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


Programming language




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

Acceptance Testing, Unit Testing

General info

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,, wd and Cypress

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.
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.


It has an XUnit reporter available which outputs an XUnit-compatible XML document, often applicable in CI servers.


Allows testing code execution on the client, such as a web browser


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.


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.
Allows testing the bahovior of a server-side code


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


You can test back-end behaviour and componets by writing specifications to test back-end functionality and unit tests for individual back-end components
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

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


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.


Mocha allows grouping of fixtures


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


Licence type governing the use and redistribution of the software

MIT License

Modified BSD License

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)

Provides Mocking capabilities through third party libraries like sinon.js, simple-mock and nock


You can use the third party library mockito-kotlin
Allows organizing tests in groups


Grouping is supported and is accomplished by the using a nested 'describe()'


Tests are written using nested lambdas, each scope (level) can either be a group or a test
Other useful information about the testing framework