BeforeAndAfter | Xamarin.Forms custom control showing a before-and-after view | Form library

As the name suggest BeforeAndAfter will run once(at start and at the end) for a test class. BeforeAndAfterEach will run before and after each test case in the class.

Use BeforeAndAfter: Suppose you want you create an in Memory database for the tests to run you will create it before running the test cases and then you will clear the memory after running all the test cases.

Use BeforeAndAfterEach: Suppose you have some cache value which requires different value for each test case to run, in that case you can change the value of that cache for before each test case and clear it after running a single test.

It's just because you are not assigning the result to any DF, and since you are always using the same variable (DF), you are always printing the original values.

You just need to change one line:

Declaring a class as Serializable doesn't mean that it can be serialized unless all of its field are Serializable as well.

Since your Test class extends Funsuite, it will have an "assertionsHelper" field which is not Serializable. So when you reference the "b1" field in your "forEach" method, Spark will try to serialize the Test instance along with all its field (including the assertionsHelper).

If you want to avoid this, you'll have to either define b1 somwhere else (in the test method scope or a companion object), or dereference b1 into a new variable before including it in the forEach function:

Regarding before and after particular test consider loan pattern

You call mainMenu under each function definition.