Mockingjay.js
When should you use Mockingjay
Did you ever created client centric apps like React or Angular apps, that depend on a complex set of REST-Services, that you can not simply mock by creating a database in the same format and fill it with testing data.
But you still want to have your test suite running properly with a fixed data set, so that you can rely on its results and write simple assertions.
Why no random fixtures?
Depending on how complex and entangled your REST data is, you might get a way with a combination of json-server and factory-girl
However, I was confronted with highly entangled data which was hard to autogenerate with factory-girl or other mock data generators. My Rest responses needed to share IDs accross several object literals and after I implemented it with a mock data generator, I figured it would be too hard to maintain it like that.
What is the basic idea?
So how can you generate highly complex but properly entangled mock data? You get it from real data of your servers. But setting up such complex system on each development machine can be a harsh pain in the ass. But you still need a source of mock data that you are controll of its changes and that are still available if your complex REST-System is down.
Mockingjay now gives you the opportunity to record the REST-calls and their results in a tiny express based node server as long as your production system is available by simply running your test suite. And use the prerecorded data when your production system might be offline or is changing its interface.
Setup
To install Mockingjay simply install it via npm:
npm install mockingjay.js --save-dev
Now you can start it by adding it as script to your package.json
... "scripts": { "mockingjay": "mockingjay", ... }
and start it by npm:
npm run mockingjay
By default mockingjay awaits a db.json-file and
runs on port 3000. But you can define this also
by its cli.
npm run mockingjay --db myDb.json --port 1234
Angular 1 Adapter
If you are working with Angular 1 you can simply use the provided $http-Interceptor that you can find in /lib/adapters/mockingjay-ng1-adapter.js
If you include this script into your build and
make it a dependency of your angular app:
angular.module('myApp', ['Mockingjay']) .constant('MockingjaySettings', { baseUrl: 'http://localhost', port: 3000, includingUrls: [ <regexes matching urls> ], excludingUrls: [ <regexes matching ulrs> ] })
Now all urls that match on of the regexes defined
in includingUrls will be redirected to mockingay.
All Urls matching also excludingUrls will not be
redirected to Mockingjay.
If an adapter for your favorite framework is still missing
You can simply redirect urls by yourself if your
favorite framework is not yet supported (looking forward
to your pull requests :).
You call your mockingjay instance with the (encodedURIComponent)[http://www.w3schools.com/jsref/jsref_encodeuricomponent.asp]
version of the url you want to be recorded by mockingjay:
http://localhost:3000/urls/http%3A%2F%2Fmy-rest-service
Record by testing
Now you can set Mocksettings set into recording
mode by putting {"dbIntegrityMode": "OVERWRITE"}
to
http://localhost:3000/dbIntegrityMode
and run a suite of tests that call your complex
REST-System and afterwards db.json will contain
all your mockdata. Mockingjay supports all sorts
of REST-verbs (GET, PUT, POST, DELETE)