Can you explain what the Rest Assured library is used for in API testing automation?

Rest Assured is a Java library that simplifies the automation of testing RESTful APIs. It provides a convenient DSL (Domain Specific Language) for writing API requests and verifying responses, making tests more readable and maintainable.

With Rest Assured, you can easily send HTTP requests (GET, POST, PUT, DELETE, etc.), set parameters, headers, request body, and also verify the response status, headers, and body content. This significantly simplifies the API testing process compared to using low-level HTTP clients.

Example of a simple test with Rest Assured:

import static io.restassured.RestAssured.*;
import static org.hamcrest.Matchers.*;

public class ApiTest {
    public void testGetUser() {
        given()
            .baseUri("https://api.example.com")
            .pathParam("id", 1)
        .when()
            .get("/users/{id}")
        .then()
            .statusCode(200)
            .body("username", equalTo("john_doe"));
    }
}