ng-describe/README.md

# ng-describe

> Convenient BDD specs for Angular

[![NPM][ng-describe-icon] ][ng-describe-url]
[![Quality][quality-badge] ][quality-url]

[![Build status][ng-describe-ci-image] ][ng-describe-ci-url]
[![manpm](https://img.shields.io/badge/manpm-%E2%9C%93-3399ff.svg)](https://github.com/bahmutov/manpm)
[![Codacy Badge][ng-describe-codacy-image] ][ng-describe-codacy-url]
[![semantic-release][semantic-image] ][semantic-url]

[![Coverage Status][ng-describe-coverage-image] ][ng-describe-coverage-url]
[![dependencies][ng-describe-dependencies-image] ][ng-describe-dependencies-url]
[![devdependencies][ng-describe-devdependencies-image] ][ng-describe-devdependencies-url]

Tested against angular v1.2, v1.3 and v1.4,
dependent projects tested using [dont-break][dont-break] - [![Circle CI] [circle-icon] ][circle-url].

Read [Unit testing AngularJS using ng-describe](http://glebbahmutov.com/blog/1-2-3-tested/) tutorial,
look through [Unit testing](http://slides.com/bahmutov/ng-describe) slides.

Join [Kensho](https://kensho.com/#/careers) and change the way financial industry analyzes information.
We love open source and use the bleeding edge technology stack.

[ng-describe-icon]: https://nodei.co/npm/ng-describe.png?downloads=true
[ng-describe-url]: https://npmjs.org/package/ng-describe
[ng-describe-ci-image]: https://travis-ci.org/kensho/ng-describe.png?branch=master
[ng-describe-ci-url]: https://travis-ci.org/kensho/ng-describe
[ng-describe-coverage-image]: https://coveralls.io/repos/kensho/ng-describe/badge.png
[ng-describe-coverage-url]: https://coveralls.io/r/kensho/ng-describe
[ng-describe-dependencies-image]: https://david-dm.org/kensho/ng-describe.png
[ng-describe-dependencies-url]: https://david-dm.org/kensho/ng-describe
[ng-describe-devdependencies-image]: https://david-dm.org/kensho/ng-describe/dev-status.png
[ng-describe-devdependencies-url]: https://david-dm.org/kensho/ng-describe#info=devDependencies
[ng-describe-codacy-image]: https://www.codacy.com/project/badge/25cb5d1410c7497cb057d887d1f3ea23
[ng-describe-codacy-url]: https://www.codacy.com/public/kensho/ng-describe.git
[semantic-image]: https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg
[semantic-url]: https://github.com/semantic-release/semantic-release

[quality-badge]: http://npm.packagequality.com/badge/ng-describe.png
[quality-url]: http://packagequality.com/#?package=ng-describe

[circle-icon]: https://circleci.com/gh/kensho/ng-describe.svg?style=svg
[circle-url]: https://circleci.com/gh/kensho/ng-describe
[dont-break]: https://github.com/bahmutov/dont-break



* [Intro](#intro)
* [Install](#install)
* [API](#api)
  * [Primary options](#primary-options)
  * [Secondary options](#secondary-options)
* [Examples](#examples)
  * [Test value provided by a module](#test-value-provided-by-a-module)
  * [Test a filter](#test-a-filter)
  * [Test a service](#test-a-service)
  * [Test controller and scope](#test-controller-and-scope)
  * [Test directive](#test-directive)
  * [Test controllerAs syntax](#test-controlleras-syntax)
  * [Test controller instance in custom directive](#test-controller-instance-in-custom-directive)
  * [Test 2 way binding](#test-2-way-binding)
  * [beforeEach and afterEach](#beforeeach-and-aftereach)
  * [Mocking](#mocking)
    * [Mock value provided by a module](#mock-value-provided-by-a-module)
    * [Angular services inside mocks](#angular-services-inside-mocks)
    * [Mock $http.get](#mock-httpget)
    * [Mock http responses](#mock-http-responses)
  * [Spying](#spying)
    * [Spy on injected methods](#spy-on-injected-methods)
    * [Spy on injected function](#spy-on-injected-function)
    * [Spy on 3rd party service injected some place else](#spy-on-3rd-party-service-injected-some-place-else)
    * [Spy on mocked service](#spy-on-mocked-service)
  * [Configure module](#configure-module)
  * [Helpful failure messages](#helpful-failure-messages)
* [Development](#development)
  * [Updating dependencies](#updating-dependencies)
* [Modules used](#modules-used)
* [License](#license)


