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State of JavaScript 2025

Testing

Tools for testing your code

We're highlighting interesting features or libraries we think you should know about.

Library Highlight: bun test

After years of hoping for a more unified toolchain, it looks like JavaScript developers might finally be starting to get their wish.

Bun test is just one example of a test runner being baked into the runtime, with Node and Deno offering their own equivalents.

Useful Resources

Testing Tools Ratios Over Time

While Jest has long enjoyed a comfortable spot as the most-used testing tool, Vitest is climbing the ranks so fast that it wouldn't be surprising to see it overtake it in the upcoming year, especially with Jest's satisfaction ratio trending down.

Meanwhile, Storybook is an interesting case study in a project trying its best to address its users' frustrations. It's still showing a slight satisfaction loss compared to last year, but the rate of decline has slowed, and things might start looking up soon.

Jest
Mocha
Storybook
Cypress
Puppeteer
Testing Library
Playwright
WebdriverIO
Vitest
Selenium
TestCafe
Mock Service Worker
Node Test Runner
bun test

Mode:

View:

Usage:

Proportion of respondents having used an item
0%
20%
40%
60%
80%
100%
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
0%
20%
40%
60%
80%
100%

Other Testing Tools

While Deno's test runner wasn't included in the survey's main options, it did come first in freeform mentions.
0%
20%
40%
60%
80%
100%
1
Deno
+3
44
2
-1
36
3
-2
17
4
Japa
+3
17
5
10
6
Other Answers
93
0%
20%
40%
60%
80%
100%
% of question respondents
189
1%
10
We asked members of the JavaScript community to share their “pick of the year”

My 2025 Pick: SST

I didn't know about SST just a year ago, but I started using it for a new work project and it's been fanstastic! It really deserves more exposure.
We asked members of the JavaScript community to share their “pick of the year”

Michael Rambeau

Creator, BestOfJS

Number of Items

While other categories so far have hovered around 1-2 tools used, when it comes to testing respondents averaged a whopping 4.4, a sign that people may still be looking for that perfect test runner, and that things are far from settled in this area.
0%
4%
7%
11%
15%
19%
01
0
2,425
02
1
892
03
2
1,082
04
3
1,156
05
4
1,229
06
5
1,250
07
6
1,230
08
7
1,076
09
8
1,008
10
9
719
11
10
495
12
11
266
13
12
112
14
13
49
15
14
13
0%
4%
7%
11%
15%
19%
% of survey respondents
4.4

Testing Happiness

Happiness remains stable, with a slight uptick over the past three years.
1
2
3
4
5
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
1
2
3
4
5
Average {axis}
10,820
83%
3.5
3
10

Testing Pain Points

Mocking remains a major pain point for developers, with configuration and setup not far behind.
What pain points have you encountered when using testing tools?
(freeform question)
Multiple
0%
20%
40%
60%
80%
100%
01
Mocking
02
Configuration
03
Performance
04
Browser support
+13
05
-1
06
Excessive complexity
07
ESM & CJS
-2
08
browser_testing_issues
09
Flakiness
-2
10
E2E testing
-1
0%
20%
40%
60%
80%
100%
% of question respondents
1,405
11%
20
10

Recommended Resources

Testing Fundamentals
Steve Kinney
Temporal

Testing Fundamentals

Ship code with confidence! Learn the basics of testing and apply Test-Driven Development techniques to your workflow. Create automated tests for DOM elements and user interactions. Use mocks and spies to control your environment and test more complex code.
Enterprise UI Development: Testing & Code Quality
Steve Kinney
Temporal

Enterprise UI Development: Testing & Code Quality

Learn unit testing with Vitest, continuous integration via GitHub Actions, component and accessibility testing with Ax, mocking techniques, and code standard enforcement using ESLint and Husky & Lint-Staged.
Thanks to our partners for supporting us! Learn more.