Error Classes

All HTTP error classes extend BaseHttpError (which extends Error).

BaseHttpError

Abstract base class for all HTTP errors.

Properties

Property	Type	Description
status	literal (e.g. 404)	HTTP status code
statusText	literal (e.g. "Not Found")	HTTP status text
headers	Headers	Response headers
name	string	Error class name (e.g. "NotFoundError")

Methods

Method	Return Type	Description
json<T = unknown>()	Promise<T>	Parse response body as JSON with optional type parameter
text()	Promise<string>	Parse response body as text
blob()	Promise<Blob>	Parse response body as Blob
arrayBuffer()	Promise<ArrayBuffer>	Parse response body as ArrayBuffer
clone()	Same class	Clone the error for multiple body reads

Static Properties

All error classes also have static status and statusText:

import { NotFoundError } from '@pbpeterson/typed-fetch';

NotFoundError.status;     // 404 (literal type)
NotFoundError.statusText; // "Not Found" (literal type)

NetworkError

Represents a network-level failure (DNS, connection refused, timeout). Unlike HTTP errors, NetworkError has no status, headers, or response body — the request never reached the server.

import { NetworkError } from '@pbpeterson/typed-fetch';

const error = new NetworkError('Connection refused');
error.name;    // "NetworkError"
error.message; // "Connection refused"

Client Errors (4xx)

Class	Status	Status Text
BadRequestError	400	Bad Request
UnauthorizedError	401	Unauthorized
PaymentRequiredError	402	Payment Required
ForbiddenError	403	Forbidden
NotFoundError	404	Not Found
MethodNotAllowedError	405	Method Not Allowed
NotAcceptableError	406	Not Acceptable
ProxyAuthenticationRequiredError	407	Proxy Authentication Required
RequestTimeoutError	408	Request Timeout
ConflictError	409	Conflict
GoneError	410	Gone
LengthRequiredError	411	Length Required
PreconditionFailedError	412	Precondition Failed
RequestTooLongError	413	Payload Too Large
RequestUriTooLongError	414	URI Too Long
UnsupportedMediaTypeError	415	Unsupported Media Type
RequestedRangeNotSatisfiableError	416	Range Not Satisfiable
ExpectationFailedError	417	Expectation Failed
ImATeapotError	418	I'm a teapot
MisdirectedRequestError	421	Misdirected Request
UnprocessableEntityError	422	Unprocessable Entity
LockedError	423	Locked
FailedDependencyError	424	Failed Dependency
TooEarlyError	425	Too Early
UpgradeRequiredError	426	Upgrade Required
PreconditionRequiredError	428	Precondition Required
TooManyRequestsError	429	Too Many Requests
RequestHeaderFieldsTooLargeError	431	Request Header Fields Too Large
UnavailableForLegalReasonsError	451	Unavailable For Legal Reasons

Server Errors (5xx)

Class	Status	Status Text
InternalServerError	500	Internal Server Error
NotImplementedError	501	Not Implemented
BadGatewayError	502	Bad Gateway
ServiceUnavailableError	503	Service Unavailable
GatewayTimeoutError	504	Gateway Timeout
HttpVersionNotSupportedError	505	HTTP Version Not Supported
VariantAlsoNegotiatesError	506	Variant Also Negotiates
InsufficientStorageError	507	Insufficient Storage
LoopDetectedError	508	Loop Detected
NotExtendedError	510	Not Extended
NetworkAuthenticationRequiredError	511	Network Authentication Required

Working with Error Bodies

import { typedFetch, BadRequestError, isHttpError } from '@pbpeterson/typed-fetch';

const { error } = await typedFetch('/api/users');

if (error && isHttpError(error)) {
  // Typed JSON parsing
  const details = await error.json<{ message: string; code: string }>();

  // Other formats (clone first for multiple reads)
  const text = await error.clone().text();
  const blob = await error.clone().blob();
  const buffer = await error.clone().arrayBuffer();

  // Response metadata
  console.log(error.status);                         // 400 (literal)
  console.log(error.statusText);                     // "Bad Request" (literal)
  console.log(error.name);                           // "BadRequestError"
  console.log(error.headers.get('content-type'));     // response header
}

Cloning Errors

Clone an error to read the body in multiple formats:

if (isHttpError(error)) {
  const cloned = error.clone();

  const json = await error.json();
  const text = await cloned.text();
}