What are unit tests?

- [Voiceover] As a developer, I always try…to write readable, bug free code.…Most of the time, I have a good idea what…the code should do based on the application requirements.…I build my classes, add properties and methods,…and I attempt to write the code that I think meets…the requirements or use history.…At some point I need to test the code…to see if it meets my expectations.…Does it do what it's supposed to do?…Code also needs to go through integration tests…to make sure it performs well with…the other parts of the application.…

Then there is the suite of other tests that are performed…on code, performance testing, regression testing, UI tests,…and user acceptance tests.…But before the code is put through the testing gauntlet,…every developer does some form of code verification test.…The customary name for this type of code test is unit test.…Unit testing is done by programmers, for programmers.…It's something we do for our benefit.…And at its most basic, it helps verify…our code as working correctly.…Here's an example, this C Sharp library named brokerage lib…