## Intro

Unit testing and mocking AngularJs requires a lot of boilerplate code:
```js
describe('typical test', function () {
    var foo;
    beforeEach(function () {
        angular.mock.module('A');
        // other modules
    });
    beforeEach(inject(function (_foo_) {
        foo = _foo_;
    }));
    it('finally a test', function () {
        expect(foo).toEqual('bar');
    });
});
```

ng-describe makes testing simple modules a breeze.
Just list which modules you would like to load, which values / services / etc.
you would like to inject and then start testing. Same test as above using ng-describe
is much shorter and clearer:
```js
ngDescribe({
    modules: 'A',
    tests: function (foo) {
        it('finally a test', function () {
            expect(foo).toEqual('bar');
        });
    }
});
```
ng-describe can inject dependencies, mock modules, set configs, create controllers, scopes, and
even html fragments. For more details, continue reading. We also showed this library at AngularJS NYC
meetup, the slides are at [slides.com/bahmutov/ng-describe](http://slides.com/bahmutov/ng-describe).


## Install

`npm install ng-describe --save-dev`

Load ng-describe.js after angular and angular-mocks but before your specs, for example in Karma conf file.

```js 
// karma.conf.js
files: [
    'node_modules/angular/angular.js',
    'node_modules/angular-mocks/angular-mocks.js',
    'node_modules/ng-describe/dist/ng-describe.js',
    '<your source.js>',
    '<your specs.js>'
],
```

File `dist/ng-describe.js` includes es5-shim and other dependencies needed by 
the `ngDescribe` function.


## API

ng-describe provides a single function `ngDescribe` that takes an options object.

```js
ngDescribe({
  // your options
});
```

You do not have to specify every option, there are reasonable defaults. We also tried to make
the API [user-friendly](http://glebbahmutov.com/blog/user-friendly-api/).

`ngDescribe` returns itself, so you can chain multiple sets of specs easily

```js
ngDescribe({
  name: 'first suite'
  ...
})({
  name: 'second suite'
  ...
});
```

### Primary options

**name** - a string name for the spec, similar to BDD `describe(name, ...)`

**modules** - list of modules to inject

```js
angular.module('A', []);
angular.module('B', []);
ngDescribe({
  name: 'modules example',
  modules: ['A', 'B']
});
```

If you have a single module to inject, you can just use a string name without Array notation

```js
ngDescribe({
  name: 'single module',
  modules: 'A'
});
```

**inject** - list of dependencies to inject into unit tests. A single dependency can be just a string
without Array notation. All dependencies will be exposed as properties of the `deps` argument to the
tests callback

```js
angular.module('A', []).value('foo', 42);
ngDescribe({
  name: 'inject example',
  modules: 'A',
  inject: ['foo', '$timeout'],
  tests: function (deps) {
    it('has foo', function () {
      expect(deps.foo).toEqual(42);
    });
    it('has timeout service', function () {
      expect(typeof deps.$timeout).toEqual('function');
    });
  }
});
```

**tests** - callback function that contains actual specs. Think of this as equivalent to `describe` with
all necessary Angular dependencies taken care of.

```js
ngDescribe({
  inject: ['$q', '$rootScope'],
  tests: function (deps) {
    it('injects $q', function () {
      expect(typeof deps.$q).toEqual('function');
    });
    it('can be resolved', function () {
      deps.$q.when(42).then(function (value) {
        expect(value).toEqual(42);
      });
      // move promises along
      deps.$rootScope.$digest();
    });
  }
});
```

**Dependencies injection shortcut**

You can list the dependencies to be injected directly in the test callback.

```js
angular.module('shortcut', [])
  .constant('foo', 'bar');
ngDescribe({
  module: 'shortcut',
  tests: function (foo) {
    it('has constant', function () {
      console.assert(foo === 'bar');
    });
  }
});
```

You can inject multiple providers, including built-in services. If the test callback argument
is named `deps` or `dependencies` it will be assumed that you do NOT use the shortcut.

The shortcut was implemented using [changing named parameters trick][trick].

[trick]: http://glebbahmutov.com/blog/changing-the-function-arguments-trick/

**mocks** - top level mocks to be substituted into the tests.
The mocks override *any* injected dependencies among modules.

```js
ngDescribe({
  mocks: {
    // each module to mock by name
    moduleName1: {
      // each dependency from moduleName1 to mock
      dependencyName1: mockValue1,
      dependencyName2: mockValue2
      // the rest of moduleName1 is unchanged
    },
    moduleName2: {
      // dependencies to mock in moduleName2
    }
  }
});
```

For more information see examples below.

**controllers** - list of controllers by name that should be injected. Each controller
is created with a new `$rootScope` instance.

