Creating a Generic API Client Wrapper for Reusability

class ApiClient {
    constructor(baseURL, defaultHeaders = {}) {
        this.baseURL = baseURL;
        this.defaultHeaders = {
            'Content-Type': 'application/json',
            ...defaultHeaders,
        };
    }

    async request(endpoint, options = {}) {
        const url = `${this.baseURL}${endpoint}`;
        const config = {
            ...options,
            headers: {
                ...this.defaultHeaders,
                ...options.headers,
            },
        };

        try {
            const response = await fetch(url, config);
            if (!response.ok) {
                const errorData = await response.json().catch(() => ({ message: response.statusText }));
                throw new Error(errorData.message || `API error: ${response.status}`);
            }
            // Handle 204 No Content gracefully
            if (response.status === 204) {
                return null;
            }
            return await response.json();
        } catch (error) {
            console.error('API request failed:', error);
            throw error;
        }
    }

    get(endpoint, params = {}, options = {}) {
        const queryString = new URLSearchParams(params).toString();
        const fullEndpoint = queryString ? `${endpoint}?${queryString}` : endpoint;
        return this.request(fullEndpoint, { ...options, method: 'GET' });
    }

    post(endpoint, data = {}, options = {}) {
        return this.request(endpoint, {
            ...options,
            method: 'POST',
            body: JSON.stringify(data),
        });
    }

    put(endpoint, data = {}, options = {}) {
        return this.request(endpoint, {
            ...options,
            method: 'PUT',
            body: JSON.stringify(data),
        });
    }

    delete(endpoint, options = {}) {
        return this.request(endpoint, { ...options, method: 'DELETE' });
    }

    // Method to set/update default headers (e.g., for auth token)
    setAuthToken(token) {
        this.defaultHeaders['Authorization'] = `Bearer ${token}`;
    }
}

// Example Usage:
// const myApiClient = new ApiClient('https://api.example.com/v1', {
//     'X-Custom-Header': 'MyValue'
// });

// myApiClient.setAuthToken('your_jwt_token_here');

// (async () => {
//     try {
//         const users = await myApiClient.get('/users', { limit: 5 });
//         console.log('Users:', users);

//         const newUser = await myApiClient.post('/users', { name: 'Alice', email: '[email protected]' });
//         console.log('New User:', newUser);
//     } catch (error) {
//         console.error('Operation failed:', error);
//     }
// })();