I'd create a require.js module and define it in the modules section of your plugin.jsonπ
define('myplugin/utils', [], function () { var Module = {}; Module.foo = function () { return 'bar'; } return Module; });Somewhere else...
require(['myplugin/utils'], function (utils) { console.log(utils.foo()); // 'bar' });and in plugin.json:
... "modules": { "myplugin/utils.js": "relative/path/to/your/utils.js" } ...