**NOTE: For each created controller, its SCOPE instance will be in the dependencies object.**

```js
angular.module('D', [])
  .controller('dController', function ($scope) {
    $scope.foo = 'foo';
  });
ngDescribe({
  modules: 'D',
  controllers: 'dController',
  tests: function (deps) {
    it('is a scope for controller', function () {
      expect(typeof deps.dController).toEqual('object');
      // deps.dController is the $scope object injected into dController
      expect(deps.dController.foo).toEqual('foo');
    });
  }
});
```

**element** - HTML fragment string for testing custom directives and DOM updates.

```js
ngDescribe({
  element: '<my-foo bar="baz"></my-foo>'
});
```

The compiled `angular.element` will be injected into the dependencies object under `element` property.
See examples below for more information. The compilation will create a new scope object too.

**parentScope** - when creating HTML fragment, copies properties from this object into the
scope. The returned dependencies object will have `deps.parentScope` that is the new scope.

```js
// myFoo directive uses isolate scope for example
ngDescribe({
  element: '<my-foo bar="baz"></my-foo>',
  parentScope: {
    baz: 42
  },
  tests: function (deps) {
    it('baz -> bar', function () {
      deps.parentScope.baz = 100;
      deps.$rootScope.$apply();
      expect(deps.element.isolateScope().bar).toEqual(100);
    });
  }
});
```

See "2 way binding" example below.

**configs** - object with modules that have provider that can be used to inject
run time settings.
See *Update 1* in
[Inject valid constants into Angular](http://glebbahmutov.com/blog/inject-valid-constants-into-angular/)
blog post and examples below.

### Secondary options

**verbose** - flag to print debug messages during execution

**only** - flag to run this set of tests and skip the rest. Equivalent to
[ddescribe or describe.only](http://glebbahmutov.com/blog/focus-on-karma-test/).

```js
ngDescribe({
  name: 'run this module only',
  only: true
});
```

**skip** - flag to skip this group of specs. Equivalent to `xdescribe` or `describe.skip`.
Could be a string message explaining the reason for skipping the spec.

**exposeApi** - expose low-level ngDescribe methods

The `tests` callback will get the second argument, which is an object with the following methods

    {
      setupElement: function (elementHtml),
      setupControllers: function (controllerNames)
    }

You can use `setupElement` to control when to create the element.
For example, instead of creating element right away, expose element factory so that you can create
an element *after* running a `beforeEach` block. Useful for setting up mock backend before creating
an element.

```js
ngDescribe({
  exposeApi: true,
  inject: '$httpBackend',
  // no element option
  tests: function (deps, describeApi) {
    beforeEach(function () {
      deps.$httpBackend
        .expectGET('/api/foo/bar').respond(500);
    });
    beforeEach(function () {
      // now create an element ourselves
      describeApi.setupElement('<study-flags />');
    });
    it('created an element', function () {
      la(check.has(deps.element));
    });
  });
});
```

See the spec in [test/expose-spec.js](test/expose-spec.js)

Or you can use `setupControllers` to create controller objects AFTER setting up your spies.

```js
angular.module('BroadcastController', [])
  .controller('broadcastController', function broadcastController($rootScope) {
    $rootScope.$broadcast('foo');
  });
```

We need to listen for the `foo` broadcast inside a unit test before creating the controller.
If we let `ngDescribe` create the "broadcastController" it will be too late. Instead we
can tell the `ngDescribe` to expose the low-level api and then we create the controllers when
we are ready

```js
ngDescribe({
  name: 'spy on controller init',
  modules: 'BroadcastController',
  inject: '$rootScope',
  exposeApi: true,
  tests: function (deps, describeApi) {
    it('can catch the broadcast in controller init', function (done) {
      var heardFoo;
      deps.$rootScope.$on('foo', function () {
        heardFoo = true;
        done();
      });
      describeApi.setupControllers('broadcastController');
    });
  }
});
```

See the spec in [test/controller-init-spec.js](test/controller-init-spec.js)

**http** - shortcut for specifying mock HTTP responses,
built on top of [$httpBackend](https://docs.angularjs.org/api/ngMock/service/$httpBackend).
Each GET request will be mapped to `$httpBackend.whenGET` for example. You can provide
data, response code + data pair, response code + data + headers and optionally statusText
or custom function to return something using custom logic.
If you use `http` property, then the injected dependencies will have `http` object that
you can flush (it is really `$httpBackend` object).

```js
ngDescribe({
  inject: '$http', // for making test calls
  http: {
    get: {
      '/my/url': 42, // status 200, data 42
      '/my/other/url': [202, 42], // status 202, data 42,
      '/my/smart/url': function (method, url, data, headers) {
        return [500, 'something is wrong'];
      } // status 500, data "something is wrong"
    },
    post: {
      '/my/url': '/my/url': [201, {message: 'ok'}, {Location: '/new/url'}, 'this is the new response'], // status data, headers and statusText
      // same format as GET
    }
  },
  tests: function (deps) {
    it('responds', function (done) {
      deps.$http.get('/my/other/url')
        .then(function (response) {
          // expect
          // response.status = 202
          // response.data = 42
          done();
        });
      deps.http.flush();
    });
  }
});
```
All standard methods should be supported (`get`, `head`, `post`, `put`, `delete`, `jsonp` and `patch`).

