WebdriverIO vs Spek comparison of testing frameworks
What are the differences between WebdriverIO and Spek?

	WebdriverIO https://webdriver.io/	Spek https://www.spekframework.org/
Programming language	JavaScript	Kotlin
Category	Browser Automation, Unit Testing, Functional Testing	Acceptance Testing, Unit Testing
General info	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	Spek is a specification framework for Kotlin Spek is a Kotlin-based Specification Testing framework for the JVM. It works as a JUnit 5 Test Engine meaning that we can easily plug it into any project that already uses JUnit 5 to run alongside any other tests that we might have.
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	Yes	No
Client-side Allows testing code execution on the client, such as a web browser	Yes WebdriverIO allows the use of advanced CSS selectors and makes it easy to find elements for front-end testing	Yes Yes you can test front-end behaviour by writing specifications to test front-end functionality. Developers can also write unit tests for individual front-end components.
Server-side Allows testing the bahovior of a server-side code	Yes It can be used to test server side behaviour and functionality	Yes You can test back-end behaviour and componets by writing specifications to test back-end functionality and unit tests for individual back-end components
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	Yes WebdriverIO supports the creation of fixtures	Yes Fixtures are available in spek through functions suchas beforeEachTest() and afterEachTest()
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	Yes spek has group fixtures available through the beforeGroup() and afterGroup() functions
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	MIT License	Modified 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 It contains a mocking service called 'wdio-wiremock-service'	Yes You can use the third party library mockito-kotlin
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	Yes Tests are written using nested lambdas, each scope (level) can either be a group or a test
Other Other useful information about the testing framework