Answering normajeans' question about setting default value. Create a defaults object with same properties and merge with the arguments object
If using ES6:
function yourFunction(args){
let defaults = {opt1: true, opt2: 'something'};
let params = {...defaults, ...args}; // right-most object overwrites
console.log(params.opt1);
}
Older Browsers using Object.assign(target, source):
function yourFunction(args){
var defaults = {opt1: true, opt2: 'something'};
var params = Object.assign(defaults, args) // args overwrites as it is source
console.log(params.opt1);
}