Backbone Collection Testing Gotcha

backbone_reset.js

/* Excerpt starting at line 785 */

// When you have more items than you want to add or remove individually,
// you can reset the entire set with a new list of models, without firing
// any granular `add` or `remove` events. Fires `reset` when finished.
// Useful for bulk operations and optimizations.
reset: function(models, options) {
  options || (options = {});
  for (var i = 0, length = this.models.length; i < length; i++) {
    this._removeReference(this.models[i], options);
  }
  options.previousModels = this.models;
  this._reset();
  models = this.add(models, _.extend({silent: true}, options));
  if (!options.silent) this.trigger('reset', this, options);
  return models;
},

backbone_set.js

/* Except starting at line 718 */

// If a duplicate is found, prevent it from being added and
// optionally merge it into the existing model.
if (existing = this.get(id)) {
  if (remove) modelMap[existing.cid] = true;
  if (merge) {
    attrs = attrs === model ? model.attributes : attrs;
    if (options.parse) attrs = existing.parse(attrs, options);
    existing.set(attrs, options);
    if (sortable && !sort && existing.hasChanged(sortAttr)) sort = true;
  }
  models[i] = existing;

collection_add_docs.txt

If you're adding models to the collection that are already in the collection, they'll be ignored, unless you pass {merge: true}, in which case their attributes will be merged into the corresponding models, firing any appropriate "change" events.

final_spec.js.coffee

providerArray = (new WellMatch.Models.Provider(display_name: 'a') for [1..18])
providers = new WellMatch.Collections.Providers(providerArray)

initial_result.js

Providers {fullParams: function, length: 1, models: Array[1], _byId: Object, _events: Object…}

initial_spec.js.coffee

provider = new WellMatch.Models.Provider({display_name: 'a'})
providerArray = (provider for [1..18])
providers = new WellMatch.Collections.Providers(providerArray)

intermediate_result.js

Providers {fullParams: function, length: 1, models: Array[18], _byId: Object, _events: Object…}

intermediate_spec.js.coffee

provider = new WellMatch.Models.Provider({display_name: 'a'})
providers = new WellMatch.Collections.Providers()
providers.models = providerArray