Allow method/property to return false

[stephanvierkant]

Q	A
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Tickets	fixes #3681
License	MIT
Doc PR	api-platform/docs#...

When using a method or property (like this example from the documentation) you can't return false right now.

Currently, this example:

<?php
// api/src/Entity/Book.php

namespace App\Entity;

use ApiPlatform\Core\Annotation\ApiResource;
use Doctrine\ORM\Mapping as ORM;
/**
 * @ApiResource(mercure="object.mercureOptions()")
 */
class Book
{
    /**
     * @ORM\Column(type="string")
     */
    private $foo;

    public function mercureOptions()
    {
        if ($this->foo !== 'bar') {
            return false;
        }

        return ['private' => false];
    }

will give an error message:

The value of the "mercure" attribute of the "Book" resource class must be a boolean, an array of options or an expression returning this array, "boolean" given.'

This 'must be boolean (..), "boolean" given' is very confusing.

With this PR, this example will work.

[dunglas]

Thanks @stephanvierkant

[stephanvierkant]

@dunglas Any idea when a new (2.5) release would be tagged/published?