The testing space is a bit of an oddity: while the other parts of the JavaScript ecosystem have been slowly settling down around a few dominant solutions, testing is still very fragmented: lots of different, complementary tools share the pie. Even so, developers are satisfied by their testing solution overall, with the lowest satisfaction ratio being 68%.

The survey confirms that Mocha is still the most used unit testing framework with over 10k users. Being around for a long time, it has the largest ecosystem and most of the Node.js developers are familiar with it.

Jest follows closely in terms of usage but it has a slightly higher satisfaction rate: 96% versus 82%. As a side note, 96% is the second highest satisfaction in the whole survey this year. Only ES6 got a better mark!

This shows that developers really appreciate the efforts made by Facebook to provide a full-featured testing framework that can be used to test both front-end (it was intended to test React components, in the beginning) and back-end code, without requiring configuration.

In the "Single Page application" era, web applications are becoming more and more complex, with more and more logic implemented on the client side. The survey shows clearly that developers use many tools to test their applications.

The spectrum of testing is wide: unit tests, integration tests, end-to-end tests but also "visual testing", as we can see with the success of Storybook (the second highest satisfaction rate of the category).

The future of testing may include more solutions to make automated tests in the browser, a project like Cypress may be included in the next year survey and we may see more tools based on Puppeteer.