def test_factor_with_parens(self):
lexer = Lexer('(3)')
parser = Parser(lexer)
result = parser.factor()
expected = Num(Token('INTEGER', 3))
assert result == expected
def test_factor_error(self):
lexer = Lexer('+')
parser = Parser(lexer)
with pytest.raises(SyntaxError) as ex:
parser.factor()
assert 'Invalid syntax' == str(ex.value)
