Creating tests for your domain objects

Earlier, we mentioned that testing is a multi-faceted approach. One of the most critical things in any system is its domain types. Testing them is vital. Essentially, anything publicly visible to users is a candidate for writing test cases.

So, let’s start by writing some test cases around the VideoEntity domain object we defined back in Chapter 3, Querying for Data with Spring Boot:

public class CoreDomainTest {
  @Test
  void newVideoEntityShouldHaveNullId() {
    VideoEntity entity = new VideoEntity("alice", 
      "title", "description");
    assertThat(entity.getId()).isNull();
    assertThat(entity.getUsername()).isEqualTo("alice");
    assertThat(entity.getName()).isEqualTo("title");
    assertThat(entity.getDescription())
 ...