Sinon.js vs WebdriverIO comparison of testing frameworks
What are the differences between Sinon.js and WebdriverIO?

	Sinon.js https://sinonjs.org/	WebdriverIO https://webdriver.io/
Programming language	JavaScript	JavaScript
Category	Unit Testing	Browser Automation, Unit Testing, Functional Testing
General info	Standalone test stubs and mocks for JavaScript. Works with any unit testing framework. Sinon.js is a great library when you want to unit test your code with supports spies, stubs, and mocks. The library has cross browser support and also can run on the server using Node.js.	WebdriverIO is the next-gen WebDriver test framework for Node.js made upon Selenium WebdriverIO is written in JavaScript and uses Selenium under the hood. It also comes with its own inbuilt test runner and supports other testing frameworks like Jasmine, Cucumber, and Mocha
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	Yes Compatible	Yes
Client-side Allows testing code execution on the client, such as a web browser	Yes Sinon.js is a good library for unit testing your front-end code and has cross browser support	Yes WebdriverIO allows the use of advanced CSS selectors and makes it easy to find elements for front-end testing
Server-side Allows testing the bahovior of a server-side code	Yes Sinon.js can run on node.js to test back-end components and server-side behaviour	Yes It can be used to test server side 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	N/A	Yes WebdriverIO supports the creation of 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 WebdriverIO supports the creation of 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
Licence Licence type governing the use and redistribution of the software	New BSD License; Modified BSD 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)	Yes SinonJS is basically a library that we can use to create object mocks for unit testing	Yes It contains a mocking service called 'wdio-wiremock-service'
Grouping Allows organizing tests in groups		Yes WebdriverIO allows one to build test suites, you can run these test in parallel and organize them by adjusting the 'maxInstances' property in your config file
Other Other useful information about the testing framework