Fetching and Displaying Asynchronous Data in a Vue Component

This challenge focuses on implementing asynchronous data fetching within a Vue.js component using TypeScript. You'll need to manage loading states, potential errors, and display the fetched data effectively, simulating a common real-world scenario.

Problem Description

Your task is to create a Vue.js component that fetches data from a mock API endpoint asynchronously. This component should gracefully handle the different states of the asynchronous operation: loading, success, and error. The fetched data, which represents a list of users, should be displayed in a user-friendly manner.

Key Requirements:

• Asynchronous Data Fetching: Implement a function to fetch data (e.g., from a mock API). This function should simulate network latency.
• State Management: Manage three distinct states for the data fetching process:
  • loading: While the data is being fetched.
  • data: Once the data has been successfully fetched.
  • error: If an error occurs during fetching.
• Display Logic: Conditionally render UI elements based on the current state:
  • Show a "Loading..." message when loading is true.
  • Display the fetched user list when data is available and error is null.
  • Show an error message when error is present.
• TypeScript Integration: Utilize TypeScript for strong typing of component data, props (if any), and the fetched data.

Expected Behavior:

When the component mounts, it should immediately initiate the data fetching process. Initially, a loading indicator will be displayed. If the fetch is successful, the list of users will be rendered. If an error occurs, an informative error message will be shown.

Edge Cases:

• Network Error: Simulate a network error during the data fetch.
• Empty Data: Handle cases where the API returns an empty list of users.

Examples

Example 1: Successful Data Fetch

• Input: (Component mounts and mock API successfully returns user data)
• Output:

  <div>
    <h2>User List</h2>
    <ul>
      <li>John Doe</li>
      <li>Jane Smith</li>
      <li>Peter Jones</li>
    </ul>
  </div>
  

• Explanation: The component fetches user data, and upon successful retrieval, displays the names of the users in an unordered list.

Example 2: Loading State

• Input: (Component mounts, data fetching is in progress)
• Output:

  <div>
    <p>Loading users...</p>
  </div>
  

• Explanation: Before the data is ready or if an error occurs, a loading message is displayed.

Example 3: Error State

• Input: (Component mounts, mock API simulates a network error)
• Output:

  <div>
    <p>Error fetching users: Network Error</p>
  </div>
  

• Explanation: If an error occurs during data fetching (e.g., a simulated network issue), an error message is displayed to the user.

Constraints

• The mock API simulation should introduce a random delay between 500ms and 2000ms.
• The mock API should have a 10% chance of returning an error.
• The data structure for a single user will be { id: number; name: string; }.
• The fetched data will be an array of these user objects.

Notes

• Consider using Vue's Composition API (setup function) for managing reactive state and lifecycle hooks.
• A common pattern for handling asynchronous operations in Vue is to use ref for reactive variables and onMounted for initiating the fetch.
• You'll need to create a mock API function that returns a Promise to simulate asynchronous behavior and allow for error simulation.
• Think about how to type the fetched data to ensure type safety throughout your component.