Kotest vs AVA comparison of testing frameworks
What are the differences between Kotest and AVA?

Kotest

https://github.com/kotest/kotest

AVA

https://github.com/avajs/ava
Programming language

Kotlin

JavaScript

Category

Unit Testing

Unit Testing, Intergration Testing

General info

kotest is a powerful, elegant and flexible test framework for Kotlin, formerly known as kotlintest

Kotest has excellent support for data driven testing or table driven testing where it has the ability to quickly rerun the same test over and over with a predefined set of inputs and expected values

Futuristic, new, fast and concurrent JavaScript test runner with simple test syntax

AVA is a test runner for Node.js with a concise API, detailed error output. JS is a single-threaded but Node.JS is a parallel due to it's async behaviour. Ava leverages that and it can run tests concurrently
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

No

No

However Ava supports the TAP format which allows us to use the tap-xunit reporter to produce xUnit (JUnit) XML
Client-side
Allows testing code execution on the client, such as a web browser

Yes

You can test front-end components with kotest

Yes

You can write tests for the DOM with Ava, testing front-end components is easy with Ava
Server-side
Allows testing the bahovior of a server-side code

Yes

Yes, you can test back-end components with kotest

Yes

Ava utilizes the async I/O nature of Node and runs concurrent tests on NodeJs applications' back-endsA node server can have its endpoints tested with Ava
Fixtures
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

Yes

kotest contains fixtures, that is the setup / teardown functions

Yes

Using Ava's ava-fixture library it supports fixtures
Group fixtures
Allows defining a fixed, specific states of data for a group of tests (group-fixtures). This ensures specific environment for a given group of tests.

Yes

kotest has group fixtures available

Yes

Ava has support for group fixtures
Generators
Supports data generators for tests. Data generators generate input data for test. The test is then run for each input data produced in this way.

N/A

N/A

Licence
Licence type governing the use and redistribution of the software

Apache License 2.0

MIT License

Mocks
Mocks are objects that simulate the behavior of real objects. Using mocks allows testing some part of the code in isolation (with other parts mocked when needed)

Yes

You can use a third party library like mockk to create mocks

AVA has no mocking built in, to mock functions you can use third party libraries like Sinon.js.
Grouping
Allows organizing tests in groups

Yes

You can create test suites with kotest

No

There is no support for grouping tests
Other
Other useful information about the testing framework