Consider using assertThat(result).isEmpty(); from AssertJ for better readability and
consistency in assertions, assuming AssertJ is used elsewhere in the project.

src/test/java/io/spring/application/article/ArticleQueryServiceTest.java [191]

-assertFalse(result.isPresent());
+assertThat(result).isEmpty();
 

Add assertions to check the properties of user to ensure it is correctly initialized for
the test context.

src/test/java/io/spring/application/article/ArticleQueryServiceTest.java [187]

 User user = new User("test@test.com", "test", "123", "", "");
+assertNotNull(user.getEmail());
+assertNotNull(user.getUsername());
 

Rename the test method shouldReturnEmpstyOptionalWhenFindBySlugIsCalledWithNonExistingSlug
to correct the spelling mistake and improve readability, such as
shouldReturnEmptyOptionalWhenFindBySlugIsCalledWithNonExistingSlug.

src/test/java/io/spring/application/article/ArticleQueryServiceTest.java [186]

-public void shouldReturnEmpstyOptionalWhenFindBySlugIsCalledWithNonExistingSlug() {
+public void shouldReturnEmptyOptionalWhenFindBySlugIsCalledWithNonExistingSlug() {
 

Ensure that queryService is properly mocked or instantiated before use to avoid null
pointer exceptions during test execution.

src/test/java/io/spring/application/article/ArticleQueryServiceTest.java [189]

+// Ensure queryService is mocked or instantiated
 Optional<ArticleData> result = queryService.findBySlug("non-existing-slug", user);
 

Use descriptive variable names for user creation to enhance code readability and
maintainability.

src/test/java/io/spring/application/article/ArticleQueryServiceTest.java [187]

-User user = new User("test@test.com", "test", "123", "", "");
+User testUser = new User("test@test.com", "test", "123", "", "");