How can I do this using AssertJ (or Hamcrest)?

General Discussions
1

I want to unit test a method that returns a List<MyItem>, where MyItem has multiple properties, including name.

I only care that the list contains items with names "foo" and "bar", regardless of other properties. Ideally, I want a one-liner assertion.

I tried something like this in pseudo-code:

assert(listEntriesMatchInAnyOrder(myClass.getMyItems(), property("name"), new String[]{"foo", "bar"}));

How can I do this using AssertJ (or Hamcrest)? Specifically, is there a way to assert that the Iterable has elements with certain property values or use something like hasSize along with property checks in one line?

2

Using extracting with containsExactlyInAnyOrder

import static org.assertj.core.api.Assertions.assertThat;

List<MyItem> items = myClass.getMyItems();

assertThat(items)
    .extracting(MyItem::getName)             // extract the `name` property
    .containsExactlyInAnyOrder("foo", "bar"); // assert names match, any order

:white_check_mark: This ignores all other properties and checks only the name values.

3

Using extracting with contains

If you don’t care about exact size, just that “foo” and “bar” exist somewhere in the list:

assertThat(items)
    .extracting(MyItem::getName)
    .contains("foo", "bar");
4

If you want to assert that exactly these two items exist:

assertThat(items)
    .filteredOn(item -> Set.of("foo", "bar").contains(item.getName()))
    .hasSize(2);

This filters the list to only items with “foo” or “bar” and checks the count.