Tutorials123

To test any API using Rest Assured, you need to follow these steps:

1. Setup

Before writing any Rest Assured test, we need to set up:

A Java project (Maven or Gradle is preferred).
Add the Rest Assured dependency in pom.xml or build.gradle.
Optionally add TestNG or JUnit as the testing framework.

2. Import Required Classes

In a Rest Assured test, you typically import:
Rest Assured methods for sending requests.
Assertions from TestNG/JUnit to validate the response.

3. Define the Base URI

You specify the API endpoint you want to test.
Example: If you are testing a sample API like https://reqres.in/api/users, this becomes your base URI.

4. Send a Request

You make a request to the API:

GET request to fetch data.
POST request to send data.
PUT/PATCH request to update data.
DELETE request to remove data.

The request can include headers, query parameters, or body depending on the API requirements.

5. Capture the Response

When the API responds, Rest Assured stores details such as:

Status code (200, 201, 400, 404, etc.)
Response body (JSON, XML, text, etc.)
Headers (content-type, server info, etc.)
Response time

6. Validate the Response

Assertions are applied to verify if the API behaves as expected. Typical checks are:

Status code is correct (e.g., 200 for success).
Response body contains expected values (e.g., user name, ID).
Headers are correct (e.g., content-type is application/json).
Response time is within acceptable limits.

7. Organize into a Test Case

The above steps (setup → request → response → validation) are wrapped inside a test method using TestNG or JUnit. This test can then be executed like any other automated test case.

Below we are automating GET API from reqres.in

Add Maven Dependencies

<dependencies>
    <dependency>
        <groupId>io.rest-assured</groupId>
        <artifactId>rest-assured</artifactId>
        <version>5.4.0</version>
        <scope>test</scope>
    </dependency>

<dependency>
    <groupId>org.testng</groupId>
    <artifactId>testng</artifactId>
    <version>7.9.0</version> <!-- Latest version -->
    <scope>test</scope>
  </dependency>
</dependencies>

Take a simple example of API:

https://reqres.in/api/users

Rest Assured Code:

To get Status code of given API:

	@Test
	public void test() {
		
		Response response = RestAssured.get("https://reqres.in/api/users?page=2");
		System.out.println(response.statusCode());
		
	}

To log all response on console:

	@Test
	public void test1() {
		RestAssured.baseURI = "https://reqres.in/api/";
		RestAssured.given().get("users?page=2").then().statusCode(200).log().all();
	}

Code Explanation:

Line	Purpose
baseURI	Sets the base URL.
given()	Prepares request specification.
when().get()	Triggers GET request.
then()	Begins response verification.
log().all()	Logs complete request/response.
statusCode(200)	Asserts HTTP status.

First Rest Assured Code to Test API