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

	Behat https://docs.behat.org/en/latest/	Chai https://www.chaijs.com
Programming language	PHP	JavaScript
Category	Functional/Acceptance Testing	Unit Testing
General info	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	Chai is a BDD / TDD assertion library for Node.js and the browser that can be paired with any JavaScript testing framework. Chai is an assertion library, similar to Node's built-in assert and makes testing easier by giving you many assertions you can run against your code. It also includes a robust Plugin architecture for extending Chai's assertions and interfaces.
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	No	N/A
Client-side Allows testing code execution on the client, such as a web browser	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.	Yes Chai can be used in a browser environment to test front-end components and functionality
Server-side Allows testing the bahovior of a server-side code	Yes Behat can be used for Data Integrity Testing to verify that database operations are functioning properly	Yes Chai is used in a Node.JS environment to test server behaviour and functionality
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	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.	N/A
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 Behat allows for group fixtures	N/A
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.	By use of third party libraries like moodle-behat-generators	Yes By using chai-spec-generator plugin which will generate chai test specs from a JavaScript object
Licence Licence type governing the use and redistribution of the software	MIT License	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)	By using third party libraries like Mock and Prophecy	Yes By using by using a third party library like chai-jest-mocks which is a chai plugin that adds assertions for jest mock functions. You can also use sinon.js
Grouping Allows organizing tests in groups	Yes You can use tags to group features and scenarios together, independent of your file and directory structure	N/A
Other Other useful information about the testing framework