Composer/Migrations.php
private static function getDestinationDir(Composer $composer)
    {
        $extras = $composer->getPackage()->getExtra();
        
        return (array_key_exists('app-migrations-dir',$extras)) ?
            $extras['app-migrations-dir'] :
            getcwd().'/app/DoctrineMigrations';
    }
private static function getDestinationDir(Composer $composer)
    {
        $extras = $composer->getPackage()->getExtra();
        
        return (array_key_exists('app-migrations-dir',$extras)) ?
            $extras['app-migrations-dir'] :
            getcwd().'/app/DoctrineMigrations';
    }
Get the app migrations dir defined in root package, or
'app/DoctrineMigrations' instead.

@param Composer $composer
@return string