[10.x] Allow testing prompts validation

[cerbero90]

When running tests, Laravel Prompts fall back to the console components.

The fallback takes care of running the console components repeatedly until their validation passes.

This is convenient when we want to interact with the user but it should not happen when our tests run as we may want to test the input validation in our console commands.

This PR lets us test the user input validation when we use Laravel Prompts in our console commands.

[taylorotwell]

I'll need @jessarcher to take a look.

[jessarcher]

Looks good to me, but I'm wondering whether it would be clearer (and avoid recursion) if we kept the loop and just break instead of continue when a validation error occurs while testing?

[jessarcher]

Actually, I'm wondering whether there will be any type issues with the returned value. Would it be better just to throw an exception when a validation error occurs during testing? In a real-world scenario, it shouldn't be possible for the code to continue until a valid value is passed, so I'd imagine we wouldn't want the code to continue when testing either.

[cerbero90]

thanks for your input @jessarcher, it really helped 👍

Looks good to me, but I'm wondering whether it would be clearer (and avoid recursion) if we kept the loop and just break instead of continue when a validation error occurs while testing?

by using break we would return null to the prompt which would cause a type error, unless we change the return types of the prompts to accept null values.

Actually, I'm wondering whether there will be any type issues with the returned value.

spot on, the previous implementation of this PR actually worked only for prompts that accept a string as a return type 👍

Would it be better just to throw an exception when a validation error occurs during testing?

this is probably the best solution, I updated the PR to throw a PromptValidationException (open to suggestions if you have better names in mind) that is caught by Illuminate\Testing\PendingCommand to avoid the bubble up, update the exit code and run the assertions as per normal.

[jessarcher]

Looks good, @cerbero90!