AngularJS Testing Strategies

AngularJS
testing
strategies
Nate Peterson
@njpetersonPa

Tests help us understand what
we’re doing and where we’re going

JavaScript is a dynamically typed
language with almost nohelp from
compiler

“One of the fundamental reasons
for choosing Angular is cited as that
it is built with testing in
mind.”

function MyController() {
var dep1 = new Dep1();
var dep2 = new Dep2();
//do something with dep1 and dep2
...
}

someModule.controller('MyController',
['$scope', 'dep1', 'dep2', function($scope, dep1, dep2) {
...
$scope.aMethod = function() {
...
}
...
}]);
The Angular way

function AddCtrl() {
var operand1 = $(#operand1);
var operand2 = $(#operand2);
var result = $(#result);
this.add = function() {
result = operand1 + operand2;
}
}

var operand1 = $('<input type="text" id="operand1" />');
var operand2 = $('<input type="text" id="operand1" />');
var result = $('<input type="text" id= "result" />');
var span = $('<span>');
$('body').html('<div class="ex1">')
.find('div')
.append(operand1)
.append(operand2)
.append(result);
var ac = new AddCtrl();
operand1.val('1');
operand2.val('1');
ac.add();
expect(result.val()).toEqual('2');
$('body').empty();

Controllers - The Angular way
function AddCtrl($scope) {
$scope.Calc = function() {
$scope.result = $scope.operand1 + $scope.operand2;
}
}

Controllers - The Angular way
var $scope = {};
var ctrl = $controller(‘AddCtrl’), {$scope: $scope };
$scope.operand1 = 1;
$scope.operand2 = 1;
$scope.calc();
expect($scope.result).toEqual(2);

Two types of testing
that
compliment each other

How much reality do you need
in your tests?

Knowing what to test is just as
important as how to test

Test all the
things
is not a strategy

“I get paid for code that works,
not for tests, so my philosophy is
to test as little as possible to reach
a given level of confidence…”
-- Kent Beck

Focus on behaviors
rather than implementation details

Example – Testing a simple controller

app.controller('AddCtrl', function($scope) {
$scope.calc = function() {
}
});

}
});
describe('adding 1 + 1', function() {
beforeEach(module('myApp'));
});

}
});
var ctrl, scope;
beforeEach(inject(function($controller, $rootScope) {
scope = $rootScope.$new();
ctrl = $controller('AddCtrl', { $scope: scope });
}));
});

}
});
var ctrl, scope;
beforeEach(inject(function($controller, $rootScope) {
ctrl = $controller('AddCtrl', { $scope: scope });
}));
it('should equal 2', function() {
scope.operand1 = 1;
scope.operand2 = 1;
scope.calc();
expect(scope.result).toEqual(2);
})
});

var app = angular.module('myApp', []);
app.controller('MoviesController', function($scope, $http) {
$http.get("/api/movies")
.then(function (result) {
$scope.movies = result.data;
});
});

describe("myApp", function () {
describe("MoviesController", function () {
var scope, httpBackend, http, controller;
});

beforeEach(inject(function ($rootScope, $controller,
$httpBackend, $http) {
httpBackend = $httpBackend;
http = $http;
controller = $controller;
}));
});

http = $http;
httpBackend.when("GET", "/api/movies")
.respond([{}, {}, {}]);
}));
});
});

http = $http;
.respond([{}, {}, {}]);
}));
it('should GET movies', function () {
httpBackend.expectGET('/api/movies');
controller('MoviesController', {
$scope: scope, $http: http
});
});
});
});

http = $http;
.respond([{}, {}, {}]);
}));
it('should GET movies', function () {
httpBackend.expectGET('/api/movies');
controller('MoviesController', {
$scope: scope, $http: http
});
httpBackend.flush();
});
});
});

angular.module('myApp', [])
.factory('greeter', function () {
return 'Hello';
})
.factory('worldGreeter', function (greeter) {
return greeter + ' World';
});

return 'Hello';
})
});
describe('worldGreeter', function () {
beforeEach(inject(function (_worldGreeter_) {
worldGreeter = _worldGreeter_;
}));
});

return 'Hello';
})
});
}));
it('should work with mocked greeter', function () {
expect(worldGreeter).toEqual('WAT World');
});
});

return 'Hello';
})
});
beforeEach(module('myApp', function($provide) {
$provide.value('greeter', 'WAT');
}));
}));
});
});

return 'Hello';
})
});
beforeEach(module('myApp', function ($provide) {
$provide.decorator('greeter', function ($delegate) {
return 'WAT';
});
}));
}));
});
});

Example – testing a directive

var app = angular.module('myApp', []);
app.directive('simpleDirective', function (){
return {
restrict: 'E',
template: '<div>{{value}}</div>',
scope: {
value: '='
}
};
});

describe('Testing simpleDirective', function() {
var scope, elem, directive, compiled, html;
beforeEach(function () {
module('myApp‘);
});
});
it('Should set the text of the element to whatever was passed.',
function() {
});
});

beforeEach(function (){
module('myApp');
html = '<simple-directive value="abc"></simple-directive>';
});
function() {
});
});

module('myApp');
html = ‘<simple-directive value="abc"></simple-directive>';
inject(function($compile, $rootScope) {
elem = angular.element(html);
compiled = $compile(elem);
compiled(scope);
});
});
function() {
});
});

    module('myApp');

       compiled(scope);
    });
});
   function() {
    expect(elem.text()).toBe('blah');
});
});

    module('myApp');

       compiled(scope);
    });
});
   function() {
     scope.abc = 'blah';
scope.$digest();
    expect(elem.text()).toBe('blah');
});
});

<body>
   <h1>Sample</h1>
   <div>
      Two Way Data Binding Sample
      <br/><br/>
      <input type="text" ng-model="name" />
      <span ng-show="name"><h4>Hello {{name}}</h4></span>
   </div>
</body>

describe(demo page', function() {
it('should greet the user', function() {
browser.get('[some route]');
});
});
<body>
   <h1>Sample</h1>
   <div>
      <br/><br/>
   </div>
</body>

element(by.model('name')).sendKeys('Nate Peterson');
});
});
<body>
   <h1>Sample</h1>
   <div>
      <br/><br/>
   </div>
</body>

var greeting = element(by.binding('name'));
});
});
<body>
   <h1>Sample</h1>
   <div>
      <br/><br/>
   </div>
</body>

var greeting = element(by.binding('name'));
expect(greeting.getText()).toEqual('Hello 'Nate
Peterson');
});
});
<body>
   <h1>Sample</h1>
   <div>
      <br/><br/>
   </div>
</body>

Use of a Mock API for e2e tests

Bloated controllers
that lead to
bloated specs

AngularJS Testing Strategies

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Editor's Notes