variable dne proper message

src/ytdl_sub/script/parser.py

@@ -27,6 +27,7 @@ from ytdl_sub.script.utils.exceptions import FunctionDoesNotExist
 from ytdl_sub.script.utils.exceptions import IncompatibleFunctionArguments
 from ytdl_sub.script.utils.exceptions import InvalidSyntaxException
 from ytdl_sub.script.utils.exceptions import UserException
+from ytdl_sub.script.utils.exceptions import VariableDoesNotExist
 from ytdl_sub.utils.exceptions import StringFormattingException
 from ytdl_sub.validators.string_formatter_validators import is_valid_source_variable_name
 
@@ -163,6 +164,7 @@ class _Parser:
 
     def _parse_variable(self) -> Variable:
         var_name = ""
+        variable_start_pos = self._pos
         while ch := self._read(increment_pos=False):
             if ch.isspace() and not var_name:
                 self._pos += 1
@@ -183,7 +185,13 @@ class _Parser:
         if not var_name:
             raise StringFormattingException("invalid var name")
 
-        assert is_valid_source_variable_name(var_name, raise_exception=False)
+        if not is_valid_source_variable_name(var_name, raise_exception=False):
+            raise UNREACHABLE
+
+        if self._variable_names is not None and var_name not in self._variable_names:
+            self._set_highlight_position(variable_start_pos)
+            raise VariableDoesNotExist(f"Variable {var_name} does not exist.")
+
         return Variable(var_name)
 
     def _parse_custom_function_argument(self) -> FunctionArgument:

src/ytdl_sub/script/script.py

@@ -9,7 +9,6 @@ from ytdl_sub.script.types.syntax_tree import SyntaxTree
 from ytdl_sub.script.types.variable import Variable
 from ytdl_sub.script.utils.exceptions import UNREACHABLE
 from ytdl_sub.script.utils.exceptions import CycleDetected
-from ytdl_sub.script.utils.exceptions import VariableDoesNotExist
 
 # pylint: disable=missing-raises-doc
 
@@ -41,9 +40,7 @@ class Script:
     ) -> None:
         for dep in variable_dependency.variables:
             if dep.name not in self._variables:
-                raise VariableDoesNotExist(
-                    f"{variable_name} uses the variable {dep.name} which does not exist."
-                )
+                continue  # does not exist, will throw downstream in parser
 
             if variable_name in deps + [dep.name]:
                 cycle_deps = [variable_name] + deps + [dep.name]
@@ -72,7 +69,7 @@ class Script:
     ) -> None:
         for dep in custom_function_dependency.custom_functions:
             if dep.name not in self._functions:
-                continue  # does not exist, will throw downstream
+                continue  # does not exist, will throw downstream in parser
 
             if custom_function_name in deps + [dep.name]:
                 cycle_deps = [custom_function_name] + deps + [dep.name]

src/ytdl_sub/script/types/function.py

@@ -27,7 +27,6 @@ from ytdl_sub.script.types.variable import Variable
 from ytdl_sub.script.types.variable_dependency import VariableDependency
 from ytdl_sub.script.utils.exception_formatters import FunctionArgumentsExceptionFormatter
 from ytdl_sub.script.utils.exceptions import UNREACHABLE
-from ytdl_sub.script.utils.exceptions import FunctionDoesNotExist
 from ytdl_sub.script.utils.exceptions import FunctionRuntimeException
 from ytdl_sub.script.utils.exceptions import UserThrownRuntimeError
 from ytdl_sub.script.utils.type_checking import FunctionInputSpec

tests/unit/script/types/test_variable.py

@@ -47,6 +47,6 @@ class TestVariable:
     def test_undefined_variable(self):
         with pytest.raises(
             VariableDoesNotExist,
-            match=re.escape("b uses the variable c which does not exist."),
+            match=re.escape("Variable c does not exist."),
         ):
             Script({"a": "a", "b": "{c}"}).resolve()