DisallowWritingIntoStaticProperties

info off by default

Group: Code style · PhpStorm name: DisallowWritingIntoStaticPropertiesInspection

Static properties are global mutable state. This opt-in rule flags assignments to static properties: by default only writes performed outside the class that declares the property; optionally every write.

Example

Default option (ALLOW_WRITE_FROM_SOURCE_CLASS = true):

<?php

namespace Shop;

use Shop\Cache as Store;

class Cache
{
    public static $hits = 0;
    public static $ttl;

    public function touch()
    {
        self::$hits += 1;
        static::$ttl = 30;
        Store::$ttl = 60;

        array_map(function ($v) {
            Cache::$hits = $v;
        }, []);
    }
}

class DiskCache extends Cache
{
    public static $ttl = 5;

    public function reset()
    {
        DiskCache::$ttl = 0;
        parent::$hits = 0;
        DiskCache::$hits = 0;
        Unknown::$whatever = 1;
        Cache::$hits++;
    }
}

function warmUp()
{
    Cache::$ttl = 10;
}

Nowhere::$thing .= 'x';
echo Cache::$hits;

Reported:

• line 19: Modify this static property only from the class that declares it.
• line 31: Modify this static property only from the class that declares it.
• line 32: Modify this static property only from the class that declares it.
• line 40: Modify this static property only from the class that declares it.
• line 43: Modify this static property only from the class that declares it.

Options

Option	Type	Default	Effect
ALLOW_WRITE_FROM_SOURCE_CLASS	bool	true	true: only writes from outside the declaring class are reported (D3). false: every static property assignment is reported (D2).

Configure

In custos.json:

{
  "rules": {
    "DisallowWritingIntoStaticProperties": {
      "enabled": true,
      "options": {
        "ALLOW_WRITE_FROM_SOURCE_CLASS": true
      }
    }
  }
}

Suppress

Before the statement or declaration (or the first statement of the file), either of:

// @custos-ignore DisallowWritingIntoStaticProperties

/**
 * @noinspection DisallowWritingIntoStaticPropertiesInspection
 */