You are writing a test for an Angular component that renders a list of items. You want to test that when a new item is added, it is correctly displayed in the component. Which testing technique or utility would be best suited for this?
- End-to-End Testing with Protractor
- Integration Testing with Karma and Jasmine
- No testing needed - it's an Angular feature
- Unit Testing with TestBed
For testing component behavior in isolation, Unit Testing with TestBed is the most suitable approach. It allows you to create an isolated testing environment for the component.
The _____ method in a Route Guard is used to check whether a user can navigate to a specific route.
- canActivate
- canDeactivate
- canNavigateTo
- checkRouteAccess
The canActivate method in a Route Guard is used to check whether a user can navigate to a specific route by returning true or false based on certain conditions.
What is the primary purpose of Dependency Injection (DI) in Angular?
- Define component behavior
- Enable two-way data binding
- Handle HTTP requests
- Manage external dependencies
The primary purpose of Dependency Injection (DI) in Angular is to manage external dependencies by providing them to a component when it's created.
What are the implications of importing a module that provides a service into multiple feature modules?
- Compilation error
- Multiple service instances
- No implications
- Shared singleton service instance
Importing a module with a service into multiple feature modules results in a shared singleton service instance, allowing data to be shared.
How does Angular Universal improve the perceived performance of an application?
- It enhances routing performance
- It improves code quality
- It reduces the bundle size
- It speeds up the initial rendering of a page
Angular Universal improves the perceived performance of an application by speeding up the initial rendering of a page on the server side.
In an Angular application, you want to ensure that data for a specific route is fetched and ready before the route is activated. How would you achieve this?
- Configure route preloading strategies to ensure data is available before route activation.
- Fetch data in the route component's constructor and use a loading spinner until it's available.
- Implement a global data service to fetch data, and check data availability in the route's lifecycle hooks.
- Use route resolvers to fetch and resolve the data before activating the route.
To ensure that data for a specific route is fetched and ready before the route is activated, you should use route resolvers. Resolvers fetch and resolve the data before activating the route, ensuring the data is available when the route component is initialized.
In Angular, the replaceUrl property of the _____ object can be used to navigate while replacing the current URL in the browser's history.
- ActivatedRouteSnapshot
- NavigationExtras
- Router
- RouterStateSnapshot
In Angular, the replaceUrl property of the RouterStateSnapshot object can be used to navigate while replacing the current URL in the browser's history. It allows for URL manipulation.
When testing a directive that modifies the DOM, what should you consider to ensure that the tests are not flaky?
- Avoid testing such directives as they are inherently flaky
- Check for DOM changes in a loop until they are detected consistently
- Use a stubbed version of the directive to isolate DOM changes
- Use asynchronous timers to delay test execution until the DOM changes
To prevent flaky tests when testing a directive that modifies the DOM, use a stubbed version of the directive to isolate DOM changes and ensure reliable testing.
What does the async pipe do in an Angular template?
- Handles routing
- Renders HTML
- Subscribes to an Observable
- Transforms data
The async pipe in an Angular template subscribes to an Observable and automatically updates the view with the most recent data emitted by the Observable. It simplifies working with asynchronous data in templates.
Which lifecycle hook is best suited to react to changes in a component's input properties?
- ngAfterViewInit
- ngDoCheck
- ngOnChanges
- ngOnInit
The ngOnChanges lifecycle hook is best suited to react to changes in a component's input properties. It provides information about the changes to input properties.