diff --git a/src/ytdl_sub/script/parser.py b/src/ytdl_sub/script/parser.py
index 6ed6a1df..32f4ed19 100644
--- a/src/ytdl_sub/script/parser.py
+++ b/src/ytdl_sub/script/parser.py
@@ -1,4 +1,3 @@
-from contextlib import contextmanager
 from enum import Enum
 from typing import Dict
 from typing import List
@@ -16,9 +15,9 @@ from ytdl_sub.script.types.resolvable import String
 from ytdl_sub.script.types.syntax_tree import SyntaxTree
 from ytdl_sub.script.types.variable import FunctionArgument
 from ytdl_sub.script.types.variable import Variable
+from ytdl_sub.script.utils.exceptions import UNREACHABLE
 from ytdl_sub.script.utils.exceptions import IncompatibleFunctionArguments
 from ytdl_sub.script.utils.exceptions import InvalidSyntaxException
-from ytdl_sub.script.utils.exceptions import UnreachableSyntaxException
 from ytdl_sub.script.utils.exceptions import UserException
 from ytdl_sub.script.utils.parser_exception_formatter import ParserExceptionFormatter
 from ytdl_sub.utils.exceptions import StringFormattingException
@@ -35,12 +34,6 @@ class ArgumentParser(Enum):
     MAP_VALUE = "map value"
 
 
-UNREACHABLE = UnreachableSyntaxException(
-    "If you see this error, you have discovered a bug in the script parser!\n"
-    "Please upload your config/subscription file(s) to and make a GitHub issue at "
-    "https://github.com/jmbannon/ytdl-sub/issues"
-)
-
 BRACKET_NOT_CLOSED = InvalidSyntaxException("Bracket not properly closed")
 
 NUMERICS_ONLY_ARGS = InvalidSyntaxException(
diff --git a/src/ytdl_sub/script/types/function.py b/src/ytdl_sub/script/types/function.py
index b6ca5632..dce5e6ee 100644
--- a/src/ytdl_sub/script/types/function.py
+++ b/src/ytdl_sub/script/types/function.py
@@ -23,6 +23,7 @@ from ytdl_sub.script.types.resolvable import Resolvable
 from ytdl_sub.script.types.variable import FunctionArgument
 from ytdl_sub.script.types.variable import Variable
 from ytdl_sub.script.types.variable_dependency import VariableDependency
+from ytdl_sub.script.utils.exceptions import UNREACHABLE
 from ytdl_sub.script.utils.exceptions import IncompatibleFunctionArguments
 from ytdl_sub.utils.exceptions import StringFormattingException
 
@@ -113,10 +114,10 @@ class FunctionInputSpec:
     def is_compatible(self, input_args: List[ArgumentType]) -> bool:
         if self.args is not None:
             return self._is_args_compatible(input_args=input_args)
-        elif self.varargs is not None:
+        if self.varargs is not None:
             return self._is_varargs_compatible(input_args=input_args)
-        else:
-            assert False, "should never reach here"
+
+        raise UNREACHABLE  # TODO: functions with no args
 
     def expected_args_str(self) -> str:
         def to_human_readable_name(python_type: Type[NamedType] | Type[Union[NamedType]]) -> str:
@@ -128,8 +129,9 @@ class FunctionInputSpec:
 
         if self.args is not None:
             return f"({', '.join([to_human_readable_name(type_) for type_ in self.args])})"
-        elif self.varargs is not None:
+        if self.varargs is not None:
             return f"({to_human_readable_name(self.varargs.__name__)}, ...)"
+        return "()"
 
     @classmethod
     def from_function(cls, func: "BuiltInFunction") -> "FunctionInputSpec":
@@ -233,7 +235,7 @@ class BuiltInFunction(Function):
             else:
                 received_type_names.append(arg.type_name())
 