Each of the methods can return a function that returns an configuration object, see [mock http](#mock-http).

**step** - shortcut for running the digest cycle and mock http flush

```js
tests: function (deps) {
  it('runs the digest cycle', function (done) {
    $q.when(42).finally(done);
    deps.step();
    // same as deps.$rootScope.$digest();
  });
}
```

Also flushes the mock http backend

```js
http: {}
tests: function (deps) {
  it('returns expected result', function (done) {
    deps.$http.get(...)
      .then(...)
      .finally(done);
    deps.step();
    // same as deps.http.flush();
  });
}
```

**root** - alternative context for BDD callbacks

Imagine we are loading Angular and ngDescribe in a synthetic browser environment (like 
[jsdom](https://www.npmjs.com/package/jsdom)). ngDescribe attaches itself to synthetic `window`
object, but the test framework callbacks are attached to `global` object, not `window`.
By passing an alternative object, we allow ngDescribe to discover `it`, `beforeEach`, etc.

```js
// load ngDescribe in jsdom under Node
window.ngDescribe({
  root: global,
  tests: function (deps) {
    ...
  }
})
```

See repo [ng-describe-jsdom](https://gitlab.com/bahmutov/ng-describe-jsdom) for actual
example that tests Angular without a browser, only a synthetic emulation.


## Examples

Some examples use Jasmine matchers, others use `la` assertion from
[lazy-ass](https://github.com/bahmutov/lazy-ass) library and *done* callback argument
from [Mocha](http://visionmedia.github.io/mocha/) testing framework.

Also, note that the dependencies object is filled **only** inside the unit test callbacks `it` and
setup helpers `beforeEach` and `afterEach`

```js
ngDescribe({
  inject: 'foo',
  tests: function (deps) {
    // deps is an empty object here
    beforeEach(function () {
      // deps object has 'foo'
    });
    // deps is an empty object here
    it(function () {
      // deps object has 'foo'
    });
    // deps is an empty object here
    afterEach(function () {
      // deps object has 'foo'
    });
  }
});
```

### Test value provided by a module

```js
// A.js
angular.module('A', [])
  .value('foo', 'bar');
// A-spec.js
ngDescribe({
  name: 'test value',
  modules: 'A',
  inject: 'foo',
  tests: function (deps) {
    // deps object has every injected dependency as a property
    it('has correct value foo', function () {
      expect(deps.foo).toEqual('bar');
    });
  }
});
```

### Test a filter

We can easily test a built-in or custom filter function

```js
ngDescribe({
  name: 'built-in filter',
  inject: '$filter',
  tests: function (deps) {
    it('can convert to lowercase', function () {
      var lowercase = deps.$filter('lowercase');
      la(lowercase('Foo') === 'foo');
    });
  }
});
```

### Test a service

We can inject a service to test using the same approach. You can even use multiple specs inside `tests` callback.

```js
// B.js
angular.module('B', ['A'])
  .service('addFoo', function (foo) {
    return function (str) {
      return str + foo;
    };
  });
// B-spec.js
ngDescribe({
  name: 'service tests',
  modules: 'B',
  inject: 'addFoo',
  tests: function (deps) {
    it('is a function', function () {
      expect(typeof deps.addFoo).toEqual('function');
    });
    it('appends value of foo to any string', function () {
      var result = deps.addFoo('x');
      expect(result).toEqual('xbar');
    });
  }
});
```

### Test controller and scope

We can easily create instances of controller functions and scope objects.
In this example we also inject `$timeout` service to speed up delayed actions
(see [Testing Angular async stuff](http://glebbahmutov.com/blog/testing-angular-async-stuff/)).

```js
angular.module('S', [])
  .controller('sample', function ($timeout, $scope) {
    $scope.foo = 'foo';
    $scope.update = function () {
      $timeout(function () {
        $scope.foo = 'bar';
      }, 1000);
    };
  });
ngDescribe({
  name: 'timeout in controller',
  modules: 'S',
  // inject $timeout so we can flush the timeout queue
  inject: ['$timeout'],
  controllers: 'sample',
  tests: function (deps) {
    // deps.sample = $scope object injected into sample controller
    it('has initial values', function () {
      la(deps.sample.foo === 'foo');
    });
    it('updates after timeout', function () {
      deps.sample.update();
      deps.$timeout.flush();
      la(deps.sample.foo === 'bar');
    });
  }
});
```

