Robust Error Handling in an Angular Service

Angular applications often interact with external APIs or perform operations that can fail. Implementing robust error handling is crucial for providing a good user experience and preventing unexpected application crashes. This challenge asks you to build an Angular service that fetches data from a mock API and gracefully handles potential errors, displaying informative messages to the user.

Problem Description

You need to create an Angular service called DataService that fetches user data from a mock API endpoint. The API might return successful responses, network errors, or server-side errors (simulated by occasionally returning a 500 status code). Your service should:

1. Fetch Data: Make an HTTP GET request to the mock API endpoint https://jsonplaceholder.typicode.com/users.
2. Handle Success: If the request is successful (status code 200-299), the service should return the fetched data.
3. Handle Network Errors: If a network error occurs (e.g., no internet connection), the service should display an appropriate error message to the user, such as "Network error. Please check your connection."
4. Handle Server Errors: If the server returns an error (status code 500), the service should display a user-friendly error message, such as "Server error. Please try again later."
5. Handle Other Errors: For any other error codes, display a generic error message like "An unexpected error occurred."
6. Use Observables: The service should return an Observable<any> to handle asynchronous operations and error propagation.
7. Provide Error Messages: The error messages should be displayed to the user in a clear and understandable way. (While the challenge doesn't require a UI component, assume the error messages will be displayed in one).

Examples

Example 1:

Input: Successful API response with user data.
Output: Observable emitting the user data.
Explanation: The service successfully fetches and returns the data.

Example 2:

Input: Network error (e.g., no internet connection).
Output: Observable emitting an error with the message "Network error. Please check your connection."
Explanation: The service detects the network error and returns a relevant error message.

Example 3:

Input: API returns a 500 Internal Server Error.
Output: Observable emitting an error with the message "Server error. Please try again later."
Explanation: The service handles the server error and provides a user-friendly message.

Constraints

• The service must use Angular's HttpClient for making HTTP requests.
• The service must return an Observable<any>.
• Error messages must be informative and user-friendly.
• The mock API endpoint https://jsonplaceholder.typicode.com/users is considered reliable for testing successful scenarios. You should simulate the 500 error for testing purposes.
• The service should not throw exceptions directly; it should propagate errors through the Observable.

Notes

• Consider using the catchError operator in RxJS to handle errors within the Observable stream.
• You can simulate a 500 error by manually throwing an error within the catchError block or by using a mock HTTP backend for testing.
• Think about how to provide consistent error handling across your application.
• Focus on the error handling logic; the exact UI display of the error messages is not required for this challenge. Assume a component will subscribe to the observable and display the error.