Hamcrest Matchers - Assert Type of List
assert, hamcrest, java, matcher
Solution
You can't. This is due to type erasure, you're not able to inspect the generic type. The compiler will enforce this for you. If you really want to test this, one option would be to grab the first element and make sure you can cast it to `SomePOJO`. (or alternatively grab every element and attempt the cast, but I believe this is overkill).
Problem
The Problem I'm currently trying to use Hamcrest Matchers to assert that the list type being returned is of a specific type. For example, let's say I have the following List that is being returned by my service call: ``` List<SomePOJO> myList; ``` I want to assert that the list being returned is parametrized of type `SomePOJO` and not `TheOtherPOJO`. However, it appears that Hamcrest Matchers does not have this sort of functionality. What I Have Tried After some research, I have seen the following options: - I have seen that there is `hasItem(isA(SomePJO.class))`, however this only works if there is an element in the list, and not if the list is empty. - I could use `is(instanceOf(List.class))`, however this will only assert that the item being returned is a List; it does not assert what type of list is being returned. - I can also add an element to the list immediately before the assert statement and then using `assertThat(somePojo.get(0), is(instanceOf(SomePOJO.class)))`, however this isn't very clean. It is also very similar to point #1. Conclusion / The Question Using Hamcrest Matchers, is there a way to assert that an empty list is parametrized of a certain type (such as `assertThat(myList, is(aListOf(SomePOJO.class)))`)?