### Test directive

```js
angular.module('MyFoo', [])
  .directive('myFoo', function () {
    return {
      restrict: 'E',
      replace: true,
      template: '<span>{{ bar }}</span>'
    };
  });
ngDescribe({
  name: 'MyFoo directive',
  modules: 'MyFoo',
  element: '<my-foo></my-foo>',
  tests: function (deps) {
    it('can update DOM using binding', function () {
      la(check.has(deps, 'element'), 'has compiled element');
      var scope = deps.element.scope();
      scope.bar = 'bar';
      scope.$apply();
      la(deps.element.html() === 'bar');
    });
  }
});
```

### Test controllerAs syntax

If you use `controllerAs` syntax without any components (see [Binding to ...][binding] post or
[Separate ...][separate]), then you can still test it quickly

```js
angular.module('H', [])
  .controller('hController', function () {
    // notice we attach properties to the instance, not to the $scope
    this.foo = 'foo';
  });
  ngDescribe({
    module: 'H',
    element: '<div ng-controller="hController as ctrl">{{ ctrl.foo }}</div>',
    tests: function (deps) {
      it('created controller correctly', function () {
        var compiledHtml = deps.element.html();
        // 'foo'
      });
      it('changes value', function () {
        var ctrl = deps.element.controller();
        // { foo: 'foo' }
        ctrl.foo = 'bar';
        deps.element.scope().$apply();
        var compiledHtml = deps.element.html();
        // 'bar'
      });
    }
  });
```

[binding]: http://blog.thoughtram.io/angularjs/2015/01/02/exploring-angular-1.3-bindToController.html
[separate]: http://glebbahmutov.com/blog/separate-model-from-view-in-angular/

### Test controller instance in custom directive

If you add methods to the controller inside custom directive, use `controllerAs` syntax to
expose the controller instance.

```js
angular.module('C', [])
  .directive('cDirective', function () {
    return {
      controllerAs: 'ctrl', // puts controller instance onto scope as ctrl
      controller: function ($scope) {
        $scope.foo = 'foo';
        this.foo = function getFoo() {
          return $scope.foo;
        };
      }
    };
  });
ngDescribe({
  name: 'controller for directive instance',
  modules: 'C',
  element: '<c-directive></c-directive>',
  tests: function (deps) {
    it('has controller', function () {
      var scope = deps.element.scope(); // grabs scope
      var controller = scope.ctrl; // grabs controller instance
      la(typeof controller.foo === 'function');
      la(controller.foo() === 'foo');
      scope.foo = 'bar';
      la(controller.foo() === 'bar');
    });
  }
});
```

### Test 2 way binding

If a directive implements isolate scope, we can configure parent scope separately.

```js
angular.module('IsolateFoo', [])
  .directive('aFoo', function () {
    return {
      restrict: 'E',
      replace: true,
      scope: {
        bar: '='
      },
      template: '<span>{{ bar }}</span>'
    };
  });
```

We can use `element` together with `parentScope` property to set initial values.

```js
ngDescribe({
  modules: 'IsolateFoo',
  element: '<a-foo bar="x"></a-foo>',
  parentScope: {
    x: 'initial'
  },
  tests: function (deps) {
    it('has correct initial value', function () {
      var scope = deps.element.isolateScope();
      expect(scope.bar).toEqual('initial');
    });
  }
});
```

We can change parent's values to observe propagation into the directive

```js
// same setup
it('updates isolate scope', function () {
  deps.parentScope.x = 42;
  deps.$rootScope.$apply();
  var scope = deps.element.isolateScope();
  expect(scope.bar).toEqual(42);
});
```

### beforeEach and afterEach

You can use multiple `beforeEach` and `afterEach` inside `tests` function.

```js
ngDescribe({
  name: 'before and after example',
  modules: ['A'],
  inject: ['foo'],
  tests: function (deps) {
    var localFoo;
    beforeEach(function () {
      // dependencies are already injected
      la(deps.foo === 'bar');
      localFoo = deps.foo;
    });
    it('has correct value foo', function () {
      la(localFoo === 'bar');
    });
    afterEach(function () {
      la(localFoo === 'bar');
      // dependencies are still available
      la(deps.foo === 'bar');
    });
  }
});
```

This could be useful for setting up additional mocks, like `$httpBackend`.

```js
angular.module('apiCaller', [])
  .service('getIt', function ($http) {
    return function () {
      return $http.get('/my/url');
    };
  });
ngDescribe({
  name: 'http mock backend example',
  modules: ['apiCaller'],
  inject: ['getIt', '$httpBackend'],
  tests: function (deps) {
    beforeEach(function () {
      deps.$httpBackend.expectGET('/my/url').respond(200, 42);
    });
    it('returns result from server', function (done) {
      deps.getIt().then(function (response) {
        la(response && response.status === 200);
        la(response.data === 42);
        done();
      });
      deps.$httpBackend.flush();
    });
    afterEach(function () {
      deps.$httpBackend.verifyNoOutstandingRequest();
      deps.$httpBackend.verifyNoOutstandingExpectation();
    });
  }
});
```

**Note** if you use `beforeEach` block with `element`, the `beforeEach` runs *before* the element
is created. This gives you a chance to setup mocks before running the element and possibly making calls.
If you really want to control when an element is created use `exposeApi` option 
(see [Secondary options](#secondary-options)).

