ruby - Is it possible to have an rspec double with a default response? -

i want mock object might receive number of messages don't care about. i'd object have default answer, such 'true', ability add specific methods , answers matter. possible in rspec? i'd this:

obj = default_double(default: true, widget_count: 5) obj.foobar.should == true obj.widget_count.should == 5 

it'd nice if pass in lambda or proc return value , have default_double return evaluation of lambda. extra-nice if proc or lambda evaluated in context of test, access variables available in example.

so if features above added, might have like:

@widgets = widgetcontainer.new @widgets.widget_count = 5 obj = default_double(default: true, widget_count: lambda { @widgets.widget_count }) obj.foobar.should == true obj.widget_count.should == 5 

if motivation feature interesting reader, let's assume either don't want dig , find out possible messages receive, or set of possible messages extremely large or unknown.

is built in rspec?

ok, i'll take shot @ answering question:

i believe rspec not have built-in mock capability receive arbitrary message , return default value. however, allow specify return value block which, along ruby's method_missing feature, should allow readily construct default_double method describe above.

here's cut @ passes above example, although benefit refactoring:

require 'spec_helper'  def default_double(args)   object = object.new   args.each |key, value|     if key == :default       object.define_singleton_method(:method_missing) { |method, *args, &block| value }     elsif proc === value       expect(object).to receive(key) value.call end     else expect(object).to receive(key).and_return(value)     end   end   object end  class widgetcontainer   attr_accessor :widget_count end  describe "default_double test"   "should pass"     @widgets = widgetcontainer.new     @widgets.widget_count = 5     obj = default_double(default: true, widget_count: lambda { @widgets.widget_count })     obj.foobar.should == true     obj.widget_count.should == 5   end end