Chai vs unittest2 comparison of testing frameworks
What are the differences between Chai and unittest2?

	Chai https://www.chaijs.com	unittest2 https://pypi.org/project/unittest2/
Programming language	JavaScript	Python
Category	Unit Testing	Unit Testing
General info	Chai is a BDD / TDD assertion library for Node.js and the browser that can be paired with any JavaScript testing framework. Chai is an assertion library, similar to Node's built-in assert and makes testing easier by giving you many assertions you can run against your code. It also includes a robust Plugin architecture for extending Chai's assertions and interfaces.	Unittest2 is a newer version on the inbuilt unit testing framework unittest To use o use unittest2 instead of unittest, simply replace 'import unittest' with 'import unittest2'. It has many new features such as: - addCleanups for better resource management; -many new assert methods; - assertRaises as context manager, with access to the exception afterwards; - test discovery and new command line options (including failfast and better handling of ctrl-C during test runs); - class and module level fixtures: setUpClass, tearDownClass, setUpModule, tearDownModule; -test skipping and expected failures and many more improvements on the API and bug fixes
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	N/A	Yes unittest2 is a newer version of unittest which is an xUnit style framework for Python.
Client-side Allows testing code execution on the client, such as a web browser	Yes Chai can be used in a browser environment to test front-end components and functionality	Yes Front-end functionality and behaviour can be tested by unittest2. function by function
Server-side Allows testing the bahovior of a server-side code	Yes Chai is used in a Node.JS environment to test server behaviour and functionality	Yes We can write tests with unittest2 to test each function for server-side behaviour
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 By use of the 'setUp()' function which is called to prepare the test fixture
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 unittest2 allows you to group your initialization code buy use of the 'setUp()' function and clean up code with a 'tearDown()' function
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 By using chai-spec-generator plugin which will generate chai test specs from a JavaScript object	Yes unittest2 contains generator methods in the module 'unittest.TestCase'
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 using by using a third party library like chai-jest-mocks which is a chai plugin that adds assertions for jest mock functions. You can also use sinon.js	Yes Mocks are available from the library unittest.mock which allows you to replace parts of your system under test with mock objects
Grouping Allows organizing tests in groups	N/A	Yes One can build suites either manually or use test discovery to build the suite automatically by scanning a directory
Other Other useful information about the testing framework