🚫
Never Throws
All errors are returned as values, not exceptions. No more try-catch blocks or unexpected throws.
Typed FetchType-safe HTTP client that never throws
Inspired by Go's error handling pattern, built on top of the native Fetch API
Inspired by Go's error handling pattern, built on top of the native Fetch API
import { typedFetch, NotFoundError, UnauthorizedError, NetworkError } from '@pbpeterson/typed-fetch';
interface User {
id: number;
name: string;
email: string;
}
// Specify expected client errors for better type safety
type ExpectedErrors = NotFoundError | UnauthorizedError;
const { response, error } = await typedFetch<User[], ExpectedErrors>('/api/users');
if (error) {
// Here, response is null and error contains the specific error
if (error instanceof NotFoundError) {
console.log('Users not found');
} else if (error instanceof UnauthorizedError) {
console.log('Authentication required');
} else if (error instanceof NetworkError) {
console.log('Network error:', error.message);
} else {
// Server errors (5xx) are always included
console.log(`HTTP ${error.status}: ${error.statusText}`);
}
} else {
// Here, error is null and response contains the successful result
const users = await response.json(); // Type: User[]
console.log('Users:', users);
}Traditional fetch libraries throw exceptions on HTTP errors, making error handling cumbersome and error-prone. typed-fetch follows Go's philosophy of explicit error handling - errors are values, not exceptions.
try {
const response = await fetch('/api/users');
const users = await response.json(); // What if response is 404?
} catch (error) {
// Handle network errors, parsing errors, HTTP errors... all mixed together
}import { NotFoundError, UnauthorizedError } from '@pbpeterson/typed-fetch';
// Specify expected errors for better type safety
type ExpectedErrors = NotFoundError | UnauthorizedError;
const { response, error } = await typedFetch<User[], ExpectedErrors>('/api/users');
if (error) {
// Here: error has the specific error, response is null
if (error instanceof NotFoundError) {
console.log('Users endpoint not found');
} else if (error instanceof UnauthorizedError) {
console.log('Authentication required');
} else {
console.log(`Server error ${error.status}: ${error.statusText}`);
}
const errorDetails = await error.json(); // Access error response body
} else {
// Here: response has the data, error is null
// TypeScript knows response is not null
const users = await response.json(); // Type: User[]
}npm install @pbpeterson/typed-fetchpnpm add @pbpeterson/typed-fetchyarn add @pbpeterson/typed-fetchCheck out the Getting Started guide to learn how to use typed-fetch in your project.