Handlebars Templates in Unit Tests, How To - node.js

I'm creating client-side tests in YUI3, and need to compile the handlebars template for the page I'm testing.
We're running a Node app with hbs set as the rendering engine, so when requests come into the server the router responds by calling res.render() and making a call directly to the .hbs file in the views directory.
In the tests I need to instantiate handlebars template, then assign it to the DOM, but as the tests are javascript I don't have access to file stream functionality and handlebars.compile() doesn't take a path as an argument.
Basically I want to do something like this, but where the Handlebars.compile() method successively compiles the referenced template file:
var body = A.one(document.body);
var container = A.Node.create('<div id="test-container"></div>');
var domTemplate = Handlebars.compile('../../../../views/campaign/set-campaign-properties.hbs');
var dom = A.Node.create(domTemplate);
container.append(dom);
body.append(container);

Keep in mind that there is a big differance between the client and the server, you are asking to test client side items on the server which can cause some strange issues, but there are some good tools to help. Generally when I unit test my template rendering I will use something like phantomjs or selenium. You could however use jsdom or jest to handle parsing the dom on the server side.
I have worked up a sample with jsdom, http://runnable.com/me/VIZN1VmFRzsBJu8r
var Handlebars = require("handlebars")
var source = "<p>Hello, my name is {{name}}. I am from {{hometown}}. I have " +
"{{kids.length}} kids:</p>" +
"<ul>{{#kids}}<li>{{name}} is {{age}}</li>{{/kids}}</ul>";
var template = Handlebars.compile(source);
var data = { "name": "Alan", "hometown": "Somewhere, TX",
"kids": [{"name": "Jimmy", "age": "12"}, {"name": "Sally", "age": "4"}]};
var templateResult = template(data);
var jsdom = require("jsdom");
jsdom.env(
templateResult,
["http://code.jquery.com/jquery.js"],
function (errors, window) {
console.log("contents of p tag:", window.$("p").text());
}
);

Related

Server Side rendering in mongo with dust

Is it possible to fetch data from MongoDB and render a html template on the server side itself for a node-js project?
As of now in my serverside js file I've done the following.
//Failing array will be populated by a db.find later on.
var failing = [
{ name: "Pop" },
{ name: "BOB" }
];
/*Now i have to send a mail from the server for which I'm using nodemailer.
Where do i store the template ? This is what I've done in the same file */
var template = "<body>{#failing} <p>{.name}</p> {/failing}</body>"
// Add this as the body of the mail and send it.
I'm not sure how to render the data and how to get it displayed. I'm aware storing the template in the variable isn't right but I'm not sure what else to do.
If your template is that short, you can store it in a variable without problem. Obviously, you can store it in a file also.
Let's say you decide to store it in a file index.dust:
<body>{#failing} <p>{.name}</p> {/failing}</body>
Now, in your node controller you need to load the file and generate the html content from it:
const fs = require('fs');
const dust = require('dustjs-linkedin');
// Read the template
var src = fs.readFileSync('<rest_of_path>/index.dust', 'utf8');
// Compile and load it. Note that we give it the index name.
var compiled = dust.compile(src, 'index');
dust.loadSource(compiled);
// Render the template with the context. Take into account that this is
// an async function
dust.render('index', { failing: failing }, function(err, html) {
// In html you have the generated html.
console.log(html);
});
Check the documentation in order not to have to compile the template every time you have to use it.

Is there a way to render a NodeJs Express view to a variable?

Is there a way to render an express view to a variable as opposed to the response stream?
var view = path.join( __dirname, '/../customer-product/views/copysheet.html');
res.render( view, {
data: product
})
I need the html on the server side so that I can be passed to PhantomJs for PDF generation.
There's a pretty good article on it at Strongloop. The upshot is that you would interact directly with the view engine like so:
var templatePath = require.resolve('./copysheet.html');
var templateFn = require('jade').compileFile(templatePath); // or whatever view engine you're usingg
var output = templateFn({data:product});

Passing objects between nodejs and jade

I have the following code in my server.js
var cddata = [];
body.rows.forEach(function(doc) {
cddata.push([{id: doc.id, name: doc.key, text:doc.value.Time, group: 1}]);
});
response.render('timeline', {cddata: JSON.stringify(cddata)});
and I have the following in my Jade view file
script(src='vis/dist/vis.js')
link(rel="stylesheet", href="vis/dist/vis.css", type="text/css")
script.
//alert(cddata);
var options = {};
var data = new vis.DataSet(cddata);
var container = document.getElementById('visualization');
new vis.Timeline(container, data, options);
However, nothing related to the chart is rendered. I presume the object is not correctly passed to the jade file. Please help!
Also, is there a way to verify the incoming object in Jade? Alerts dont seem to work.
thanks
The <script> in your jade is a browser side script so won't be able to access variables in the templates generation scope. You'll need to output your data as JSON and read it in using browser side JavaScript, something like this:
script(src='vis/dist/vis.js')
link(rel="stylesheet", href="vis/dist/vis.css", type="text/css")
script.
var chartData = JSON.parse('#{cddata}')
var options = {};
var data = new vis.DataSet(chartData);
var container = document.getElementById('visualization');
new vis.Timeline(container, data, options);
After much deliberation, the following worked to pass object from node server to client side server scripting on Jade file.
on the server.js, where dbdata is an array of JSON objects
response.render('timeline', {dbdata:dbdata});
On the jade file,
script.
var chartData = !{JSON.stringify(dbdata)};
Thanks,

In Express.js, how can I render a Jade partial-view without a "response" object?

