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

Kotest

https://github.com/kotest/kotest

Behat

https://docs.behat.org/en/latest/
Programming language

Kotlin

PHP

Category

Unit Testing

Functional/Acceptance 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

Behat is an open source Behavior-Driven Development framework for PHP.

Behat uses the StoryBDD subtype of behaviour-driven development (the other subtype is SpecBDD); This means the tests we write with Behat look rather like stories than code. It is inspired by Ruby's Cucumber
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

No

No

Client-side
Allows testing code execution on the client, such as a web browser

Yes

You can test front-end components with kotest

Yes

To enable Behat to test a website, you need to add Mink and a browser emulator (selenium maybe, though slow) to the mix. Mink methods are the connector between Behat and an extensive list of available drivers, and they provide a consistent testing API.
Server-side
Allows testing the bahovior of a server-side code

Yes

Yes, you can test back-end components with kotest

Yes

Behat can be used for Data Integrity Testing to verify that database operations are functioning properly
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

One can use the 'Doctrinefixturesbundle' to create the required fixture loaders and load them in our Behat scenarios when required, using the 'BeforeScenario' hook.
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

Behat allows 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

By use of third party libraries like moodle-behat-generators
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

By using third party libraries like Mock and Prophecy
Grouping
Allows organizing tests in groups

Yes

You can create test suites with kotest

Yes

You can use tags to group features and scenarios together, independent of your file and directory structure
Other
Other useful information about the testing framework