Introduction
In this blog, we will discuss the REST Assured API testing tool, and we will also discuss the need and significance of REST Assured in API automation testing. Then, at last, we will learn the advantages and disadvantages of using REST Assured as a testing tool.
So before we learn about REST Assured, there are some terms that you must know as a prerequisite. Terms like API and REST API.
What are API and REST API?
An API stands for application programmable interface. It is a component that allows communication between the client and web servers and provides the information or data they need by following protocols.
A REST or RESTful API is one of the APIs. REST stands for Representational State Transfer which allows the communication or data sharing between two software applications with the help of HTTP protocol. REST APIs are based on HTTP methods.
What is REST Assured?
A REST Assured is an API testing tool that was developed by Johan Haleby. REST Assured is a Java package we can install in our java project, implement the API testing, validate the response we are getting, and make changes according to the response.
REST Assured is also an open-source program implemented in the Groovy programming language.
REST Assured is also an open-source program implemented in the Groovy programming language.
REST Assured supports all the HTTP methods like PUT, POST, GET, DELETE, and UPDATE.
You can also use the headers, cookies, and parameters to validate the response of the HTTP request.
Testing Mechanism
REST Assured follows the BDD style testing for the projects. BDD stands for Behaviour Driven Development, which includes test notations like Given, When, and Then; each notation has its functionality, making our code more human-readable.
given() - given keyword is like precondition notation like header and query parameter, which validates the request or filters the content from the API.
when() - when keyword tells which statement to execute.
then() - then keyword tells the response of the previous statement that was executed.
Example
given().queryParam("User_id","1234")
.when().get("API-URL-HERE").then().statusCode(200);
In the above example, we have used given() to filter the data by setting the query parameter with a user id. There is no when condition here. Then we use any URL, and if it responds with the data, then the status code will be 200, which means the API is working,
Versions of REST Assured
When you try to install the REST Assured package from the Maven CentraL Repo, you will see different versions of the REST Assured. You must keep in mind that you must install the io.rest-assured version of the REST Assured.
The package with group id com.jayway.restassured is the legacy version means it is version 2.2.0 or below. Please do not get confused between these versions and go for the first one if you are a beginner.
Need for REST Assured
Now, let's discuss the need for REST Assured or API testing.
On your smartphone, you must have weather applications that tell you about the current or upcoming weather conditions. Have you ever thought about how they can predict and display the response on your smartphone? How they calculate the weather conditions is a different topic.
Our main focus should be on how they can manage or display the data correctly. These applications use weather APIs to fetch and display the data on your smartphone. Since these APIs contain lots of data to filter and display on the application, the testers of these applications need to perform API testing to approve that the data they are fetching is valid and working.
Now let's talk about the need for REST Assured or its significance in the API testing community which there are many testing tools available.
➣ REST Assured can test complex applications with requests like GET, PUT, and many others.
➣ Implementing testing and validation of APIs is difficult in Java compared to dynamic languages like Groovy, Ruby, and REST Assured is implemented in Groovy.
➣ REST Assured focuses on the backend assurance means we do not need to worry about the interface.
➣ REST Assured also makes our code human-readable because of the BDD testing style,
➣ REST Assured supports data formats like XML and JSON , mainly used to transfer data.
➣ REST Assured is a Java DSL ( Domain Specific Language) means its main focus should be to validate the API testing based on the Java language.
Advantages of REST Assured
- It is an open-source tool; you do not need to worry about the licensing cost.
- It supports all the HTTP methods.
- It has a JSON schema validation library to validate the JSON schema.
- Parsing and validating XML and JSON can be done easily in REST Assured.
- You can integrate the REST Assured with other java libraries like TestNG and Junit as a test framework.
- It supports multiple authentication mechanisms available for APIs.
Disadvantages of REST Assured
- It does not support the testing of SOAP API, but it can be done with some changes.
- To use REST Assured, you need a strong foundation in Java.
Frequently Asked Questions
Is REST Assured a java library or framework?
REST Assured is a java based library to test the APIs.
Can we test the SOAP APIs in REST Assured?
We can, but REST Assured does not explicitly support SOAP APIs testing.
What makes the REST Assured code human-readable?
BDD style testing makes the REST Assured code human-readable.
Does REST Assured support only JSON data format?
REST Assured supports both XML and JSON data formats.
Do we need to buy the license for REST Assured?
REST Assured is an open-source API testing tool, so you do not need to worry about the license.
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