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

	Chai https://www.chaijs.com	SpecFlow https://specflow.org/
Programming language	JavaScript	.NET
Category	Unit Testing	Acceptance Testing
General info	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.	SpecFlow is a test automation solution for .NET SpecFlow is a test automation solution for .NET which follows the BDD paradigm, and is part of the Cucumber family. SpecFlow tests are written with Gherkin, using the official Gherkin parser which allows you to write test cases using natural languages and supports over 70 languages.
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	N/A	No
Client-side Allows testing code execution on the client, such as a web browser	Yes Chai can be used in a browser environment to test front-end components and functionality	Yes Front-end behaviour is tested. With specflow specifications of the expected behaviours are made and specflow tests against this
Server-side Allows testing the bahovior of a server-side code	Yes Chai is used in a Node.JS environment to test server behaviour and functionality	Yes Back-end behaviour is tested. Specifications of the expected behaviours are made and specflow tests against them
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	N/A	Yes BeforeTestRun and AfterTestRun are executed once for each thread which is a limitation of the current architecture.
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.	N/A	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.	Yes By using chai-spec-generator plugin which will generate chai test specs from a JavaScript object	Yes SpecFlow contains a generator component. The SpecFlow IDE integration tries to locate the generator component in your project structure, in order to use the generator version matching the SpecFlow runtime in your project
Licence Licence type governing the use and redistribution of the software	MIT License	BSD 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 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	Yes Specflow intergrates well with mock to give it excellent mocking capabilities
Grouping Allows organizing tests in groups	N/A	Yes You can create test suites with specflow
Other Other useful information about the testing framework