Symfony version(s) affected

v2.1.0+

Description

In my use-case I have a node with enabled field, which can have 3 values:

• true: always enable component
• false: do not enable the component
• null: enable if it's needed (dependent on rather complex logic, outside of the scope of config schema)

The issue is I cannot use booleanNode() as it is well... boolean.

How to reproduce

    ->children()
        ->enumNode('enabled')
            ->values([true, false, null])
            ->defaultNull()
    ->end()

While the code above "works", using bin/console config:dump-reference reveals that in fact the null is not an expected values:

 doctrine_changeset_marshaller:
     enabled:              null # One of true; false

Possible Solution

The issue stems from usage of array_unique() in two places:

The issue is, \array_unique() compares values according to their string representation. I believe this is less than idea in the case of EnumNode. The \array_unique(), unlike functions like \in_array() does not support $strict parameter (and the discussion on that died in 2013). Thus, to really solve this issue a custom strict function would need to be used:

However, this does not cover empty string case. Given the EnumNode usage of the array where keys in the array aren't important, I think the solution would be to replace \array_unique() call with a function like:

function arrayUniqueStrict(array $values): array
{
    $unique = [];
    foreach($values as $k => $v) {
        if (!\in_array($v, $unique, true)) {
            $unique[$k] = $v;
        }
    }

    return $unique;
}

Additional Context

If the intention of EnumNode to be type-loose, then my suggested fix is obviously a no-go. In such a case I think it should be noted in the docs.