//Stub var ioFile = { method1:function(){}, method2:function(){} }; //spyOn spyOn(ioFile, ‘method1’).and.throwError(“err”); spyOn(testModule, ‘testMethod’).and.callFake(function(param){ try{ ioFile.method1(); }catch(err){err} } var res = testModule.testMethod(); expect(res.message).toEqual(“err”);