decorators

Decorators

Testing recipes for decorators

Table of contents

• About decorators
• Boilerplate

About decorators

When is necessary modify behaviour in a specific angularjs component, such as directives, services and others, Decorators is a greatest idea to resolve this problem of a very elegant way. Decorators works intercepting the creation of a specific service, allowing it to override or modify the default behaviour of the service.

In this way, the object returned by the decorator may be the original service, or a new service object which replaces or wraps and delegates to the original service. And the better approach is that you can reuse and share these modifications in others apps easily.

Boilerplate

Before start we need to initialize the related decorator and mock it's dependencies.

describe('Decorator: $rootScope', function() {
  'use strict';

  var $rootScope;

  beforeEach(module('myApp'));

  beforeEach(inject(function(_$rootScope_) {
    $rootScope = _$rootScope_;
    $rootScope.showLogs = false;
  }));

  it('should log how many times the $apply method was called', function() {

    $rootScope.$apply();
    expect($rootScope.times).toBe(1);
    $rootScope.$apply();
    expect($rootScope.times).toBe(2);
    $rootScope.$apply();
    expect($rootScope.times).toBe(3);
  });
});