Refactoring startApp to add callback as a parameter and removing redundant varaibles

[moizjv]

-Refactoring startApp to add callback as a parameter and removing redundant varaibles.
-Related to #2026

[jlipps]

isn't this handled by the default case above?

[sebv]

Also you might want to clone before defaulting to avoid side effects.

startAppOptions = _.clone(startAppOptions);
_default(...

[moizjv]

@jlipps no defaults only handles undefined. Earlier code had a comment for null so thought to handle it explicitly.

[moizjv]

I have cloned startAppOptions but still have null check in place , @jlipps any ideas if we still need the null check, since defaults will only handle undefined, it was explicitly commented about the null check.

[sebv]

@moiz, write your own default helper.

function cloneAndDefault(opts, defaults) {
  opts = _(opts).clone();  
  _(opts).each(function(val, key) { opts[key] = opts[key] || defaults[key];});
  return opts;
}

[moizjv]

@sebv when values are set to false they would turn to true if default is true, so may be this looks better?

function cloneAndDefault(opts, defaults) {
  opts = _(opts).clone();  
  _(opts).each(function(val, key) { 
                  if(typeof opts[key] === "undefined" || opts[key] === null) {
                        opts[key]=defaults[key];}});
  return opts;
}

i was trying to tab in here so closed it by mistake :(

[sebv]

_.isUndefined(val) || _.isNull(val)

[moizjv]

I think _.each(defaults, function (val, key) { is correct

var cloneAndDefaults = function (opts, defaults) {
    opts = _.clone(opts);
    _.each(defaults, function (val, key) {
      if(_.isUndefined(opts[key]) || _.isNull(opts[key])){
        opts[key] = defaults[key];
      }
    });
    return opts;
  };

[moizjv]

updated as per suggestions :)

[jlipps]

This seems like a generally useful function. Maybe we should include it up top or in a helper file. If we're just doing it here there's no need to make it a general function; we could just operate directly on startAppOptions.