This makes working with lists in tests much simpler. Able to create subclasses and understand how they inherit from each other. Extracting properties from items in the list and asserting on those Able to define a Kotlin class, create an object instance from it, and access its properties and methods.

Filtering lists and asserting on the filtered list.

ConclusionĪssertJ provides us full functionality on asserting lists. If we don’t provide it method will return Object.class type. We passed another argument to extractingResultOf() that represents the type that we expect back.

Now, we can filter on that one and assert that there is only one session that is shorter than two hours. After that, we get the list of outputs on that method, in our use case we get a list of durations of all sessions. Function of Kotlin List Interface abstract fun subList(fromIndex: Int, toIndex: Int): List, It returns a part of list between fromIndex (inclusive) to toIndex. This method has to be an inside class we are filtering on. Void filterOnAllSessionsThatAreFromToday_nestedFiltering () Īfter fetching all sessions, we call a method called getDurationInMinutes() using extractingResultOf().

Kotlin sublist