When joining a new project without tests, here is the value you need to provide through the addition of tests:
- the application works and doesn’t crash
- the application works and supports a few input cases
- the application works and supports a variety of input cases
- the application works and is robust to most input cases
- Write a test that tests the common case usage of your function
- Write tests that cover edge cases of your function
- Write tests to cover all statements, branches, paths