TypeScript Question
Jasmine: Testing a function returning a promise
I am writing tests using Jasmine for my angular application. All the tests are passing. My class looks like follows:
class xyz implements ng.IComponentController {
private myList: ng.IPromise<MyList[]> ;
//declare necessary variables
/* @ngInject */
constructor(private ListService: ListService,
) {
this.myList = this.ListService.getList();
}
public onChange(): void {
this.isNameUnique(this.name).then(function(unique){
scope.isUnique = unique;
scope.errorNameInput = !reg.test(scope.name) || !scope.isUnique;
scope.myFunction({
//do something
});
});
}
public isNameUnique(name: string): ng.IPromise<boolean> {
return this.myList
.then(
(names) => {
_.mapValues(names, function(name){
return name.uuid.toLowerCase();
});
return (_.findIndex(names, { uuid : uuid.toLowerCase() }) === -1) ? true : false;
});
}
}
Here, I am using ListService to pre-populate my list in the constructor itself (so it calls the service only once). Then, in my onChange method, I am checking
if a name is unique or not. The isNameUnique is returning a boolean promise.
Now, I'm trying to get 100% coverage for my test. I'm getting confused about testing isNameUnique method here. My first test is:
(Assuming myList is a json similar to response I will get from service)
this.$scope.myFunction = jasmine.createSpy('myFunction');
it('should ...', function() {
this.view.find(NAME_INPUT).val('blue').change(); // my view element.
this.getList.resolve(myList);
this.controller.isNameUnique('blue').then(function (unique) {
expect(unique).toEqual(false); //since blue is already in my json
expect(this.controller.errorNameInput).toEqual(true); //since its not unique, errornameinput will be set to true
expect(this.$scope.myFunction).toHaveBeenCalled();
});
});
I would expect this test to cover the line:
scope.errorNameInput = !reg.test(scope.name) || !scope.isUniquemyFunction()Please let me know if you see anything else wrong since I'm quite new to Angular and Jasmine. Thanks.
Answer Source
You need to call $scope.$digest() to cause your promise to resolve in your test. There is a handy tutorial that discusses this in depth here
Hope that helps!