Wallaby.js vs Concordion comparison of testing frameworks
What are the differences between Wallaby.js and Concordion?

	Wallaby.js https://wallabyjs.com/	Concordion https://concordion.org/
Programming language	JavaScript	Java
Category	Unit Testing
General info	Wallaby.js is an integrated continuous testing tool for JavaScript. Wallaby.js runs your tests immediately as you change your code (you don’t even have to save the file) and reports code coverage and other results directly to your code editor. Its also uses various techniques such as dependency analysis to only execute tests affected by your code changes and parallel test execution to ensure your tests run as fast as possible.	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.	N/A	No
Client-side Allows testing code execution on the client, such as a web browser	Yes Wallaby.js can test front-end components and functionality	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 Wallaby.js can test server 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	N/A	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.	N/A	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	N/A	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)	By use of a third party library Jest works well with wallaby	Yes By use of third party libraries like mockito
Grouping Allows organizing tests in groups		Yes One can group tests into suites
Other Other useful information about the testing framework