Description

Enums represent a closed list of possible values. Supporting backed enums as option or argument type would enable:

• Auto-completion from enum cases values (ie: suggestedValues: BackedEnum::cases() values)
• Validation of the input value with a nice error message
• No need to call BackedEnum::tryFrom($input) in the command __invoke.

In Symfony itself, most of the --format options could be enums.

Example

Given a backed enum like this:

enum EmbeddingType: string
{
    case Image = 'image';
    case Description = 'description';
}

The argument parameter should accept a backed enum type,

#[AsCommand(name: 'app:regenerate')]
class RegenerateCommand
{
    public function __invoke(#[Argument] EmbeddingType $type): int
    {
        $this->generator->generate($type);
    }
}

If the command is run with an invalid value, an error is returned.

$ app/console app:regenerate yolo


                                       
  The "yolo" value is not accepted. Use one of "image", "description".