Feature request: Array property extending doesn't work when property has default value

[jrfnl]

PR #2154 added support for array properties being extended, however it appears that this doesn't work when an array property already has a default value set.

If we take the original example of the Generic.PHP.ForbiddenFunctions sniff, it all works correctly if you overrule the forbiddenFunctions property in a standard and then extend it from a project-based ruleset.

However, if you want to extend the default values of the forbiddenFunctions property:

public $forbiddenFunctions = [
     'sizeof' => 'count',
     'delete' => 'unset',
];

either via a standard or a project ruleset:

<rule ref="Generic.PHP.ForbiddenFunctions">
	<properties>
		<property name="forbiddenFunctions" type="array" extend="true">
			<element key="foo" value="fixedFoo"/>
			<element key="bar" value="fixedBar"/>
		</property>
	</properties>
</rule>

You end up with:

public $forbiddenFunctions = [
    'foo' => 'fixedFoo',
    'bar' => 'fixedBar',
];

instead of the expected:

public $forbiddenFunctions = [
    'sizeof' => 'count',
    'delete' => 'unset',
    'foo' => 'fixedFoo',
    'bar' => 'fixedBar',
];

@Majkl578 Any thoughts on this ?

Related #2153

[gsherwood]

This is an interesting use case, but not what the feature was designed to do, or how I documented it. I don't think this should be considered a bug - it just a feature that still doesn't exist despite the extends feature being added.

[jrfnl]

Let's call it a feature request in that case. Without having read the (not yet published as not yet released) changelog, intuitively I, at least, would expect this to work as described above.

[jrfnl]

Closing as replaced by PHPCSStandards/PHP_CodeSniffer#15