Differentiate between exception and error

[jwoertink]

Ref: luckyframework/lucky#1314
Ref: luckyframework/avram#773
Ref: luckyframework/lucky#1463

The idea here is that when you (the developer) are using Lucky, and you use the tools incorrectly, you should be given an error message. When you use the tools correctly, but it just doesn't work, then you should be given an exception.

I'm not totally sold on any single implementation for this, yet; however, my first thought is the distinction between these:

# Error
puts "You for got to add something".colorize.red
exit(1)

# Exception
raise "Unable to do that thing"

We sort of use a mix of these now, and it's pretty inconsistent.

If valid, print good, else print bad.
https://github.com/luckyframework/lucky/blob/a12ddfb1b9b0edfc6594e0555140f96987fd25ab/tasks/gen/action/action_generator.cr#L20-L25

do thing, rescue and print bad if it fails
https://github.com/luckyframework/lucky/blob/a12ddfb1b9b0edfc6594e0555140f96987fd25ab/tasks/gen/resource/browser.cr#L34-L40

if error print bad, else print good
https://github.com/luckyframework/lucky/blob/a12ddfb1b9b0edfc6594e0555140f96987fd25ab/tasks/gen/page.cr#L21-L26

run through the code and constantly check progress. raise exception at any point
https://github.com/luckyframework/lucky/blob/a12ddfb1b9b0edfc6594e0555140f96987fd25ab/tasks/gen/resource/browser.cr#L90-L101

[jwoertink]

This just came up again

Ref

Currently if you call a positional_arg, and the value is nil, you'll get this generic message like is required, but no value was passed. which is fine... not great, but ok... But in Lucky, we had some custom error message that would print out in a nice way. Then I converted a task from using ARGV.first to the positional_arg which turned the nice error in to an exception. In order to revert back to the nice error, I had to use some rescue magic. It would be better if we just created this separation between what's considered an exception and what's just a UI error.

lucky_task/src/lucky_task/task.cr

Line 137 in 8405c04

raise "{{ arg_name.id }} is required, but no value was passed."