-        received_args_str = f"({', '.join([name for name in received_type_names])})"
+        received_args_str = f"({', '.join(name for name in received_type_names)})"
 
         return f"Expected {self.input_spec.expected_args_str()}\nReceived {received_args_str}"
 
diff --git a/src/ytdl_sub/script/utils/exceptions.py b/src/ytdl_sub/script/utils/exceptions.py
index 75522c01..f62b5382 100644
--- a/src/ytdl_sub/script/utils/exceptions.py
+++ b/src/ytdl_sub/script/utils/exceptions.py
@@ -17,3 +17,10 @@ class IncompatibleFunctionArguments(UserException):
 
 class UnreachableSyntaxException(InvalidSyntaxException):
     """For use in places where code _should_ never reach, but might from bugs"""
+
+
+UNREACHABLE = UnreachableSyntaxException(
+    "If you see this error, you have discovered a bug in the script parser!\n"
+    "Please upload your config/subscription file(s) to and make a GitHub issue at "
+    "https://github.com/jmbannon/ytdl-sub/issues"
+)
diff --git a/tests/unit/script/test_parser.py b/tests/unit/script/test_parser.py
index 2ee26a9e..d0e1d8e1 100644
--- a/tests/unit/script/test_parser.py
+++ b/tests/unit/script/test_parser.py
@@ -34,29 +34,6 @@ class TestParser:
             ]
         )
 
-    # def test_array(self):
-    #     parsed = parse("hello {['elem1', 'elem2']}")
-    #     parsed_empty = parse("hello {[]}")
-    #     parsed_with_var = parse("hello {['elem1', variable_name]}")
-    #     parsed_extend = parse(
-    #         "hi {%at(%flatten_array(%extend(['elem1', 'elem2'], ['elem3'], [['elem4'], ['elem5', 'elem6']],   ['elem7'])), 1)}"
-    #     )
-    #     parsed_extend.resolve({})
-    #     assert False
-    #
-    # def test_map(self):
-    #     parsed = parse("hello {%map(['elem1', 'elem2'])}")
-    #     parsed_empty = parse("hello {%map()}")
-    #     parsed_with_var = parse("hello {%map([variable_name, 'elem2'])}")
-    #     parsed_extend = parse("hi {%map([variable_name, 'elem2'], ['elem3', variable_name])}")
-    #     parse_raw_map = parse("hello {{'key': 'value'}}")
-    #     parsed_extend.resolve({})
-    #     assert False
-    #
-    # def test_function_argument(self):
-    #     parsed = parse("hello {%map([$1, $2])}")
-    #     assert False
-
     def test_conditional(self):
         parsed = parse("hello {%if(True, 'hi', 3.4)}")
         assert parsed == SyntaxTree(
diff --git a/tests/unit/script/types/test_bool.py b/tests/unit/script/types/test_bool.py
index ee6a3fd6..96d9378b 100644
--- a/tests/unit/script/types/test_bool.py
+++ b/tests/unit/script/types/test_bool.py
@@ -1,19 +1,10 @@
 import re
-from typing import Tuple
 
 import pytest
 
 from ytdl_sub.script.parser import BOOLEAN_ONLY_ARGS
-from ytdl_sub.script.parser import NUMERICS_INVALID_CHAR
-from ytdl_sub.script.parser import NUMERICS_ONLY_ARGS
-from ytdl_sub.script.parser import UNEXPECTED_CHAR_ARGUMENT
-from ytdl_sub.script.parser import UNEXPECTED_COMMA_ARGUMENT
-from ytdl_sub.script.parser import ArgumentParser
 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 Float
-from ytdl_sub.script.types.resolvable import Integer
 from ytdl_sub.script.types.resolvable import String
 from ytdl_sub.script.utils.exceptions import InvalidSyntaxException
 
diff --git a/tests/unit/script/types/test_float.py b/tests/unit/script/types/test_float.py
index 8d2c97bd..763d7453 100644
--- a/tests/unit/script/types/test_float.py
+++ b/tests/unit/script/types/test_float.py
@@ -1,18 +1,12 @@
 import re
-from typing import Tuple
 
