问题
I feel I am missing something crucial in this extremely simplified angular directive unit test:
import * as angular from 'angular'
import 'angular-mocks'
const app = angular.module('my-app', [])
app.directive('myDirective', () => ({
template: 'this does not work either',
link: (scope, element) => { // have also tried compile fn
console.log('This does not log')
element.html('Hi!')
}
}))
describe('myDirective', () => {
var element, scope
beforeEach(app)
beforeEach(inject(($rootScope, $compile) => {
scope = $rootScope.$new()
element = $compile('<my-directive />')(scope)
scope.$digest()
}))
it('should actually do something', () => {
expect(element.html()).toEqual('Hi!')
})
})
When jest runs it appears the directive has not been linked/compiled/whatever
FAIL test/HtmlToPlaintextDirective.spec.js
● myDirective › should actually do something
expect(received).toEqual(expected)
Expected value to equal:
"Hi!"
Received:
""
回答1:
Updated answer:
You're right things don't work as expected when importing everything in a single file.
Digging into things it looks like you're running into some magic that Babel/Jest does to support browser scripts that rely on globals (like AngularJS).
What's happening is that your module's angular
variable is not the same as the global angular
variable that is visible to angular-mocks.
You can check this by running this at the top of one of your tests:
import * as angular from 'angular'
import 'angular-mocks'
console.log(angular === window.angular); // `false` in Jest!
console.log(angular.mock); // undefined
console.log(window.angular.mock); // `{...}` defined
To work around this you just need to use the global angular
variable in your tests.
src/__test__/all-in-one.test.js:
import "angular";
import "angular-mocks";
/*
Work around Jest's window/global mock magic.
Use the global version of `angular` that has been augmented by angular-mocks.
*/
var angular = window.angular;
export var app = angular.module('app', []);
app.directive('myDirective', () => ({
link: (scope, element) => {
console.log('This does log');
scope.content = 'Hi!';
},
template: 'content: {{content}}'
}));
describe('myDirective', function(){
var element;
var scope;
beforeEach(function(){
angular.mock.module(app.name);
});
it('should do something', function(){
inject(function(
$rootScope,
$compile
){
scope = $rootScope.$new();
element = $compile('<my-directive></my-directive>')(scope);
scope.$digest();
});
expect(element.html()).toEqual('content: Hi!');
});
});
Original answer: (This worked because I was accidentally using the global version of angular
inside my test.)
The Angular module under test isn't being initialised correctly in your tests.
Your call to beforeEach(app)
isn't correct.
Instead you need to use angular.mock.module("moduleName")
to initialise your module.
describe('myDirective', () => {
var element, scope
// You need to pass the module name to `angular.mock.module()`
beforeEach(function(){
angular.mock.module(app.name);
});
// Then you can set up and run your tests as normal:
beforeEach(inject(($rootScope, $compile) => {
scope = $rootScope.$new()
element = $compile('<my-directive></my-directive>')(scope)
scope.$digest()
}))
it('should actually do something', () => {
expect(element.html()).toEqual('Hi!')
})
});
And then your test works as expected for me:
PASS src\__test__\app.test.js
myDirective
√ should do something (46ms)
For reference, here is the full app and test:
src/app/app.module.js:
import * as angular from 'angular'
export var app = angular.module('app', []);
app.directive('myDirective', () => ({
link: (scope, element) => {
console.log('This does log');
scope.content = 'Hi!';
},
template: 'content: {{content}}'
}))
src/__test__/app.test.js:
import {app} from "../app/app.module";
import "angular-mocks";
describe('myDirective', function(){
var element;
var scope;
beforeEach(function(){
angular.mock.module(app.name);
});
beforeEach(inject(function(
$rootScope,
$compile
){
scope = $rootScope.$new();
element = $compile('<my-directive></my-directive>')(scope);
scope.$digest();
}));
it('should do something', function(){
expect(element.html()).toEqual('content: Hi!');
});
});
回答2:
I ran into the same baffling behavior a couple years later and I wanted to share what I found
If you transpile the test using babel and look at the imports you will find something similar to the following
var _interopRequireWildcard = require("@babel/runtime/helpers/interopRequireWildcard");
var angular = _interopRequireWildcard(require("angular"));
require("angular-mocks");
_interopRequireWildcard
currently has the following implementation
function _interopRequireWildcard(obj) {
if (obj && obj.__esModule) {
return obj;
} else {
var newObj = {};
if (obj != null) {
for (var key in obj) {
if (Object.prototype.hasOwnProperty.call(obj, key)) {
var desc = Object.defineProperty && Object.getOwnPropertyDescriptor ? Object.getOwnPropertyDescriptor(obj, key) : {};
if (desc.get || desc.set) {
Object.defineProperty(newObj, key, desc);
} else {
newObj[key] = obj[key];
}
}
}
}
newObj.default = obj;
return newObj;
}
}
In short it creates a new object and copies all the properties from the imported object. This is why angular === window.angular
is false
. It also explains why angular.mock
isn't defined, it didn't exist when _interopRequireWildcard
made a copy of the module
Given that there are a couple additional ways to solve the problem in addition to the accepted answer
Instead of using import * as angular from 'angular'
using import angular from 'angular'
should avoid the behavior because _interopRequireDefault
does not return a different object. (However, if you are using TypeScript it may not resolve the types for 'angular' correctly with this method)
Another option would be to import angular twice:
import 'angular'
import 'angular-mocks'
import * as angular from 'angular'
来源:https://stackoverflow.com/questions/43110646/unit-testing-angular-directives-with-jest