Creating test cases

For unit and integration testing, we are using JUnit, which is a popular Java-based unit testing library. Spring Boot has built-in support for JUnit, making it easy to write tests for your Spring Boot application. The following source code shows an example skeleton of the Spring Boot test class. The @SpringBootTest annotation specifies that the class is a regular test class that runs Spring Boot-based tests. The @Test annotation before the method specifies to JUnit that the method can be run as a test case:

@SpringBootTest
public class MyTestsClass {
  @Test
  public void testMethod()  {
    // Test case code
  }
}

Assertions in unit testing are statements that can be used to verify whether the actual output of a code unit matches the expected output. In our case, the assertions are implemented using the AssertJ library that the spring-boot-starter-test artifact automatically includes. The AssertJ library provides assertThat() method that you can use to write assertions...