FirstSpringInitializrApplicationTests contains the basic context that can be used to start writing the tests as we start developing the application:

    package com.mastering.spring;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;

    @RunWith(SpringRunner.class)
    @SpringBootTest
    public class FirstSpringInitializrApplicationTests {

      @Test
      public void contextLoads() {
      }
   }

The test uses @SpringBootTest, which is used to launch unit tests with Spring Boot Framework. It contains one unit test to check whether the context launches properly.