Let’s Write First PATCH Request in REST Assured

Features of PATCH Request

• An HTTP patch request is carried out using the method of HTTP patch, which allows the data update of particular fields of an entity.
• A PATCH request is a set of instructions for modifying a resource.
• PATCH is not cacheable.
• We use the PUT request for complete updates and the PATCH request for partial updates.
• It remains in the browser history and can also be bookmarked.
• A server can declare that it supports PATCH by including it in the list in the response headers for Allow or Access-Control-Allow-Methods (for CORS). The PATCH request can execute one or multiple operations as a part of the JSON array.

Different Response Codes

A status code is a server's response to a browser. The browser generally sends a request to the server of the specified website when you enter a web address into the address bar. The server then returns the three-digit HTTP status code to the browser.

These were some of the most common HTTP errors. The proper knowledge of the status codes will help troubleshoot issues with your web servers or applications.

PATCH request in REST assured

Rest Assured uses the patch() method to send an HTTP PATCH request.

Before implementing the patch() method, we have to create a fake restful API using a JSON server. To install a JSON server, you need to follow the given steps. 

Step. 1

The first step is installing the JSON server using the npm command- 

Step. 2

After installing the JSON server, you need to create a db.json file using the following command-

In the above snapshot, we can see that the db.json file is created with some default data. On hitting the URL http://localhost:3000 you can view the default data in the file, which may look like this-

Step. 3

Now that the default file has been created, you can modify this file accordingly.  

Now on hitting the URL http://localhost:3000 we can see the modified data.

Step. 4

Now, we will require eclipse to create a PATCH request in REST Assured. For that, we will first set up the project following the given steps.

1. Click on this link and install eclipse. Select Eclipse IDE for Java Developers.  

1. Select the installation folder. Once it is installed, select your work directory.

1. Click on this link and generate a project like this-

1. Now extract the project file and import it into eclipse. For that-

Go to import->Maven->Existing Maven Project.

1. Now, a window will pop up where you have to give the root directory and click on finish. Hurray! The project is created, it will look like this-

Step. 5

To use REST assured in your project, you must include the dependencies listed below. Now go to the pom.xml file, edit as shown below, and save it.

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

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
           <dependency>
                 <groupId>io.rest-assured</groupId>
                 <artifactId>rest-assured</artifactId>
                 <version>4.1.2</version>
            </dependency>
    <dependency>
     <groupId>javax.xml.bind</groupId>
     <artifactId>jaxb-api</artifactId>
     <version>2.3.0</version>
  </dependency>
 </dependencies>

Alright! We are done with setting up the project. Now let us write the first PATCH Request in Rest Assured.

Step. 6

The next step is to create a class PatchMethod.java by right clicking on the package name com.codingNinjas.AnuradhaDixit.Student->New->Class.

Step. 7

Now that we have created the class, we need to import certain libraries to write the first PATCH request in REST assured. These libraries are-

import static io.restassured.RestAssured.*;
import io.restassured.http.ContentType;

Step. 8

Now we can proceed with the code implementation as shown in the given screenshot-

After writing this code right click on PatchMethod.java class -> Run as->Java Application.

Now you can view the output in console as shown below-

Step. 9

Now you can patch the data using the given code-

Here as you can see, we have changed the firstName. In a similar way, you can modify the data according to your requirement.  

Step. 10

After running the modified code, we can see the output in the console-

The same modifications will be reflected in the browser after refreshing the URL.

Frequently Asked Questions

What is RequestSpecBuilder?

RequestSpecBuilder is a class in Rest Assured. It contains methods that help in setting cookies, multipart details, header, body, authentication, query parameters, form parameters, path parameters, base URI, base path, proxy, etc.

What is REST API testing?

REST API Testing is an open-source technique for testing RESTful APIs in web applications. It is commonly used to test XML and JSON-based web applications. It works with all methods, including PUT, POST, PATCH, GET,  and DELETE. REST API is a Java library.

Why do we use REST assured?

It eliminates the need to write a large amount of source code to establish an HTTP connection, send a request, and receive and parse a response.

What makes a RESTful service?

RESTful web services support total client-server separation. They simplify and decouple various server components so that each part can evolve independently. Platform or technology changes at the server application do not affect the client application.

Why is REST API called REST?

A REST API also referred to as a RESTful API, is a representational state transfer API that complies with the constraints of the REST architectural style and enables communication with RESTful web services.  

Conclusion 

In this article, we have extensively discussed what REST assured is, different types of requests, and how to write a PATCH request in Rest assured. To learn more about Rest API, check the link below:

• What is Rest API
• How to Build a Rest API
• Building REST API with Bottle Framework

Refer to our guided paths on Coding Ninjas Studio to learn more about DSA, Competitive Programming, JavaScript, System Design, etc. Enroll in our courses and refer to the mock test and problems available. Take a look at the interview experiences and interview bundle for placement preparations.

Keep Coding!