https://github.com/squizlabs/PHP_CodeSniffer/wiki

Make sure you include the sniffer as require-dev dependency:

composer require --dev spryker/code-sniffer

The Development bundle provides a convenience command:

vendor/bin/console code:sniff

To automatically fix fixable errors, use

vendor/bin/console code:sniff -f

-v is useful for more info output. To run only a specific sniff, use the -s option.

You can also manually invoke the phpcs/phpcbf commands:

vendor/bin/phpcs --standard=vendor/spryker/code-sniffer/Spryker/ruleset.xml    

Add them to the corresponding category inside Sniffs folder and add tests in tests with the same folder structure.

To run all sniffs on themselves, use

vendor/bin/phpcs --standard=Spryker/ruleset.xml ./Spryker/Sniffs -v -s

Don't forget to test your changes:

php phpunit.phar

You can exchange or extend the Spryker coding standard by providing your own ruleset.xml. This can be configured in the Development bundle config:

// DevelopmentConfig.php

    /**
     * Either a relative or full path to the ruleset.xml or a name of an installed
     * standard (see `phpcs -i` for a list of available ones).
     *
     * @return string
     */
    public function getCodingStandard()
    {
        return '/path/to/your/ruleset.xml';
    }