function populateAllPlugin(schema) {
    var paths = '';
    schema.eachPath(function process(pathname, schemaType) {
        if (pathname.match('_id')) return;
        if (schemaType.options.ref)
            paths += ' ' + pathname;
        if (schemaType.schema && schemaType.schema.paths)
            for (let key in schemaType.schema.paths)
                process(pathname + '.' + key, schemaType.schema.paths[key]);
    });

    schema.pre('find', handler);
    schema.pre('findOne', handler);

    function handler(next) {
        this.populate(paths);
        next();
    }
};



module.exports = populateAllPlugin;