def test_multiply_operator(self):
interpreter = Interpreter('')
self.assertEqual(4, interpreter.evaluate_expression(2, MULTIPLY, 2))
def test_return_eof_token_when_out_of_bounds(self):
interpreter = Interpreter('')
self.assertEqual(Token(EOF, None).type, interpreter.get_next_token().type)
def test_divide_operator(self):
interpreter = Interpreter('')
self.assertEqual(2, interpreter.evaluate_expression(4, DIVIDE, 2))
def test_subtract_operator(self):
interpreter = Interpreter('')
self.assertEqual(1, interpreter.evaluate_expression(2, SUBTRACT, 1))
def test_plus_operator(self):
interpreter = Interpreter('')
self.assertEqual(2, interpreter.evaluate_expression(1, PLUS, 1))
def test_invalid_token_raises_exception(self):
interpreter = Interpreter('')
interpreter.current_token = Token(PLUS, '+')
with self.assertRaises(InvalidTokenException) as exc:
interpreter.eat([DIVIDE, MULTIPLY])
def test_valid_token_calls_get_next_token(self):
interpreter = Interpreter('')
with patch.object(interpreter, 'get_next_token') as get_next_token:
interpreter.current_token = Token(PLUS, '+')
interpreter.eat([PLUS, SUBTRACT, DIVIDE, MULTIPLY])
self.assertTrue(get_next_token.called)