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

	WebdriverIO https://webdriver.io/	Concordion https://concordion.org/
Programming language	JavaScript	Java
Category	Browser Automation, Unit Testing, Functional 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	Concordion is a tool used to write and manage automated acceptance tests in Java based projects Concordion specifications are written in Markdown, HTML or Excel and then instrumented with special links, attributes or comments respectively. When the corresponding test fixture class is run, Concordion interprets the instrumentation to execute the test. Concordion lets you write them in normal language using paragraphs, tables and proper punctuation. This makes specification more natural to read and write, and helps everyone to understand and agree about what a feature is supposed to do.
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 You can specify tests for front-end components and functionality with concordion
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 server-side components and functionality with concordion.
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 Concordion contains fixtures which correspond to a specific instrumentation within the code. That is when specifications are written they are instrumented with special links, attributes or comments which are then run with their corresponding 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	Yes One can group fixtures in concordion
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	Apache License 2.0
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 By use of third party libraries like mockito
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 One can group tests into suites
Other Other useful information about the testing framework