@ -6,6 +6,7 @@ from ytdl_sub.script.script import Script
 from ytdl_sub.script.script_output import ScriptOutput
 from ytdl_sub.script.types.array import Array
 from ytdl_sub.script.types.resolvable import Integer
+from ytdl_sub.script.utils.exceptions import CycleDetected
 from ytdl_sub.script.utils.exceptions import IncompatibleFunctionArguments
 
 
@@ -169,3 +170,10 @@ class TestLambdaFunctionIncompatibleNumArguments:
                     "%output": f"{{%array_enumerate(array1, {lambda_value})}}",
                 }
             )
+
+    def test_lambda_with_custom_function_cycle(self):
+        with pytest.raises(
+            CycleDetected,
+            match=re.escape("Cycle detected within these variables: two -> %times_two -> two"),
+        ):
+            Script({"%times_two": "{%mul($0, two)}", "two": "{%times_two(2)}"})