[Proposal] duplicated array indexes rule

[wandersonwhcr]

Hello!

Yesterday I was developing my application and I had some problems with a git merge in an array definition. Example:

array configuration before git merge:

<?php
return array(
    // ...
    'default' => array(),
    // ...
);

array configuration after git merge --no-ff issue-1:

<?php
return array(
    'config' => array(
        'a' => true,
    ),
    // ...
    'default' => array(),
   // ...
);

array configuration after git merge --no-ff issue-2:

<?php
return array(
    'config' => array(
        'a' => true,
    ),
    // ...
    'default' => array(),
    // ...
    'config' => array(
        'b' => true,
    ),
);

Capturing configuration, PHP defined an array with this structure:

$config = array(
    'config' => array(
        'b' => true,
    ),
    'default' => array(),
);

Boom. Configuration for $config['config']['a'] was undefined. So, after 1 hour, I found the problem (hehe), duplication of indexes in array definition.

Can you create a rule for this problem, verifying duplicate indexes?

<?php
return array(
    'config' => array(
        'a' => true,
        'b' => true,
    ),
    // ...
    'default' => array(),
    // ...
);

PS: If we have duplicated subindexes, verify too?

PS2: I did the same question at php-cs-fixer project PHP-CS-Fixer/PHP-CS-Fixer#1469.

[ravage84]

Didn't you review the changes/merge?
Also a good IDE, such as PhpSotrm, warns you about this built-in.

Nontheless, if you would create a PR with a rule covering this issue, I would consider it merging it.

And, yes this rule should warn about any duplicated array keys in any sub-level.

[wandersonwhcr]

Yes, I did a review, but array had some 50+ indexes with 200+ lines and I'm human being 😄

Thank you!

[eeree]

@ravage84 @wandersonwhcr
It's already implemented in #484

[ravage84]

Oh thanks. Forgot to close.