Based on the 42Entwickler youtube Videos on unit testing here is a programming exercise for testdriven development.
In this repository you find a .net 5 solution with unit tests for a priority queue.
This tests allows you to implement a class named MyPriorityQueue in the PriorityQueueMA. Add the missing properties and methods so that the code compiles successfully.
Also add an enum type PersonTypes with the values Vip and Normal, so that the code compiles.
After that you should implement the Push- and Pop-Methods and the required properties. The tests will show you if your implementation is correct.
Implement the local state of the class with an array for the name and an array for the priority for each person. This internal state must be secret (=private).
We know that the internal state of a class mustn't be public to be able to control the access to the state and ensure a valid state if there are multiple variables depending on each other. But also a reason to have a secret state is that we can change or optimize the internal state of the class and everything still is working fine.
Create a private class PersonInfo containing the name and the PersonTypes-information. This private class is just a helper class for the representation of the internal state.
So in this step to show how cool a private internal state is: Remove the two arrays from Step 1 and just use one single array of type PersonInfo. But don't change any method signature.
That means all unit tests still work. Just the internal state is changed.