I want to unit test "ProcessWindowFunction", but i cannot found usecase. when i try "WindowOperator", it must use ReducingStateDescriptor, this will lead to my windows only leave one event, but i want to see all event in "ProcessWindowFunction" logic. does anyone know how to test ProcessWindowFunction, then i can test windows with all event

Can’t you use a ListStateDescriptor? Something similar to https://stackoverflow.com/questions/63401125/flink-unit-test-over-processwindowfunctionin-out-key-w/71571080#71571080

i try it, but when i use "ListStateDescriptor" , the window iterable event type is arraylist, seems it take all event in window as single one.

Cool