Using Express.js, I'd like to render a partial-view from a Jade template to a variable.
Usually, you render a partial-view directly to the response object:
response.partial('templatePath', {a:1, b:2, c:3})
However, since I'm inside a Socket.io server event, I don't have the "response" object.
Is there an elegant way to render a Jade partial-view to a variable without using the response object?
Here's the straight solution to this problem for express 3 users (which should be widely spread now):
res.partial() has been removed but you can always use app.render() using the callback function, if the response object is not part of the current context like in Liors case:
app.render('templatePath', {
a: 1,
b: 2,
c: 3
},function(err,html) {
console.log('html',html);
// your handling of the rendered html output goes here
});
Since app.render() is a function of the express app object it's naturally aware of the configured template engine and other settings. It behaves the same way as the specific res.render() on app.get() or other express request events.
See also:
http://expressjs.com/api.html#app.render for app.render()
https://github.com/visionmedia/express/wiki/Migrating-from-2.x-to-3.x for express 2.x > 3.x migration purposes
You can manually compile the Jade template.
var jade = require('jade');
var template = require('fs').readFileSync(pathToTemplate, 'utf8');
var jadeFn = jade.compile(template, { filename: pathToTemplate, pretty: true });
var renderedTemplate = jadeFn({data: 1, hello: 'world'});

How to Make a Call to Koa.js App Instance for Unit Tests

I don't know how I'd term this maybe 'static call to a koa router'? Does that seem like the right wordage here for what I'm really trying to accomplish if you were to talk about it technically?
Anyway, I'm using koa-router and I'm coding unit tests (not integration tests). So I do not want to invoke .listen() on my koa app because of that reason...it would create an http server which now makes my test an integration tests.
Instead in my test I simply want to make a straight call to the app object instance and call a route and be able to return no results and check that I returned no results in the response.
How can you do that? I can't find an example and I've tried all sorts of pseudo code attemps agains the koa app object.
If you want to test the function that koa-router routes to then just perform a unit test on that function and leave the routing out of it.
To me it sounds like you've got a file such as app.js and it contains all your code. What you can do is create a router.js file to put you route bindings and a services.js file where you can put your application logic.
So for example app.js might look like:
var koa = require("koa");
var app = module.exports = koa();
var router = require('./router.js');
app.use(router.unsecured.middleware());
app.listen(3000);
And router.js might look like:
var router = require("koa-router");
var service = require("./services.js");
var unsecured = module.exports.unsecured = new router();
unsecured.post('/account/signin', service.signinUser);
unsecured.post('/account/register', service.registerUser);
And services.js might look like:
module.exports.signinUser = function*(signinDetails) {
// contains your application signin logic
};
module.exports.registerUser = function*(registerDetails) {
// contains your application register logic
};
So in this manner you can individually test services.js. I don't see any value in individually testing router.js since it is so trivial. As #Dan Pantry shows you can test routing as part of an integration test using supertest.
Edit:
So this is a little experimental test I was playing around with to test that the routing is correct. I'm using mocha as the test runner and the code example I posted in my original code.
// standard library
var assert = require("assert");
// in app objects
var router = require('./router.js');
var service = require('./service.js');
describe("routing tests", function() {
it("test register routing, POST", function*(done) {
// arrange
var unsecured = router.unsecured;
var path = '/account/register';
var httpMethod = 'POST';
var expected = service.register.toString();
var actual;
// act
for (var i = 0; i < unsecured.stack.length; i++)
{
var pathMatch = unsecured.stack[i].path === path;
var methodMatch = unsecured.stack[i].methods.indexOf(httpMethod) >= 0;
if (pathMatch && methodMatch)
{
actual = unsecured.stack[i].middleware.toString();
break;
}
}
// assert
try {
assert.equal(expected, actual);
done();
} catch(err) {
done(err);
}
});
});
There is probably a neater way of doing this (and a more modular way for testing multiple paths) but as I said this is just a basic example to verify the routing is calling the correct service. What I'm doing is delving into the koa-router object to verify what path is bound to what service code depending on the HTTP method (e.g. POST, GET, etc).
If you have your routing and your services in modules this test completely avoids dealing with the main koa app. Although technically this test spans multiple units (the routing and the service code) so it would technically be an integration test but it does mean you don't go near app.listen() which is what you didn't want to call in your tests.

Resources