### Mocking

#### Mock value provided by a module

Often during testing we need to mock something provided by a module, even if it is 
passed via dependency injection. ng-describe makes it very simple. List all modules with values 
to be mocked in `mocks` object property.

```js
// C.js
angular.module('C', ['A'])
  .service('getFoo', function (foo) {
    // foo is provided by module A
    return function getFoo() {
      return foo;
    };
  });
// C-spec.js
ngDescribe({
  name: 'test C with mocking top level',
  modules: ['C'],
  inject: ['getFoo'],
  mocks: {
    // replace C.getFoo with mock function that returns 11
    C: {
      getFoo: function () {
        return 11;
      }
    }
  },
  verbose: false,
  tests: function (deps) {
    it('has mock injected value', function () {
      var result = deps.getFoo();
      la(result === 11, 'we got back mock value', result);
    });
  }
});
```

Remember when making mocks, it is always `module name : provider name : mocked property name`

```js
mocks: {
  'module name': {
    'mocked provider name': {
      'mocked value name'
    }
  }
}
```

Note: the mocked values are injected using `$provider.constant` call to be able to override both
values and constants

```js
angular.module('A10', [])
  .constant('foo', 'bar');
ngDescribe({
  modules: 'A10',
  mock: {
    A10: {
      foo: 42
    }
  },
  inject: 'foo',
  tests: function (deps) {
    it('has correct constant foo', function () {
      expect(deps.foo).toEqual(42);
    });
  }
});
```

You can even mock part of the module itself and use mock value in other parts via injection

```js
angular.module('LargeModule', [])
  .constant('foo', 'foo')
  .service('getFoo', function (foo) {
    return function getFoo() {
      return foo;
    };
  });
ngDescribe({
  name: 'mocking part of the module itself',
  modules: 'LargeModule',
  inject: 'getFoo',
  mock: {
    LargeModule: {
      foo: 'bar'
    }
  },
  tests: function (deps) {
    it('service injects mock value', function () {
      la(deps.getFoo() === 'bar', 'returns mock value');
    });
  }
});
```

#### Angular services inside mocks

You can use other injected dependencies inside mocked functions, using
injected values and free parameters.

```js
ngDescribe({
  inject: ['getFoo', '$rootScope'],
  mocks: {
    C: {
      // use angular $q service in the mock function
      // argument "value" remains free
      getFoo: function ($q, value) {
        return $q.when(value);
      }
    }
  },
  tests: function (deps) {
    it('injected $q into mock', function (done) {
      deps.getFoo('foo').then(function (result) {
        expect(result).toEqual('foo');
        done();
      });
      deps.$rootScope.$apply(); // resolve promise
    });
  }
});
```

#### Mock $http.get

Often we need some dummy response from `$http.get` method. We can use mock `httpBackend` 
or mock the `$http` object. For example to always return mock value when making any GET request,
we can use

```js
mocks: {
  ng: {
    $http: {
      get: function ($q, url) {
        // inspect url if needed
        return $q.when({
          data: {
            life: 42
          }
        });
      }
    }
  }
}
```

`$http` service returns a promise that resolves with a *response* object. The actual result to send
is placed into the `data` property, as I show here.

#### Mock http responses

You can use a shortcut to define mock HTTP responses via `$httpBackend` module. For example,
you can define static responses.

```js
ngDescribe({
  http: {
    get: {
      '/some/url': 42,
      '/some/other/url': [500, 'something went wrong']
    },
    post: {
      // you can use custom functions too
      '/some/post/url': function (method, url, data, headers) {
        return [200, 'ok'];
      }
    }
  }
});
```
All HTTP methods are supported (`get`, `post`, `delete`, `put`, etc.).

You can also get a function that would return a config object.

```js
var mockGetApi = {
  '/some/url': 42
};
mockGetApi['/some/other/url'] = [500, 'not ok'];
ngDescribe({
  http: {
    get: mockGetApi
  }
});
```

You can use `deps.http.flush()` to move the http responses along.

