ruby on rails - Mock a class's local method -

i trying write test case in rpec class this

class abc    def method_1( arg )        #does , return value based on arg    end     def initialize        @service = method_1( arg )    end     def getsomething_1        return @service.get_seomthing_1    end     def getsomething_2        return @service.get_seomthing_2    end end 

now want initiate @service instance variable mocked object can use mocked object return values against can validate unit tests.

i tried like

describe abc     before(:each)        myobject = double()        myobject.stub(:get_something_1).and_return("somevalue")        abc.any_instance.stub(:method_1).and_return(myobject)     end     "checks correctness of getsomething_1 method of class abc"        @abc = abc.new        @abc.getsomething_1.should eql("somevalue")    end end 

now when trying run test @service not getting initialized object want to. seems method_1 not getting mocked behaviour defined. can how assign @service mocked object.

the problem you're having you're stubbing :method_1, allows control returns, while short-circuiting behaviour. unfortunately, method_1 returns irrelevant, it's does—assigning @service—that's interesting.

without seeing actual interface , design of class, can't suggest improvements on score, can @ least expectation work correctly substituting references instance variable (ie. @service.some_method) attr_reader:

class abc   attr_reader :service    # ...    def getsomething_1     return service.get_seomthing_1   end end 

and in spec:

describe abc   # ..    before     abc.any_instance(:service).and_return(myobject)     # ...   end    "checks correctness of getsomething_1 method of class abc"     @abc = abc.new("xyz")     @abc.getsomething_1.should eql("somevalue")   end end 

in case, instance of abc return mock when attribute service called, allowing getsomething_1 correctly reference mock.