Testing tools
A testing tool can be a library or framework that helps you to write tests for your applications and evaluate the results. Under testing tools, you can find the following:
Testing libraries: This gives you a hook and functions to describe tests
Assertion libraries: This gives you functions to make expectations
Test runners: This discovers and runs your tests
Test coverage: This tells you which parts of your code are tested and which are not
Test reports: This makes reports in different formats such as HTML and JSON
Mocking, stubbing, faking tools: These give you ways to make fake objects with predictable behavior
Module mocking: This replaces a required module with a fake module and is useful to isolate modules
Stress tools: This makes many requests to the applications in order to see how it behaves in high demand circumstances
Browser testing: This emulates a user making inputs in the application as a whole
Explaining and showing how all these tools work is out of scope of...