Springboot test fails to autowire TestRestTemplate when using junit5

Question

I am using springboot version 2.2.2.RELEASE.

I am trying to add tests with junit5, here is how I set it in my build.gradle:

testImplementation('org.springframework.boot:spring-boot-starter-test') {
    exclude group: 'junit', module: 'junit'
}
testImplementation "org.junit.jupiter:junit-jupiter-api:5.5.2"
testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:5.5.2"

And here is my test class:

//@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment= SpringBootTest.WebEnvironment.RANDOM_PORT, classes = UserServiceApplication.class)
@ActiveProfiles("it")
public class UserControllerIntegrationTest {
    @Autowired
    private TestRestTemplate testRestTemplate;

}

The problem is that restRestTemplate is null. The only way it works is when I use:

@RunWith(SpringRunner.class)

However, for my understanding this is for support of junit4, right?

I am using the not deprecated TestRestTemplate (org.springframework.boot.test.web.client.TestRestTemplate).

I also tried to add the following, but it didn't work too:

@ExtendWith(SpringExtension.class)

What am I missing?

Thank you.

Answer 1

Make sure your whole test is using JUnit 5 related annotations. Maybe your @Test annotation is still using JUnit 4.

The following example works for JUnit 5 and Spring Boot:

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.test.context.junit.jupiter.SpringExtension;

import static org.junit.jupiter.api.Assertions.assertNotNull;

@ExtendWith(SpringExtension.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT, classes = YourApplication.class)
public class TestOne {

  @Autowired
  private TestRestTemplate testRestTemplate;

  @Test
  public void test() {
    assertNotNull(testRestTemplate);
  }
}

Answer 2

Use below annotation to class level

pom dependency

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
        
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        
    </dependency> 

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

Test class

import static org.assertj.core.api.Assertions.assertThat;
import java.net.URI;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.boot.web.server.LocalServerPort;
import org.springframework.http.ResponseEntity;
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
class ApplicationTests{
        @LocalServerPort
        int randomServerPort;
     @Autowired
    private TestRestTemplate template;
    
    @Test
    public void contextLoads() {

    }
    @Test
    public void hello_ok() throws Exception {
        ResponseEntity<String> response = template.getForEntity(new URI("http://localhost:" + randomServerPort + "/"),
                String.class);
        
        assertThat(response.getBody()).isEqualTo("Greetings from Spring Boot!");
    }
}

Controller class

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {
    @GetMapping("/")
    public String index() {
        return "Greetings from Spring Boot!";
    }
}