ruby - 提高ArgumentError ruby

Question

我有一个简单的骰子类(class)。如何测试ArgumentError？

 class Die
   def initialize(num)
    if num < 1
      raise(ArgumentError)
    end
    @num = num
  end
  def sides
    return @sides
  end

  def roll
    @value = rand(@num) + 1
    return @value
  end
end

这是我失败的尝试。

assert_raise ArgumentError do
  zero = 0
  die = Die.new(zero)
  puts die.sides == raise(ArgumentError)
end

Answer 1

此实现应帮助您断言是否引发错误:

class TestDie < MiniTest::Unit::TestCase 
  def test_argument_error
    assert_raises ArgumentError do
      Die.new(0)
    end
  end

  def test_argument_error_not_raised
    refute_raises ArgumentError do
      Die.new(2)
    end
  end
end  

要拒绝不应引发异常，可以编写类似于以下内容的自己的refute_raises方法:

def refute_raises
  yield
rescue Exception => err
  flunk "Expected no failures but #{mu_pp(err).chomp} was raised."
end

assert_raises和 flunk的文档