JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://raw.github.com/bestiejs/lodash/v0.9.0/lodash.min.js"></script>
<script src="http://backbonejs.org/backbone-min.js"></script>

JavaScript

var App = {};

App.OptionModel = Backbone.Model.extend({
    defaults: {
        'is_checked': false
    }
});

App.OptionCollection = Backbone.Collection.extend({
    model: App.OptionModel,
    getCheckedIds: function(){
        
        console.log(this.chain().where({'is_checked':true}));
        console.log(this.chain().where({'is_checked':true}).value());
        console.log(this.where({'is_checked':true}));

        // This works as expected
        //
        //return _.pluck(this.where({'is_checked':true}), 'id');
        

        // This does not work
        //
        //return this.chain().where({'is_checked':true}).pluck('id').value();
    }
});

var collection = new App.OptionCollection([
    {'is_checked': true}, {'is_checked': true}, {'is_checked': false}
]);


collection.getCheckedIds();