express-handlebars How to render JSON object return by helper function

var express = require('express');
var exphbs  = require('express3-handlebars');

var app = express();
var hbs = exphbs.create({
    // Specify helpers which are only registered on this instance.
    helpers: {
        foo: function () { return 'FOO!'; },
        bar: function () {
            var data = {
                user:[
                    {name: "foo"},
                {pass: "bar"}
                ]

            };
            return data;
        }
    }
});

there is a helper fun returns a JSON object.
I want to render it in a template, but I can not find any info from express-handlebars API.

<!-- Uses built-in `if` helper. -->
  {{#if showTitle}}
    <h1>Home</h1>
  {{/if}}

    <!-- Calls `foo` helper, overridden at render-level. -->
    <p>{{foo}}</p>

    <!-- Calls `bar` helper, defined at instance-level. -->
    {{#bar}}
    <p>user.name</p>
    <p>user.pass</p>
    {{/bar}}

This template can not show data correctly My question is how am I suppose to write the template or where can I find more info about express-handlebars?