{"id":11057,"date":"2024-02-14T12:03:05","date_gmt":"2024-02-14T17:03:05","guid":{"rendered":"https:\/\/www.redline13.com\/blog\/?p=11057"},"modified":"2024-02-14T12:03:05","modified_gmt":"2024-02-14T17:03:05","slug":"functional-testing-with-k6","status":"publish","type":"post","link":"https:\/\/www.redline13.com\/blog\/2024\/02\/functional-testing-with-k6\/","title":{"rendered":"Functional Testing with k6"},"content":{"rendered":"

\"Functional<\/strong><\/p>\n

In previous posts we have covered the ability to use k6 for scalable load testing, however k6 is also a suitable framework for creating functional tests<\/a>. In this brief post, we will show you how to get started with using k6 as a functional testing tool.<\/p>\n

<\/a>Assertions in k6<\/h3>\n

There are two basic ways to write assertions in k6. One is using the built-in check<\/a> and group<\/a> functions. Perhaps a better alternative is to use the ChaiJS<\/a> extension (k6chaijs<\/a>), which is actually the favored approach in the official k6 documentation<\/a>. The latter allows use of the expect<\/code> function making functional tests more human-readable.<\/p>\n

<\/a>Creating a k6 Functional Test<\/h3>\n

We will need to import the k6chaijs<\/code><\/strong><\/a> extension to allow us to use the describe<\/code> and expect<\/code> methods. Add the following line to the top of your k6 test plan script:<\/p>\n

import chai, { describe, expect } from 'https:\/\/jslib.k6.io\/k6chaijs\/4.3.4.3\/index.js';<\/strong><\/pre>\n
Using the describe-expect<\/em> pattern, we can write functional statements such as the following:<\/p>\n
describe('Hello world!', () => {\n<\/strong>\u00a0 \u00a0 const response = http.get('https:\/\/test-api.k6.io\/');\n<\/strong>\u00a0 \u00a0 expect(response.status, 'response status').to.equal(200);\n<\/strong>});<\/strong><\/pre>\n
In this example, a successful response from a request to the k6 test-api<\/a> service is asserted. As long as the request out to this endpoint returns with a 200<\/code> success response, the test will continue to the next statement.<\/p>\n
<\/a>Advanced Functionality<\/h3>\n
The ChaiJS assertion library<\/a> extends a suite of getter functions that can be chained together in complex ways. The above example shows the simplest assertion which chains the to<\/code> and equal<\/code>\u00a0getters to create an equivalence test. Let\u2019s consider the following assertion:<\/p>\n
expect(response.json()).to.have.a.property('items');<\/strong><\/pre>\n
Here the response object from a request is analyzed as JSON<\/a>, and evaluated to contain an \u201citems\u201d property. Only if the response contains such a named property will the assertion succeed.<\/p>\n
A few selected additional chained getters for assertions:<\/p>\n