Fetch middleware for throwing errors on HTTP error responses.
Automatically throws errors for HTTP responses based on status codes. By default, throws a ResponseError for any response with status >= 400. Provides flexible customization through status-specific mappers and configurable thresholds, enabling standardized error handling across your application.
Intended for use with @qfetch/core.
npm install @qfetch/middleware-response-error
import { withResponseError, ResponseError } from '@qfetch/middleware-response-error';
import { withRetryStatus } from '@qfetch/middleware-retry-status';
import { withBaseUrl } from '@qfetch/middleware-base-url';
import { upto, zero } from '@proventuslabs/retry-strategies';
import { compose } from '@qfetch/core';
// Custom application errors
class NotFoundError extends Error {
constructor(public url: string) {
super(`Resource not found: ${url}`);
this.name = 'NotFoundError';
}
}
// API client with custom error handling
const api = compose(
withResponseError({
statusMap: new Map([
[404, (res) => new NotFoundError(res.url)],
[400, async (res) => {
const body = await res.json();
return new Error(`Validation failed: ${body.message}`);
}],
]),
}),
withRetryStatus({ strategy: () => upto(3, zero()) }),
withBaseUrl('https://api.example.com/v1/'),
)(fetch);
try {
const user = await api('users/123').then(r => r.json());
} catch (error) {
if (error instanceof NotFoundError) {
// Handle 404 specifically
} else if (error instanceof ResponseError) {
// Handle other HTTP errors (500, etc.)
console.log(error.status, error.statusText);
}
}
For complete API reference, examples, and type definitions, see the API documentation.