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

Spek

https://www.spekframework.org/

Mocha

https://mochajs.org
Programming language

Kotlin

JavaScript

Category

Acceptance Testing, Unit Testing

Unit Testing, Intergration Testing, End-to-End Testing

General info

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.

Mocha is a widely used JavaScript test framework for Node.js

Mocha is a simple, flexible and the one of the widely adopted JS test framework. Mocha usually runs tests serially which enables the accurate reporting. Also it's useful for asynchronous testing, and provides various king of test reports. Spec is default test reporter for mocha, there are many test reports like Nyan, Dot matrix, Tap, Landing strip, List and Progress. Mocha is being used with many other test frameworks like Selenium WebDriver, Webdriver.io, wd and Cypress
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

No

Yes

It has an XUnit reporter available which outputs an XUnit-compatible XML document, often applicable in CI servers.
Client-side
Allows testing code execution on the client, such as a web browser

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.

Yes

Mocha Runs in the browser and is used widely to test front-end components and functionality. It can test various DOM elements, front-end functions and so on.
Server-side
Allows testing the bahovior of a server-side code

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

Yes

Mocha provides convenient ways of testing the Node server.It works well with Chai (an assertion library) where it provides the environment for writing server-side tests while we write the tests with Chai
Fixtures
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

Yes

Fixtures are available in spek through functions suchas beforeEachTest() and afterEachTest()

Mocha provides the hooks before(), after(), beforeEach(), and afterEach() to set up preconditions and clean up after your tests
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

spek has group fixtures available through the beforeGroup() and afterGroup() functions

N/A

Mocha allows grouping of 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

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

You can use the third party library mockito-kotlin

Provides Mocking capabilities through third party libraries like sinon.js, simple-mock and nock
Grouping
Allows organizing tests in groups

Yes

Tests are written using nested lambdas, each scope (level) can either be a group or a test

Yes

Grouping is supported and is accomplished by the using a nested 'describe()'
Other
Other useful information about the testing framework