README.md

Stub return values

# create a double
obj = double()

# specify a return value
obj.stub(:message) { :value }
obj.stub(:message => :value)
obj.stub(:message).and_return(:value)

These forms are somewhat interchangeable. The difference is that the block contents are evaluated lazily when the obj receives the message message, whereas the others are evaluated as they are read.

Fake implementation

obj.stub(:message) do |arg1, arg2|
  # set expectations about the args in this block
  # and/or set a return value
end

Raising/Throwing

obj.stub(:message).and_raise("this error")
obj.stub(:message).and_throw(:this_symbol)

You can also use the block format:

obj.stub(:message) { raise "this error" }
obj.stub(:message) { throw :this_symbol }

Argument constraints

Explicit arguments

obj.stub(:message).with('an argument') { ... }
obj.stub(:message).with('more_than', 'one_argument') { ... }

Argument matchers

obj.stub(:message).with(anything()) { ... }
obj.stub(:message).with(an_instance_of(Money)) { ... }
obj.stub(:message).with(hash_including(:a => 'b')) { ... }

Regular expressions

obj.stub(:message).with(/abc/) { ... }