What are unit tests?
A unit test is a way of testing a unit - the smallest piece of code that can be logically isolated in a system.
Why is it important to write unit tests?
To have more control over an individual code block quality before integrating different components and then sent for regression testing.
What code should be tested with a unit test? What code is not suited well for unite test?
Units
What is Jest? What are some other popular JavaScript unit testing frameworks?
Testing framework