 import pytest
 
 from ytdl_sub.script.parser import NUMERICS_INVALID_CHAR
 from ytdl_sub.script.parser import NUMERICS_ONLY_ARGS
-from ytdl_sub.script.parser import UNEXPECTED_CHAR_ARGUMENT
-from ytdl_sub.script.parser import UNEXPECTED_COMMA_ARGUMENT
-from ytdl_sub.script.parser import ArgumentParser
 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 Float
-from ytdl_sub.script.types.resolvable import Integer
 from ytdl_sub.script.types.resolvable import String
 from ytdl_sub.script.utils.exceptions import InvalidSyntaxException
 
diff --git a/tests/unit/script/types/test_function.py b/tests/unit/script/types/test_function.py
index 1fa41238..e8cd5ed1 100644
--- a/tests/unit/script/types/test_function.py
+++ b/tests/unit/script/types/test_function.py
@@ -1,22 +1,11 @@
 import re
-from typing import Tuple
 
 import pytest
 
-from ytdl_sub.script.parser import NUMERICS_INVALID_CHAR
-from ytdl_sub.script.parser import NUMERICS_ONLY_ARGS
-from ytdl_sub.script.parser import STRINGS_ONLY_ARGS
-from ytdl_sub.script.parser import UNEXPECTED_CHAR_ARGUMENT
-from ytdl_sub.script.parser import UNEXPECTED_COMMA_ARGUMENT
-from ytdl_sub.script.parser import ArgumentParser
 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 Float
-from ytdl_sub.script.types.resolvable import Integer
 from ytdl_sub.script.types.resolvable import String
 from ytdl_sub.script.utils.exceptions import IncompatibleFunctionArguments
-from ytdl_sub.script.utils.exceptions import InvalidSyntaxException
 
 
 def _incompatible_arguments_match(expected: str, recieved: str) -> str:
diff --git a/tests/unit/script/types/test_integer.py b/tests/unit/script/types/test_integer.py
index 02ed5055..e696c0eb 100644
--- a/tests/unit/script/types/test_integer.py
+++ b/tests/unit/script/types/test_integer.py
@@ -1,17 +1,11 @@
 import re
-from typing import Tuple
 
 import pytest
 
 from ytdl_sub.script.parser import NUMERICS_INVALID_CHAR
 from ytdl_sub.script.parser import NUMERICS_ONLY_ARGS
-from ytdl_sub.script.parser import UNEXPECTED_CHAR_ARGUMENT
-from ytdl_sub.script.parser import UNEXPECTED_COMMA_ARGUMENT
-from ytdl_sub.script.parser import ArgumentParser
 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 Float
 from ytdl_sub.script.types.resolvable import Integer
 from ytdl_sub.script.types.resolvable import String
 from ytdl_sub.script.utils.exceptions import InvalidSyntaxException
diff --git a/tests/unit/script/types/test_string.py b/tests/unit/script/types/test_string.py
index d0aa4df4..3b37fac9 100644
--- a/tests/unit/script/types/test_string.py
+++ b/tests/unit/script/types/test_string.py
@@ -1,20 +1,11 @@
 import re
-from typing import Tuple
 
 import pytest
 
-from ytdl_sub.script.parser import NUMERICS_INVALID_CHAR
-from ytdl_sub.script.parser import NUMERICS_ONLY_ARGS
 from ytdl_sub.script.parser import STRINGS_NOT_CLOSED
 from ytdl_sub.script.parser import STRINGS_ONLY_ARGS
-from ytdl_sub.script.parser import UNEXPECTED_CHAR_ARGUMENT
-from ytdl_sub.script.parser import UNEXPECTED_COMMA_ARGUMENT
-from ytdl_sub.script.parser import ArgumentParser
 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 Float
-from ytdl_sub.script.types.resolvable import Integer
 from ytdl_sub.script.types.resolvable import String
 from ytdl_sub.script.utils.exceptions import InvalidSyntaxException