Question

如何使用Rspec模拟推送到类数组变量？这是一个过于简化的例子：

class Foo
  attr_accessor :bar
  def initialize
    @bar = []
  end
end

def some_method(foo)
  foo.bar << "a"
end

假设我想为some_method编写一个规范，“它应该将新值推送到bar”。我该怎么做？

foo = Foo.new
foo.should_receive(WHAT GOES HERE???).with("a")
some_method(foo)

Answer 1

为什么要嘲笑？当你试图与实际尝试测试的东西隔离时，你只需要模拟一些东西。在您的情况下，您似乎正在尝试验证调用some_method会导致将项添加到您传入的对象的属性中。您可以直接测试它：

foo = Foo.new
some_method(foo)
foo.bar.should == ["a"]

foo2 = Foo.new
foo2.bar = ["z", "q"]
some_method(foo2)
foo2.bar.should == ["z", "q", "a"]

# TODO: Cover situation when foo.bar is nil since it is available as attr_accessor 
# and can be set from outside of the instance

*在以下评论后编辑**

foo = Foo.new
bar = mock
foo.should_receive(:bar).and_return bar
bar.should_receive(:<<).with("a")
some_method(foo)

Answer 2

来自docs的示例： http://rubydoc.info/gems/rspec-mocks/frames

double.should_receive(:<<).with("illegal value").once.and_raise(ArgumentError)

如何使用Rspec模拟数组推送

2 个答案: