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

pytest

https://docs.pytest.org/en/latest/

Mocha

https://mochajs.org
Programming language

Python

JavaScript

Category

Unit Testing

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

General info

Pytest is the TDD 'all in one' testing framework for Python

Pytest is a powerful Python testing framework that can test all and levels of software. It is considered by many to be the best testing framework in Python with many projects on the internet having switched to it from other frameworks, including Mozilla and Dropbox. This is due to its many powerful features such as ‘assert‘ rewriting, a third-party plugin model and a powerful yet simple fixture model.

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

pytest can test any part of the stack including 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

pytest is powerful enough to test database and server components and functionality

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

Pytest has a powerful yet simple fixture model that is unmatched in any other testing framework.

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

Pytest's powerful fixture model allows grouping of fixtures

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.

Yes

pytest has a hook function called pytest_generate_tests hook which is called when collecting a test function and one can use it to generate data

Licence
Licence type governing the use and redistribution of the software

MIT 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

By either using unittest.mock or using pytest-mock a thin wrapper that provides mock functionality for pytest

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

Yes

Tests can be grouped with pytest by use of markers which are applied to various tests and one can run tests with the marker applied

Yes

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