Your testing strategy should be situational. Unit tests can efficiently handle, for example, libraries, error handling which cannot normally be reached, comple

Your testing strategy should be situational. Unit tests can efficiently handle, for example, libraries, error handling which cannot normally be reached, complex algorithms which are not AI based and require a large number of test cases, fragile pieces code and code patterns, and program design patterns which can be tested using inexpensive common tests. Consider the business value of quick tests in each of these situations. It is high. While your units have to come together in a way that allows your users to actually use your software, your business logic has to be represented in whole or in part by one or more unit. Testing this logic earlier on in the process and faster than other types of tests is better.