Hey guys in this post, we will write JUnit test cases for Spring boot REST API. We will write test cases for database operations like Create, Read, Update and Delete.
Table of Contents
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Development process
Following are the development steps to create and test REST API using Spring boot
Create spring boot project
There are different ways to create a spring boot project, you can check the below articles to create one –
>> Create spring boot application using Spring initializer
>> Create spring boot application in Spring tool suite [STS]
>> Create spring boot application in IntelliJ IDEA
Add maven dependencies
Open pom.xml and add the following dependencies
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.4.3</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>in.bushansirgur</groupId>
<artifactId>productdata</artifactId>
<version>v1</version>
<name>productdata</name>
<description>Spring boot JPA</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>
</project>
When we create a spring boot project, by default it adds spring-boot-starter-test dependency to write JUnit test cases.
We have added Lombok dependency is a java library that reduces all the boilerplate code.
We have added spring-boot-starter-data-jpa to persist the data to the database.
Configure the data source
Open application.properties file and add the following content
spring.datasource.url=jdbc:mysql://localhost:3306/springdatajpa
spring.datasource.username=springbootapps
spring.datasource.password=springbootapps
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true
Create an entity
Create Product.java inside in.bushansirgur.springboot.entity package and add the following content
package in.bushansirgur.springboot.entity;
import javax.persistence.*;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;
@Setter
@Getter
@ToString
@Entity
@Table
public class Product {
@Id
private Long id;
private String name;
@Column(name="description")
private String desc;
private Double price;
}
Create a repository
Create ProductRepo.java inside in.bushansirgur.springboot.repo package and add the following content
package in.bushansirgur.springboot.repo;
import org.springframework.data.jpa.repository.JpaRepository;
import in.bushansirgur.springboot.entity.Product;
public interface ProductRepo extends JpaRepository<Product, Long> {
}
We have extended with CrudRepository interface which provides useful methods like save(), findById(), findAll() etc., to interact with the database.
Write Unit test cases
Inside src/test/java create ProductTest.java, where we will write unit test cases for the Product entity.
I use assertThat() method from AssertJ library for more readability than using JUnit’s assertion methods.
Test case for save operation
Let’s create a unit test case to save the product details to the database
@Test
public void testCreate () {
Product p = new Product();
p.setId(1L);
p.setName("iPhone XR");
p.setDesc("Fantastic");
p.setPrice(1000.00);
pRepo.save(p);
assertNotNull(pRepo.findById(1L).get());
}
Test case for read operation
Let’s create a unit test case to read all the products from the database
@Test
public void testReadAll () {
List list = pRepo.findAll();
assertThat(list).size().isGreaterThan(0);
}
Let’s create a unit test case to read a single product from the database
@Test
public void testRead () {
Product product = pRepo.findById(1L).get();
assertEquals("iPhone XR", product.getName());
}
Test case for update operation
Let’s create a unit test case to update the product details
@Test
public void testUpdate () {
Product p = pRepo.findById(1L).get();
p.setPrice(800.00);
pRepo.save(p);
assertNotEquals(700.00, pRepo.findById(1L).get().getPrice());
}
Test case for delete operation
Let’s create a unit test case to delete the product
@Test
public void testDelete () {
pRepo.deleteById(1L);
assertThat(pRepo.existsById(1L)).isFalse();
}
Test case for full CRUD operation
Let’s create a unit test case for complete CRUD operation
package in.bushansirgur.springboot;
import static org.assertj.core.api.Assertions.assertThat;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import java.util.List;
import org.junit.jupiter.api.MethodOrderer.OrderAnnotation;
import org.junit.jupiter.api.Order;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.TestMethodOrder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import in.bushansirgur.springboot.entity.Product;
import in.bushansirgur.springboot.repo.ProductRepo;
@SpringBootTest
@TestMethodOrder(OrderAnnotation.class)
class ProductdataApplicationTests {
@Autowired
ProductRepo pRepo;
@Test
@Order(1)
public void testCreate () {
Product p = new Product();
p.setId(1L);
p.setName("iPhone XR");
p.setDesc("Fantastic");
p.setPrice(1000.00);
pRepo.save(p);
assertNotNull(pRepo.findById(1L).get());
}
@Test
@Order(2)
public void testReadAll () {
List list = pRepo.findAll();
assertThat(list).size().isGreaterThan(0);
}
@Test
@Order(3)
public void testRead () {
Product product = pRepo.findById(1L).get();
assertEquals("iPhone XR", product.getName());
}
@Test
@Order(4)
public void testUpdate () {
Product p = pRepo.findById(1L).get();
p.setPrice(800.00);
pRepo.save(p);
assertNotEquals(700.00, pRepo.findById(1L).get().getPrice());
}
@Test
@Order(5)
public void testDelete () {
pRepo.deleteById(1L);
assertThat(pRepo.existsById(1L)).isFalse();
}
}
@Order and @TestMethodOrder annotation will specify the execution order because JUnit doesn’t run test methods in the order they appear in the code.
