When testing asynchronous operations in Angular, which utility can be used to handle asynchronous tasks inside test specs?
- ComponentFixture
- HttpClientTestingModule
- TestBed.overrideProvider()
- async()
When testing asynchronous operations in Angular, the async() function is used to handle asynchronous tasks inside test specs. It enables you to write asynchronous code in a synchronous style, making it easier to work with observables, promises, and async functions within your tests.
You are developing a multi-tenant application where each tenant may require slightly different service implementations. How can you achieve this in Angular without duplicating a lot of code?
- Create separate Angular applications for each tenant, each with its unique service implementation.
- Create separate Angular modules for each tenant with their service implementations.
- Duplicate the service code for each tenant and load the respective service based on the tenant's login.
- Use Angular dependency injection to provide different service instances based on the tenant context.
In a multi-tenant Angular application, you can use Angular's dependency injection to provide different service instances based on the tenant context. This avoids code duplication and maintains a modular and maintainable codebase. Creating separate modules for each tenant can also work but may be less dynamic and flexible than using dependency injection.
What tool is responsible for executing tests in a browser when testing Angular applications?
- Istanbul
- Jasmine
- Karma
- Protractor
Karma is a test runner tool that is responsible for executing tests in a browser when testing Angular applications. It launches the browser, captures it, and runs the tests in a real browser environment, allowing you to test your application as it would run in production.
In terms of performance optimization, why is Ahead-of-Time (AOT) compilation beneficial for Angular applications?
- AOT allows for better code splitting and lazy loading
- AOT enhances the developer experience by enabling hot module reloading
- AOT improves runtime execution speed through just-in-time compilation
- AOT reduces the bundle size by eliminating the need for the Angular compiler in the browser
Ahead-of-Time (AOT) compilation in Angular is beneficial for performance optimization because it reduces the bundle size by precompiling templates and removing the need for the Angular compiler to be shipped to the browser. Smaller bundles result in faster loading times for the application.
To dynamically create a component and attach it to a specific location in the view, you'd use the ______ along with ComponentFactoryResolver.
- ComponentLoader
- DynamicInjector
- ViewChild
- ViewContainerRef
To dynamically create and attach components in Angular, you use the ViewContainerRef along with ComponentFactoryResolver. ViewContainerRef provides access to the view where you want to insert the component, and ComponentFactoryResolver helps create and manage the component instance. ViewChild is a decorator used to access child components, but it's not directly related to creating components dynamically. ComponentLoader and DynamicInjector are not standard Angular concepts in this context.
When you want to run logic before a route's data is resolved, you should implement the Resolve<________> interface in Angular.
- Resolve
- Resolve
- Resolve
- Resolve
In Angular, when you want to run logic before a route's data is resolved, you should implement the Resolve interface. This allows you to define a resolver service that can fetch data or perform actions before the route is activated, ensuring that the required data is available when the route component is loaded.
Which method of ViewContainerRef allows you to insert a component?
- createComponent()
- deleteComponent()
- updateComponent()
- renderComponent()
The method of ViewContainerRef that allows you to insert a component is createComponent(). This method is used to create and insert a dynamic component into the specified view container. The other options are not valid methods of ViewContainerRef and do not serve the purpose of inserting components.
How can you simulate a click event on an element during Angular unit testing?
- Angular unit tests cannot simulate click events.
- By manually dispatching a click event on the DOM element.
- Using the click method provided by the TestBed utility.
- Using the simulateClick function from the @angular/testing package.
To simulate a click event on an element during Angular unit testing, you can manually dispatch a click event on the DOM element using the dispatchEvent method. This allows you to trigger the same behavior that a real user would experience when clicking the element.
The directive that's used to manipulate the structure of the DOM by adding/removing elements is prefixed with ________.
- *ngFor
- *ngIf
- *ngSwitch
- *ngStyle
The directive used to manipulate the DOM structure by adding or removing elements conditionally is prefixed with *ngIf in Angular. It allows you to control whether an element is rendered based on a given condition. The other options, like *ngFor, *ngSwitch, and *ngStyle, are used for different purposes in Angular and do not add or remove elements from the DOM.
What would you use to capture and act upon route parameters passed in a URL in Angular?
- ActivatedRouteSnapshot and RouteParams
- Router and ActivatedRoute
- ActivatedRoute and Router
- RouteData and RouteSnapshot
To capture and act upon route parameters in Angular, you would use ActivatedRouteSnapshot and RouteParams. These are part of the Angular Router and provide access to the parameters passed in the URL, allowing you to utilize them in your components. The other options may be components of the Angular Router, but they are not the primary tools for capturing and acting upon route parameters.