Unit Testing

Unit testing usually focuses on a single function or a small chunk of code.

Writing and fixing unit test code early can have the effect of managing bugs, errors and failing logic before they get out of hand.

Writing dedicated unit testing code is better than simply testing code interactively, which is a manual not repeatable process.

Test Driven Development (TDD) process likely will require developers to write the testing code first, expect it to fail, and then fixing the failing unit test before progressing.

Test automation is important because the number of unit tests can grow fast with new added features and functionalities.

It is different from regression testing and system integration testing, which both test the entire system more extensive including changed and unchanged parts.

It is also possible to be asked unit testing and testing questions in general in interviews.

Py test convention is to name the testing file similarly with the code file with a test suffix.