Can Mockito stub a method without regard to the argument

Question

I m trying to test some legacy code  using Mockito   I want to stub a FooDao that is used in production as follows   foo   fooDao getBar new Bazoo       I can write   when fooDao getBar new Bazoo     thenReturn myFoo     But the obvious problem is that getBar   is never called with the same Bazoo object that I stubbed the method for   Curse that new operator    I would love it if I could stub the method in a way that it returns myFoo regardless of the argument  Failing that  I ll listen to other workaround suggestions  but I d really like to avoid changing the production code until there is reasonable test coverage

User · Answer

Use like this   when    fooDao getBar      Matchers  lt Bazoo gt any         thenReturn myFoo     Before you need to import Mockito Matchers

User · Answer

Another option is to rely on good old fashion equals method   As long as the argument in the when mock equals the argument in the code being tested  then Mockito will match the mock   Here is an example   public class MyPojo        public MyPojo  String someField             this someField   someField             private String someField        Override     public boolean equals  Object o             if   this    o   return true          if   o    null    getClass      o getClass     return false          MyPojo myPojo     MyPojo   o          return someField equals  myPojo someField               then  assuming you know what the value for someField will be  you can mock it like this   when fooDao getBar new MyPojo expectedSomeField    thenReturn myFoo     pros   This is more explicit then any matchers   As a reviewer of code  I keep an eye open for any in the code junior developers write  as it glances over their code s logic to generate the appropriate object being passed   con   Sometimes the field being passed to the object is a random ID   For this case you cannot easily construct the expected argument object in your mock code     Another possible approach is to use Mockito s Answer object that can be used with the when method   Answer lets you intercept the actual call and inspect the input argument and return a mock object   In the example below I am using any to catch any request to the method being mocked   But then in the Answer lambda  I can further inspect the Bazo argument    maybe to verify that a proper ID was passed to it   I prefer this over any by itself so that at least some inspection is done on the argument       Bar mockBar     generate mock Bar       when fooDao getBar any Bazo class        thenAnswer     InvocationOnMock invocationOnMock  - gt            Bazo actualBazo   invocationOnMock getArgument  0               inspect the actualBazo here and thrw exception if it does not meet your testing requirements          return mockBar             So to sum it all up  I like relying on equals  where the expected argument and actual argument should be equal to each other  and if equals is not possible  due to not being able to predict the actual argument s state   I ll resort to Answer to inspect the argument

User · Answer

http   site mockito org mockito docs 1 10 19 org mockito Matchers html  anyObject   should fit your needs   Also  you can always consider implementing hashCode   and equals   for the Bazoo class  This would make your code example work the way you want

User · Answer

when    fooDao getBar      any Bazoo class        thenReturn myFoo     or  to avoid nulls    when    fooDao getBar       Bazoo notNull         thenReturn myFoo     Don t forget to import matchers  many others are available    For Mockito 2 1 0 and newer    import static org mockito ArgumentMatchers      For older versions    import static org mockito Matchers

[java] Can Mockito stub a method without regard to the argument?

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