AngularJS: Karma + Jasmine to test with _real_ backend - node.js

Going to run Karma+Jasmine to test angularjs client with real backend. Since Karma is using its own express but I need to access real nodejs backend with DB and other stuff, I'm thinking on adding interceptor into $httpProvider.interceptors that will just replace my calls to /api and redirec them into real backend location. Is there a better way?

You don't want to do that on unit tests (and personally I wouldn't even do that with E2E tests).
When doing unit tests, the $httpBackend get swapped with a dummy version that is not capable of doing real requests. That is intentional. You shouldn't do any test with the real backend.
On the other hand, there are E2E tests (where you test all your system together) where you could use the real backend in your tests (there are people who likes that, people who doesn't).
Keep in mind that unit test are all about units in isolation, that means that you don't care about dependencies and much much less about a backend.

Related

Use json-server to mock tests with Jest on Travis

My vuejs front-end makes API calls using Axios.
I'm making unit tests and integration tests with Jest. I use axios-mock-adapter to mock API, but I need to mock every endpoint.
To make it easier, I'd like to use json-server. On a development machine, there is no problem : I launch json-server, then I launch Jest tests.
My question is about Travis CI:
How do I launch json-server?
How can I be sure to have an available port
How/when do I stop json-server?

Performance difference between node-sass alone and Express middleware

Let's have NodeJS Express web app:
Is there any performance hit when using node-sass for compilation manually (by watcher in WebStorm for eyample) or by making Express middleware, so it's get compiled on http request?
The first example has a performance hit once while you're developing. The second example has the same performance hit every time an HTTP request occurs (or at least once if you use a CDN to cache assets). So, the 2nd is a bad idea IMO. Sass compilation should occur 1 time before deploying. You could even say the production environment need not even have these files.
I think you could actually use the node-sass-middleware, it will spare you the overhead setup of watching in development or the building process. Just run the middleware only in development environment, otherwise omit it.
if(process.env.NODE_ENV === "development"){
app.use(/** You Sass Middleware */)
}
Easy setup + No performance worries

Why don't there seem to be any robust HTTP server mocking packages for node? (or are there?)

I'm very new to Node.js, so I might just not be getting it, but after searching quite a bit, and trying a few different solutions, I am still not able to find a decent way to mock API responses using Node for acceptance testing.
I've got a javascript app (written in elm actually) that interacts with an API (pretty common, I imagine), and I want to write some acceptance tests... so I setup WebdriverIO with selenium and mocha, write some tests, and of course now I need to mock some API responses so that I can setup some theoretical scenarios to test under.
mock-api-server: Looked pretty nice, but there's no way to adjust the headers getting sent back from the server!
mock-http-server: Also looked pretty nice, lets me adjust headers, but there's no way to reset the mock responses without shutting down the whole server... !? And that has issues because the server won't shut down while the browser window is still open, so that means I have to close and relauch the browser just to clear the mocks!
json-server: Simple and decent way to mock some responses, but it relies entirely on files on disk for the responses. I want something I can configure from within a test run without reading and writing files to disk.
Am I missing something? Is this not how people do acceptance testing in the Node universe? Does everyone just use a fixed set of mock data for their entire test suite? That just sounds insane to me... Particularly since it seems like it wouldn't be that hard to write a good one based on express server that has all the necessary features... does it exist?
Necessary Features:
Server can be configured and launched from javascript
Responses(including headers) can be configured on the fly
Responses can also be reset easily on the fly, without shutting down the server.
I hit this problem too, so I built one: https://github.com/pimterry/mockttp
In terms of the things you're looking for, Mockttp:
Lets you start & reconfigure the server dynamically from JS during the test run, with no static files.
Lets you adjust headers
Lets you reset running servers (though I'd recommend shutting down & restarting anyway - with Mockttp that takes milliseconds, is clear & easily automatable, and gives you some nice guarantees)
On top of that, it:
Is configurable from both Node & browsers with identical code, so you can test universally
Can handle running tests in parallel for quicker testing
Can fake HTTPS servers, self-signing certificates automatically
Can mock as an intercepting proxy
Has a bunch of nice debugging support for when things go wrong (e.g. unmatched requests come back with a readable explanation of the current configuration, and example code that would make the request succeed)
Just to quickly comment on the other posts suggesting testing in-process: I really wouldn't. Partly because a whole bunch of limitations (you're tied to a specific environment, potentially even specific node version, you have to mock for the whole process, so no parallel tests, and you can't mock subprocesses), but mainly because it's not truly representative. For a very very small speed cost, you can test with real HTTP, and know that your requests & responses will definitely work in reality too.
Is this not how people do acceptance testing in the Node universe? Does everyone just use a fixed set of mock data for their entire test suite?
No. You don't have to make actual HTTP requests to test your apps.
All good test frameworks lets you fake HTTP by running the routes and handlers without making network requests. Also you can mock the functions that are making the actual HTTP requests to external APIs, which should be abstracted away in the first place, so no actual HTTP requests need to take place here as well.
And if that's not enough you can always write a trivially simple server using Express, Hapi, Restify, Loopback or some other frameworks, or plain http, or even net module (depending on how much control do you need - for example you should always test invalid responses that don't use HTTP protocol correctly, or broken connections, incomplete connections, slow connections etc. and for that you may need to use lower lever APIs in Node) to provide the mock data yourself.
By the way, you also always need to test responses with invalid JSON because people often wrongly assume that the JSON they get is always valid which it is not. See this answer to see why it is particularly important:
Calling a JSON API with Node.js
Particularly since it seems like it wouldn't be that hard to write a good one based on express server that has all the necessary features... does it exist?
Not everything that "wouldn't be that hard to write" necessarily has to exist. You may need to write it. Hey, you even have a road map ready:
Necessary Features:
Server can be configured and launched from javascript
Responses(including headers) can be configured on the fly
Responses can also be reset easily on the fly, without shutting down the server.
Now all you need is choose a name, create a repo on GitHub, create a project on npm and start coding.
You now, even "it wouldn't be that hard to write" it doesn't mean that it will write itself. Welcome to the open source world where instead of complaining that something doesn't exist people just write it.
You could try nock. https://github.com/node-nock
It supports all of your feature requests.

