To test a custom validation angularjs directive

This custom validation directive is an example presented at the official angular site. http://docs.angularjs.org/guide/forms It checks a text input is in number format or not.

var INTEGER_REGEXP = /^\-?\d*$/;
app.directive('integer', function() {
  return {
    require: 'ngModel',
    link: function(scope, elm, attrs, ctrl) {
      ctrl.$parsers.unshift(function(viewValue) {
        if (INTEGER_REGEXP.test(viewValue)) {
          // it is valid
          ctrl.$setValidity('integer', true);
          return viewValue;
        } else {
          // it is invalid, return undefined (no model update)
          ctrl.$setValidity('integer', false);
          return undefined;
        }
      });
    }
  };
});

To unit test this code, I wrote this:

describe('directives', function() {
  beforeEach(module('exampleDirective'));
  
  describe('integer', function() {
    it('should validate an integer', function() {
      inject(function($compile, $rootScope) {
        var element = angular.element(
          '<form name="form">' +
            '<input ng-model="someNum" name="someNum" integer>' +
          '</form>'
          );
        $compile(element)($rootScope);
        $rootScope.$digest();
        element.find('input').val(5);
        expect($rootScope.someNum).toEqual(5);
      });
    });
  });
});

Then I get this error:

Expected undefined to equal 5.
Error: Expected undefined to equal 5.

I put print statements everywhere to see what is going on, and it looks like the directive is never called. What is a proper way to test a simple directive like this?

The other answer's tests should be written as:

describe('directives', function() {
  var $scope, form;
  beforeEach(module('exampleDirective'));
  beforeEach(inject(function($compile, $rootScope) {
    $scope = $rootScope;
    var element = angular.element(
      '<form name="form">' +
      '<input ng-model="model.somenum" name="somenum" integer />' +
      '</form>'
    );
    $scope.model = { somenum: null }
    $compile(element)($scope);
    form = $scope.form;
  }));

  describe('integer', function() {
    it('should pass with integer', function() {
      form.somenum.$setViewValue('3');
      $scope.$digest();
      expect($scope.model.somenum).toEqual('3');
      expect(form.somenum.$valid).toBe(true);
    });
    it('should not pass with string', function() {
      form.somenum.$setViewValue('a');
      $scope.$digest();
      expect($scope.model.somenum).toBeUndefined();
      expect(form.somenum.$valid).toBe(false);
    });
  });
});

Note that $scope.$digest() now is invoked after $setViewValue. This sets the form into “dirty” state, otherwise it would remain “pristine”, which probably is not what you want.

I figured it out by reading angular-app code https://github.com/angular-app/angular-app This video also helps too http://youtu.be/ZhfUv0spHCY?t=31m17s

Two mistakes that I made:

• Do not bind directly to the scope when you are doing ng-model
• Use form controller to directly manipulate what to pass for directives

Here is the updated version. The directive is the same, only the test that I changed.

describe('directives', function() {
  var $scope, form;
  beforeEach(module('exampleDirective'));
  beforeEach(inject(function($compile, $rootScope) {
    $scope = $rootScope;
    var element = angular.element(
      '<form name="form">' +
        '<input ng-model="model.somenum" name="somenum" integer />' +
      '</form>'
    );
    $scope.model = { somenum: null }
    $compile(element)($scope);
    $scope.$digest();
    form = $scope.form;
  }));

  describe('integer', function() {
    it('should pass with integer', function() {
      form.somenum.$setViewValue('3');
      expect($scope.model.somenum).toEqual('3');
      expect(form.somenum.$valid).toBe(true);
    });
    it('should not pass with string', function() {
      form.somenum.$setViewValue('a');
      expect($scope.model.somenum).toBeUndefined();
      expect(form.somenum.$valid).toBe(false);
    });
  });
});

I test my custom directives searching in the object "$error" the name of the custom validation. Example:

  'use strict';

describe('Directive: validadorCorreo', function () {

  // load the directive's module
  beforeEach(module('sistemaRegistroProCivilApp'));

  var inputCorreo, formulario, elementoFormulario, scope, $compile;

  beforeEach(inject(function ($rootScope, _$compile_) {
    scope = $rootScope.$new();
    $compile = _$compile_;

    elementoFormulario = angular.element('<form name="formulario">' + 
      '<input type="text" name="correo" data-ng-model="correo" required data-validador-correo/>' + 
      '</form');
    scope.correo = '';
    elementoFormulario = $compile(elementoFormulario)(scope);
    scope.$digest();
    inputCorreo = elementoFormulario.find('input');
    formulario = scope.formulario;
    console.log(formulario.correo.$error);
  }));

  it('Deberia Validar si un correo ingresado en el input es correcto e incorrecto', inject(function ($compile) {
    
    inputCorreo.val('[email protected]').triggerHandler('input');
    expect(formulario.correo.$error.email).toBe(true); //Here, the name of the custom validation appears in the $error object.
    console.log(formulario.correo.$error);

    inputCorreo.val('[email protected]').triggerHandler('input');
    expect(formulario.correo.$error.email).toBeUndefined();//Here, the name of the custom validation disappears in the $error object. Is Undefined
    console.log(formulario.correo.$error.email)
  }));
});

I Hope i can help you!