Fix misleading statement to boolean Command Options

[dsentker]

If an option is expected to be boolean (as shown in the documentation: --yell), seen here , the statement about InputOption::VALUE_OPTIONAL is misleading or wrong.

$input->getOption('yell') // always (!) returns NULL if no value is provided AND the third parameter from Command::addOption() is set to InputOption::VALUE_OPTIONAL

The documentation says about InputOption::VALUE_OPTIONAL :

"This option may or may not have a value (e.g., --yell or --yell=loud)"

Right here is the problem, because if the option has no value, it will always return NULL - no boolean operation is possible. I suggest a clarification about the correct operation to Boolean options.

[javiereguiluz]

I always have troubles understanding this. Maybe @chalasr can help us here or maybe we can think of some rewording that makes the examples easier to understand for all the possible use cases.

[OskarStark]

friendly ping @chalasr 😃

[chalasr]

Apologies for not replying earlier!
Actually I'm not sure to understand the issue.

Right here is the problem, because if the option has no value, it will always return NULL - no boolean operation is possible. I suggest a clarification about the correct operation to Boolean options.

If you define such an option with a non-null default value (e.g. false) and pass that option with no value when running the command (i.e. bin/console foo --yell), then getOption('yell') will return the default value (false).
And if you don't pass the option at all (i.e. bin/console foo), it will return null.
The current documentation looks good to me. Am I missing something?

[dsentker]

The current documentation is not wrong, but it is misleading. Imagine the following use case: A Boolean option to a command can be set from the console. This could be the desired command:

php bin/console app:test --foo // $input->getOption('foo') should be true
php bin/console app:test // foo is not used and $input->getOption('foo') should return false

Use this simple command setup for this:

class TestCommand extends Command
{
    protected static $defaultName = 'app:test';

    protected function configure()
    {
        $this->addOption('foo', null, InputOption::VALUE_OPTIONAL, 'Option description', false);
    }

    protected function execute(InputInterface $input, OutputInterface $output): int
    {
        $foo = $input->getOption('foo');
        $output->write(sprintf('foo is %s (%s)', var_export($foo, true), gettype($foo)));

        return 0;
    }
}

Note that the 5th parameter in at the $this->addOption line is set to false.

λ php bin/console app:test
foo is false (boolean)

This is the expected behaviour. But now the CLI user wants to set foo to true. It would be a great DX if the user can type

λ php bin/console app:test --foo

But this results in a NULL value for foo (It is neither true nor false (as defined by default).

In other words:

• The CLI user is not able to set foo to true (he can pass the string value "1" but this is not true) $this->getOption('foo') === true; // This comparison is never fulfilled: 'foo' is either a string, null or false, but never true
• There should be an input type that explicitly issues a Boolean value (such as InputOption::INPUT_BOOLEAN)
• The documentation should describe that a strict comparison (x === y) is not recommended, since the CLI option can not define an exact Boolean value.
• Alternatively, the documentation could describe the detour of using only $input->hasOption('foo') for an strict Boolean value comparison.

[carsonbot]

Thank you for this issue.
There has not been a lot of activity here for a while. Has this been resolved?

[carsonbot]

Hello? This issue is about to be closed if nobody replies.

[carsonbot]

Hey,

I didn't hear anything so I'm going to close it. Feel free to comment if this is still relevant, I can always reopen!