By removing a useless junk of code, I improved my code's quality

There were some variables that didn't have much
use. They were assigned and returned. Assuming
is not nice to have these kind of variables, I
removed them

In order to get my tests DRY, I created a file
where I could place describe scenarios I could
reproduce avoiding code repetition.

Moreover, there are some changes associated with
linting

Besides the tests, I managed to do it with less
repeated code, thanks to Jay (jmcdo29) that helped
me a lot showing his code.

After completing my issues, I'll probably try to
improve these tests

There was a wrong thing in the controller. In some methods,
if the answer was not a truthy value, we would have a thrown
exception. Point is that, it would never be falsey value, and
mocking it could result in false positive test returns. In
order to correct it, that check has been removed.

Besides, allRecipe was redundant. If it had an empty object
as a parameter, it would return allRecipes value, otherwise
it would return filterRecipes value. Problem is that filter
method already returns allRecipes if an empty object is
passed. This was corrected by removing the conditional, and
returning filterRecipes value

Inspired by Jay's code again, I've changed the deletion method.
It was not wrong before, but now it's a clearer code, and the
service became a little easier to test