Can someone explain me why this is the right fix?

I mean, why shouldn't it return an array if the first argument is an array?

@mpdude https://github.com/aitboudad/symfony/blob/console_array_input/src/Symfony/Component/Console/Input/InputInterface.php#L24

@aitboudad Afaics, the first argument is not necessarily the command being executed. For example, the CommandTester just appends it to the existing input parameters when no command key is given.

So, if the filename argument were not defined as an array (or if another non-array argument were added in the future), getFirstArgument() would return that argument and not the command name.

@xabbuh yes I know :) in this PR I'm not attempts to return the command name as first argument but just to make ArrayInput compatible with InputInterface.

I agree with @mpdude, I don't think this is the right fix.

What about #14205?

Updated #14205.

what do you think to change getFirstArgument return type to mixed ?

    /**
     * @return mixed
     */
    public function getFirstArgument();

Is the first argument guaranteed to be the command name and thus a string?

If yes, where can I see that?

closing in favor of #14205