How to test AngularJS custom provider

Question

Does anyone have an example of how to unit test a provider?

For example:

config.js

an         


        

Answer 1

i've been using @Mark Gemmill's solution and it works well, but then stumbled across this slightly less verbose solution which removes the need for a fake module.

https://stackoverflow.com/a/15828369/1798234

So,

var provider;

beforeEach(module('app.config', function(theConfigProvider) {
    provider = theConfigProvider;
}))

it('tests the providers internal function', inject(function() {
    provider.mode('local')
    expect(provider.$get().mode).toBe('local');
}));

If your providers $get method has dependencies, you can either pass them in manually,

var provider;

beforeEach(module('app.config', function(theConfigProvider) {
    provider = theConfigProvider;
}))

it('tests the providers internal function', inject(function(dependency1, dependency2) {
    provider.mode('local')
    expect(provider.$get(dependency1, dependency2).mode).toBe('local');
}));

Or use the $injector to create a new instance,

var provider;

beforeEach(module('app.config', function(theConfigProvider) {
    provider = theConfigProvider;
}))

it('tests the providers internal function', inject(function($injector) {
    provider.mode('local')
    var service = $injector.invoke(provider);
    expect(service.mode).toBe('local');
}));

Both of the above would also allow you to reconfigure the provider for each individual it statement in a describe block. But if you only need to configure the provider once for multiple tests, you can do this,

var service;

beforeEach(module('app.config', function(theConfigProvider) {
    var provider = theConfigProvider;
    provider.mode('local');
}))

beforeEach(inject(function(theConfig){
    service = theConfig;
}));

it('tests the providers internal function', function() {
    expect(service.mode).toBe('local');
});

it('tests something else on service', function() {
    ...
});