Managing Dynamic API Versioning in a JavaScript Client

class ApiClient {
  constructor(baseUrl, defaultVersion = 'v1') {
    this.baseUrl = baseUrl;
    this.version = defaultVersion;
  }

  setVersion(newVersion) {
    if (!newVersion || typeof newVersion !== 'string') {
      console.error("Invalid API version provided. Keeping current version.");
      return;
    }
    this.version = newVersion;
    console.log(`API client version set to: ${this.version}`);
  }

  getEndpoint(path) {
    // Example: https://api.example.com/v1/users
    // Example: https://api.example.com/v2/products
    return `${this.baseUrl}/${this.version}/${path.startsWith('/') ? path.substring(1) : path}`;
  }

  async fetchData(path, options = {}) {
    const url = this.getEndpoint(path);
    try {
      const response = await fetch(url, options);
      if (!response.ok) {
        throw new Error(`HTTP error! Status: ${response.status}`);
      }
      return await response.json();
    } catch (error) {
      console.error(`Failed to fetch from ${url}:`, error);
      throw error;
    }
  }
}

// Usage example:
// const client = new ApiClient('https://api.example.com');

// // Fetch data using default v1
// client.fetchData('users')
//   .then(data => console.log('Users (v1):', data))
//   .catch(err => console.error(err));

// // Switch to v2
// client.setVersion('v2');
// client.fetchData('products/123')
//   .then(data => console.log('Product (v2):', data))
//   .catch(err => console.error(err));

// // Trying to fetch with an invalid version
// client.setVersion(null);
// client.fetchData('orders')
//   .then(data => console.log('Orders (still v2):', data))
//   .catch(err => console.error(err));