You can return the entire http mock object from a function, or combine objects with functions.

```js
function constructMockApi() {
  return {
    get: function () {
      return { '/my/url': 42 };
    },
    post: {
      '/my/other/url': [200, 'nice']
    }
  };
}
ngDescribe({
  http: constructMockApi,
  test: function (deps) {
    ...
  } 
});
```

You can use exact query arguments too

```js
http: {
  get: {
    '/foo/bar?search=value': 42,
    '/foo/bar?search=value&something=else': 'foo'
  }
}
// $http.get('/foo/bar?search=value') will resolve with value 42
// $http.get('/foo/bar?search=value&something=else') will resolve with value 'foo'
```

or you can build the query string automatically by passing `params` property in the request config
objet

```js
http: {
  get: {
    '/foo/bar?search=value&something=else': 'foo'
  }
}
// inside the unit test
var config = {
  params: {
    search: 'value',
    something: 'else'
  }
};
$http.get('/foo/bar', config).then(function (response) {
  // response.data = 'foo'
});
```

**note** the `http` mocks are defined using `$httpBack.when(method, ...)` calls, 
which are looser than `$httpBackend.expect(method, ...)`, 
see [ngMock/$httpBackend](https://docs.angularjs.org/api/ngMock/service/$httpBackend).

### Spying

#### Spy on injected methods

One can quickly spy on injected services (or other methods) using [sinon.js](http://sinonjs.org/) 
similarly to [spying on the regular JavaScript methods](http://glebbahmutov.com/blog/spying-on-methods/).

* Include a browser-compatible combined [sinon.js build](http://sinonjs.org/releases/sinon-1.12.1.js) 
into the list of loaded Karma files.
* Setup spy in the `beforeEach` function. Since every injected service is a method on the `deps`
object, the setup is a single command.
* Restore the original method in `afterEach` function.

```js
// source code
angular.module('Tweets', [])
  .service('getTweets', function () {
    return function getTweets(username) {
      console.log('returning # of tweets for', username);
      return 42;
    };
  });
```

```js
// spec
ngDescribe({
  name: 'spying on Tweets getTweets service',
  modules: 'Tweets',
  inject: 'getTweets',
  tests: function (deps) {
    beforeEach(function () {
      sinon.spy(deps, 'getTweets');
    });
    afterEach(function () {
      deps.getTweets.restore();
    });
    it('calls getTweets service', function () {
      var n = deps.getTweets('foo');
      la(n === 42, 'resolved with correct value');
      la(deps.getTweets.called, 'getTweets was called (spied using sinon)');
      la(deps.getTweets.firstCall.calledWith('foo'));
    });
  }
});
```

#### Spy on injected function

You can inject a function, but use a [Sinon spy](http://sinonjs.org/docs/#spies) instead
of the injected function to get additional information. For example, to spy on the `$filter uppercase`,
we can use the following code.

```js
ngDescribe({
  name: 'spying on a filter',
  inject: '$filter',
  tests: function (deps) {
    /*
      to spy on a injected filter, need to grab the actual filter function
      and then create a spy
    */
    // _uppercase = angular uppercase $filter
    // uppercase = spy on the _uppercase
    var _uppercase, uppercase;
    beforeEach(function () {
      _uppercase = deps.$filter('uppercase');
      uppercase = sinon.spy(_uppercase);
    });
    it('converts string to uppercase', function () {
      var result = uppercase('foo');
      la(result === 'FOO', 'converted string to uppercase', result);
      la(uppercase.calledOnce, 'uppercase was called once');
      la(uppercase.calledWith('foo'));
    });
  }
});
```

#### Spy on 3rd party service injected some place else

Let us say you need to verify that the `$interval` service injected in the module under test
was called. It is a little verbose to verify from the unit test. We must mock the `$interval`
with our function and then call the actual `$interval` from the module `ng` to provide the
same functionality.

Source code we are trying to unit test

```js
angular.module('IntervalExample', [])
  .service('numbers', function ($interval, $rootScope) {
    return function emitNumbers(delay, n) {
      var k = 0;
      $interval(function () {
        $rootScope.$emit('number', k);
        k += 1;
      }, 100, n);
    };
  });
```

In the unit test we will mock `$interval` service for module `IntervalExample`

```js
// unit test start
var intervalCalled;
ngDescribe({
  name: 'spying on $interval',
  module: 'IntervalExample',
  inject: ['numbers', '$rootScope'],
  verbose: false,
  only: false,
  mocks: {
    IntervalExample: {
      $interval: function mockInterval(fn, delay, n) {
        var injector = angular.injector(['ng']);
        var $interval = injector.get('$interval');
        intervalCalled = true;
        return $interval(fn, delay, n);
      }
    }
  },
  tests: function (deps) {
    // unit test goes here
  }
});
```

A unit test just calls the `numbers` function and then checks the variable `intervalCalled`

```js
it('emits 3 numbers', function (done) {
  deps.$rootScope.$on('number', function (event, k) {
    if (k === 2) {
      done();
    }
  });
  // emit 3 numbers with 100ms interval
  deps.numbers(100, 3);
  la(intervalCalled, 'the $interval was called somewhere');
});
```

You can see the unit test in file [test/spying-on-interval-spec.js](test/spying-on-interval-spec.js).

