Composer-managed coexisting CodeSniffer Rulesets for WordPress and Drupal

composer.json

{
    "minimum-stability": "dev",
    "require": {
        "drupal/coder": "^8.2",
        "squizlabs/php_codesniffer": "2.9.0",
        "wp-coding-standards/wpcs": "0.12.0"
    },
    "scripts"    : {
      "post-install-cmd": "\"vendor/bin/phpcs\" --config-set installed_paths ../../wp-coding-standards/wpcs,../../drupal/coder/coder_sniffer",
      "post-update-cmd" : "\"vendor/bin/phpcs\" --config-set installed_paths ../../wp-coding-standards/wpcs,../../drupal/coder/coder_sniffer"
    }
}