Your First REST Assured Test

How it works

REST Assured is a Java library for driving HTTP APIs from test code. There is no browser and no page to render: the library builds an HTTP request, sends it through Apache HttpClient, waits for the reply and wraps it in an io.restassured.response.Response. That object carries the three things every API check starts from: the status line, the response headers and the body.

The static field RestAssured.baseURI holds the scheme and host shared by every request, so a call only names the path that follows it. When it is never set, requests go to http://localhost on port 8080 (the constants DEFAULT_URI and DEFAULT_PORT), which is why a program that never sets it fails with java.net.ConnectException: Connection refused instead of reaching the practice API.

The status code is the server's one-number summary of what happened. getStatusCode() and its shorter twin statusCode() both return it as an int, while getStatusLine() gives the whole line, protocol and reason phrase included, such as HTTP/1.1 200 OK.

About the assignment

The starter already sets RestAssured.baseURI to the practice API, so your code only deals with paths. You send a single GET to the user collection and report which status code came back, the first fact any API test confirms.

What you will do

1. 1Call the static RestAssured.get() method with the /users path.
2. 2Keep what it returns in a variable of type Response, the import is already in the starter.
3. 3Ask that response for its status code with getStatusCode() or statusCode().
4. 4Print the number after the label Status Code: with one space between them.

Common mistakes

• Leaving the scheme off baseURI

  Writing the host without https:// does not quietly fall back to a default. As soon as the request is built, REST Assured throws IllegalStateException: Target host is null, because it cannot tell a host from a path without the scheme.

• Treating a 4xx or 5xx reply as an exception

  REST Assured hands back a 404 or 500 response like any other, no exception involved. If your code prints or uses the body without looking at the status, a broken endpoint looks like a success.

• Forgetting that baseURI is global

  RestAssured.baseURI is a static field, so every request in the same JVM shares it. One JUnit test that points it at another server silently changes the target of every test that runs after it.

In a real test suite

Related lessons

• Reading the Response BodyRequest a single user and read fields from its JSON body with jsonPath().
• Validate 200 OKTurn the printed status code into a real assertion with statusCode().
• Base URI SpecificationMove the base URI out of the static field and into a reusable request specification.

To try one of these calls on any API endpoint without a task, open the Online Selenium Java Compiler (REST Assured is included).

Starter code

The editor above opens with this code. Fill in the TODO lines, then run and submit it.

import io.restassured.RestAssured;
import io.restassured.response.Response;
import io.restassured.specification.RequestSpecification;

public class Main {
    public static void main(String[] args) {
        RestAssured.baseURI = "https://testkru.com/api";

        // TODO: Make a GET request to "/users" and store in a Response variable
        // TODO: Print the status code in format: "Status Code: <code>"
    }
}