#### Spy on mocked service

If we mock an injected service, we can still spy on it, just like as if we were spying on the
regular service. For example, let us take the same method as above and mock it.

```js
angular.module('Tweets', [])
  .service('getTweets', function () {
    return function getTweets(username) {
      return 42;
    };
  });
```

The mock will return a different number.

```js
ngDescribe({
  name: 'spying on mock methods',
  inject: 'getTweets',
  mocks: {
    Tweets: {
      getTweets: function (username) {
        return 1000;
      }
    }
  },
  tests: function (deps) {
    beforeEach(function () {
      sinon.spy(deps, 'getTweets');
    });
    afterEach(function () {
      deps.getTweets.restore();
    });
    it('calls mocked getTweets service', function () {
      var n = deps.getTweets('bar');
      la(n === 1000, 'resolved with correct value from the mock service');
      la(deps.getTweets.called,
        'mock service getTweets was called (spied using sinon)');
      la(deps.getTweets.firstCall.calledWith('bar'),
        'mock service getTweets was called with expected argument');
    });
  }
});
```

### Configure module

If you use a separate module with namesake provider to pass configuration into the modules
(see [Inject valid constants into Angular](http://glebbahmutov.com/blog/inject-valid-constants-into-angular/)),
you can easily configure these modules.

```js
angular.module('App', ['AppConfig'])
  .service('foo', function (AppConfig) {
    return function foo() {
      return GConfig.bar;
    };
  });
// config module has provider with same name
angular.module('AppConfig', [])
  .provider('AppConfig', function () {
    var config = {};
    return {
      set: function (settings) {
        config = settings;
      },
      $get: function () {
        return config;
      }
    };
  });
// spec file
ngDescribe({
  name: 'config module example',
  modules: 'App',
  inject: 'foo',
  configs: {
    // every config module will be loaded automatically
    AppConfig: {
      bar: 'boo!'
    }
  },
  tests: function (deps) {
    it('foo has configured bar value', function () {
      expect(deps.foo()).toEqual('boo!');
    });
  }
});
```

You can configure multiple modules at the same time. Note that during the configuration
Angular is yet to be loaded. Thus you cannot use Angular services inside the configuration blocks.

### Helpful failure messages

ng-describe works inside [helpDescribe function](https://github.com/bahmutov/lazy-ass-helpful#lazy-ass-helpful-bdd),
producing meaningful error messages on failure (if you use [lazy assertions](https://github.com/bahmutov/lazy-ass)).

```js
helpDescribe('ngDescribe inside helpful', function () {
  ngDescribe({
    name: 'example',
    tests: function () {
      it('gives helpful error message', function () {
        var foo = 2, bar = 3;
        la(foo + bar === 4); // wrong on purpose
      });
    }
  });
});
```
when this test fails, it generates meaningful message with all relevant information: the expression
that fails `foo + bar === 4` and runtime values of `foo` and `bar`.

    PhantomJS 1.9.7 (Mac OS X) 
    ட ngDescribe inside helpful 
      ட example 
        ட ✘ gives helpful error message FAILED
      Error: condition [foo + bar === 4] foo: 2 bar: 3
          at lazyAss (/ng-describe/node_modules/lazy-ass/index.js:57)
    PhantomJS 1.9.7 (Mac OS X): Executed 37 of 38 (1 FAILED) (skipped 1) (0.053 secs / 0.002 secs)


## Development

To build the README document, run unit tests and linter

    npm run build

To run all unit tests (against different Angular versions)

    npm test

To keep a watch and rerun build + lint + tests on source file change

    npm run watch

For now, all source is in a single `ng-describe.js` file, while the documentation
is generated from Markdown files in the `docs` folder

To just run karma unit tests via Grunt plugin

    npm run karma

If you have Karma runner installed globally you can run all the unit tests yourself ones

    karma start --single-run=true test/karma.conf.js

### Updating dependencies

This project uses a lot of 3rd party dependencies that constantly get out of date.
To reliably update dependencies to the latest working versions, we use
[next-update](https://github.com/bahmutov/next-update). There is already a script command

    npm run update-dependencies

You can upgrade a particular dependency by adding "-m <name>", for example

    npm run update-dependencies -- -m jscs

If you use [npm-quick-run](https://github.com/bahmutov/npm-quick-run) you can use shorthand

    nr u -m jscs



## Modules used
* [check-more-types](https://github.com/kensho/check-more-types) - Large collection of predicates.
* [lazy-ass](https://github.com/bahmutov/lazy-ass) - Lazy assertions without performance penalty


## License

Author: Kensho &copy; 2014

* [@kensho](https://twitter.com/kensho)
* [kensho.com](http://kensho.com)

Support: if you find any problems with this library,
[open issue](https://github.com/kensho/ng-describe/issues) on Github


The MIT License (MIT)

Copyright (c) 2014 Kensho

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.