[BACKEND] Validate override variable names (#845)

Validate as early as possible whether override names are invalid, to prevent confusing downstream errors

src/ytdl_sub/config/overrides.py

@@ -11,6 +11,7 @@ from ytdl_sub.entries.variables.override_variables import SUBSCRIPTION_NAME
 from ytdl_sub.entries.variables.override_variables import OverrideVariables
 from ytdl_sub.script.parser import parse
 from ytdl_sub.script.script import Script
+from ytdl_sub.utils.exceptions import InvalidVariableNameException
 from ytdl_sub.utils.exceptions import ValidationException
 from ytdl_sub.utils.script import ScriptUtils
 from ytdl_sub.utils.scriptable import Scriptable
@@ -86,16 +87,26 @@ class Overrides(DictFormatterValidator, Scriptable):
         """
         Ensures the variable name does not collide with any entry variables or built-in functions.
         """
+        if not OverrideVariables.is_valid_name(name):
+            override_type = "function" if name.startswith("%") else "variable"
+            raise self._validation_exception(
+                f"Override {override_type} with name {name} is invalid. Names must be"
+                " lower_snake_cased and begin with a letter.",
+                exception_class=InvalidVariableNameException,
+            )
+
         if OverrideVariables.is_entry_variable_name(name):
             raise self._validation_exception(
                 f"Override variable with name {name} cannot be used since it is a"
-                " built-in ytdl-sub entry variable name."
+                " built-in ytdl-sub entry variable name.",
+                exception_class=InvalidVariableNameException,
             )
 
         if OverrideVariables.is_function_name(name):
             raise self._validation_exception(
                 f"Override function definition with name {name} cannot be used since it is"
-                " a built-in ytdl-sub function name."
+                " a built-in ytdl-sub function name.",
+                exception_class=InvalidVariableNameException,
             )
 
     def initial_variables(

src/ytdl_sub/entries/variables/override_variables.py

@@ -1,6 +1,7 @@
 from ytdl_sub.entries.script.function_scripts import CUSTOM_FUNCTION_SCRIPTS
 from ytdl_sub.entries.script.variable_scripts import VARIABLE_SCRIPTS
 from ytdl_sub.script.functions import Functions
+from ytdl_sub.script.utils.name_validation import is_valid_name
 
 SUBSCRIPTION_NAME = "subscription_name"
 SUBSCRIPTION_VALUE = "subscription_value"
@@ -81,3 +82,15 @@ class OverrideVariables:
         if name.startswith("%"):
             return name in CUSTOM_FUNCTION_SCRIPTS or Functions.is_built_in(name[1:])
         return False
+
+    @classmethod
+    def is_valid_name(cls, name: str) -> bool:
+        """
+        Returns
+        -------
+        True if the override name itself is valid. False otherwise.
+        """
+        if name.startswith("%"):
+            return is_valid_name(name=name[1:])
+
+        return is_valid_name(name=name)

src/ytdl_sub/validators/source_variable_validator.py

@@ -1,5 +1,5 @@
+from ytdl_sub.script.utils.name_validation import is_valid_name
 from ytdl_sub.utils.exceptions import InvalidVariableNameException
-from ytdl_sub.validators.string_formatter_validators import is_valid_source_variable_name
 from ytdl_sub.validators.validators import ListValidator
 from ytdl_sub.validators.validators import StringValidator
 
@@ -9,10 +9,13 @@ class SourceVariableNameValidator(StringValidator):
 
     def __init__(self, name, value):
         super().__init__(name, value)
-        try:
-            _ = is_valid_source_variable_name(self.value, raise_exception=True)
-        except InvalidVariableNameException as exc:
-            raise self._validation_exception(exc) from exc
+
+        if not is_valid_name(value):
+            raise self._validation_exception(
+                f"Variable with name {name} is invalid. Names must be"
+                " lower_snake_cased and begin with a letter.",
+                exception_class=InvalidVariableNameException,
+            )
 
 
 class SourceVariableNameListValidator(ListValidator[SourceVariableNameValidator]):

src/ytdl_sub/validators/string_formatter_validators.py

@@ -1,4 +1,3 @@
-import re
 from typing import Dict
 from typing import Set
 from typing import Union
@@ -9,7 +8,6 @@ from ytdl_sub.script.parser import parse
 from ytdl_sub.script.script import Script
 from ytdl_sub.script.utils.exceptions import UserException
 from ytdl_sub.script.utils.exceptions import VariableDoesNotExist
-from ytdl_sub.utils.exceptions import InvalidVariableNameException
 from ytdl_sub.utils.exceptions import StringFormattingVariableNotFoundException
 from ytdl_sub.validators.validators import DictValidator
 from ytdl_sub.validators.validators import ListValidator
@@ -17,38 +15,6 @@ from ytdl_sub.validators.validators import LiteralDictValidator
 from ytdl_sub.validators.validators import StringValidator
 from ytdl_sub.validators.validators import Validator
 
-_fields_validator = re.compile(r"{([a-z][a-z0-9_]*?)}")
-
-_fields_validator_exception_message: str = (
-    "{variable_names} must start with a lowercase letter, should only contain lowercase letters, "
-    "numbers, underscores, and have a single open and close bracket."
-)
-
-
-def is_valid_source_variable_name(input_str: str, raise_exception: bool = False) -> bool:
-    """
-    Parameters
-    ----------
-    input_str
-        String to see if it can be a source variable
-    raise_exception
-        Raise InvalidVariableNameException False.
-
-    Returns
-    -------
-    True if it is. False otherwise.
-
-    Raises
-    ------
-    InvalidVariableNameException
-        If raise_exception and output is False
-    """
-    # Add brackets around it to pretend its a StringFormatter, see if it captures
-    is_source_variable_name = len(re.findall(_fields_validator, f"{{{input_str}}}")) > 0
-    if not is_source_variable_name and raise_exception:
-        raise InvalidVariableNameException(_fields_validator_exception_message)
-    return is_source_variable_name
-
 
 class StringFormatterValidator(StringValidator):
     """

tests/unit/config/test_preset.py

@@ -334,6 +334,33 @@ class TestPreset:
                 },
             )
 
+    @pytest.mark.parametrize(
+        "name", ["!ack", "*asfsaf", "1234352", "--234asdf", "___asdf", "1asdfasdfasd"]
+    )
+    @pytest.mark.parametrize("is_function", [True, False])
+    def test_preset_error_overrides_invalid_variable_name(
+        self, config_file, youtube_video, output_options, name: str, is_function: bool
+    ):
+        name_type = "function" if is_function else "variable"
+        name = f"%{name}" if is_function else name
+
+        with pytest.raises(
+            ValidationException,
+            match=re.escape(
+                f"Override {name_type} with name {name} is invalid."
+                " Names must be lower_snake_cased and begin with a letter."
+            ),
+        ):
+            _ = Preset(
+                config=config_file,
+                name="test",
+                value={
+                    "download": youtube_video,
+                    "output_options": output_options,
+                    "overrides": {name: "ack"},
+                },
+            )
+
     def test_preset_error_added_url_variable_cannot_resolve(self, config_file, output_options):
         with pytest.raises(
             ValidationException,

tests/unit/plugins/test_regex_capture.py

@@ -1 +0,0 @@
-