Test Smell: it is a bad practice to mix test code with production code

[TestSmell]

Hi!

We notice that you mix the production code and the corresponding test code into the same file.
For example,

In fact, it is a bad practice for code organization.
The best practice is to separate test code and production code and use a parallel folder structure to place them, respectively.
So, we kindly suggest you re-organizing your code.