How to test Connect / Express middleware?

Supposed I have a middleware for Connect and / or Express. What's the best way to unit test this middleware?
Of course, I can set up an http server in the unit tests, and load the middleware into this. But supposed that I want to test startup behavior, I need several http servers, which soon gets complicated and unclear (think of using a new port in each single test).
Is there a better way, or is testing it inside a real server the best one can come up with?
supertest does the job, as pointed out by SLaks in the comments.

Load test a Backbone App

I've got an NGinx/Node/Express3/Socket.io/Redis/Backbone/Backbone.Marionette app that proxies requests to a PHP/MySQL REST API. I need to load test the entire stack as a whole.
My app takes advantage of static asset caching with NGinx, clustering with node/express and socket is multi-core enabled using Redis. All that's to say, I've gone through a lot of trouble to try and make sure it can stand up to the load.
I hit it with 50,000 users in 10 seconds using blitz.io and it didn't even blink... Which concerned me because I wanted to see it crash, or at least breath a little heavy; but 50k was the max you could throw at it with that tool, indicating to me that they expect you to not reasonably be able to, or need to, handle more than that... Which is when I realized it wasn't actually incurring the load I was expecting because the load is initiated after the page loads and the Backbone app starts up and kicks off the socket connection and requests the data from the correct REST API endpoint (from different server).
So, here's my question:
How can I load test the entire app as a whole? I need the load test to tax the server in the same way that the clients actually will, which means:
Request the single page Backbone app from my NGinx/Node/Express server
Kick off requests for the static assets from NGinx (simulating what the browser would do)
Kick off requests to the REST API (PHP/MySQL running on a different server)
Create the connection to the Socket.io service (running on NGinx/Node/Express, utilizing Redis to handle multi-core junk)
If the testing tool uses a browser-like environment to load the page up, parsing the JS and running it, everything will be copasetic (NGinx/Node/Express server will get hit and so will the PHP/MySQL server). Otherwise, the testing tool will need to simulate this by firing off at least a dozen different kinds of requests nearly simultaneously. Otherwise it's like stress testing a door by looking at it 10,000 times (that is to say, it's pointless).
I need to ensure my app can handle 1,000 users hitting it in under a minute all loading the same page.
You should learn to use Apache JMeter http://jmeter.apache.org/
You can perform stress tests with it,
see this tutorial https://www.youtube.com/watch?v=8NLeq-QxkSw
As you said, "I need the load test to tax the server in the same way that the clients actually will"
That means that the tests is agnostic to the technology you are using.
I highly recommend Jmeter, is widely used and you can integrate it with Jenkins and do a lot of cool stuff with it.

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