http-sentinel

HTTP Error Handling Library

A TypeScript library that provides a comprehensive set of HTTP error classes and utilities for handling HTTP errors in your applications.

Table of Contents

• Features

• Installation

• Available Error Classes

  • 4xx Client Errors
  • 5xx Server Errors

• API Reference: Core (http-sentinel)

  • Purpose

  • TypeScript Support

  • 1. Main Namespace: Core()

    • 1.1. throw (shortcut to throw HTTP errors)
    • 1.2. collections
    • 1.3. tools
    • 1.4. create

  • 2. Common Examples

  • 3. Notes

---

Features

• Complete set of HTTP error classes (4xx and 5xx status codes)
• Type-safe error handling
• Custom error messages support
• Utility functions for error type checking
• TypeScript support with full type definitions
• Factory function for creating custom HTTP errors

Installation

npm i http-sentinel

Available Error Classes

4xx Client Errors

• BadRequest (400)
• Unauthorized (401)
• PaymentRequired (402)
• Forbidden (403)
• NotFound (404)
• MethodNotAllowed (405)
• NotAcceptable (406)
• ProxyAuthenticationRequired (407)
• RequestTimeout (408)
• Conflict (409)
• Gone (410)
• LengthRequired (411)
• PreconditionFailed (412)
• PayloadTooLarge (413)
• URITooLong (414)
• UnsupportedMediaType (415)
• RangeNotSatisfiable (416)
• ExpectationFailed (417)
• ImATeapot (418)
• MisdirectedRequest (421)
• UnprocessableEntity (422)
• Locked (423)
• FailedDependency (424)
• TooEarly (425)
• UpgradeRequired (426)
• PreconditionRequired (428)
• TooManyRequests (429)
• RequestHeaderFieldsTooLarge (431)
• UnavailableForLegalReasons (451)

5xx Server Errors

• InternalServer (500)
• NotImplemented (501)
• BadGateway (502)
• ServiceUnavailable (503)
• GatewayTimeout (504)
• HTTPVersionNotSupported (505)
• VariantAlsoNegotiates (506)
• InsufficientStorage (507)
• LoopDetected (508)
• NotExtended (510)
• NetworkAuthenticationRequired (511)

---

API Reference: Core (http-sentinel)

This reference describes the components exposed by Core() in English, in tabular format, with usage examples.

Purpose

Provide a quick guide to develop and handle custom HTTP errors using the object returned by Core().

---

TypeScript Support

The library provides TypeScript type definitions for improved DX and type safety:

• HttpStatusCode: a union type of valid HTTP status codes (e.g., 400 | 401 | 404 | 500 | ...).

• HttpErrorMessage: can be either a plain string or a predefined set of messages provided by http-sentinel.

  • Predefined messages cover common HTTP error scenarios.
  • Allows any other string as a custom message.

• ExpectedError: a union type of all standard error class instances provided by http-sentinel.

  • Represents the complete set of recognized error instances.
  • Useful for narrowing catch blocks and ensuring type safety when handling known errors.

---

1. Main Namespace: stn

Returns an object with four main groups: throw, collections, tools, and create.

1.1. throw (shortcut to throw HTTP errors)

Error Name	Optional Parameter	What it does	Example
BadRequest	message?: HttpErrorMessage	Throws a 400 error.	stn.throw.BadRequest('Missing parameters')
...	...	...	...
UnknownError	message?: HttpErrorMessage	Throws a generic uncategorized error.	stn.throw.UnknownError()

---

1.2. collections

Property	Description	Example Usage
BadRequest, Unauthorized, ..., UnknownError	Specific HTTP error classes.	if (error instanceof stn.collections.NotFound) { ... }

---

1.3. tools

Function	Parameters	Returns	Description	Example
resolveHttpError	statusCode: number	Throws	Maps an HTTP numeric code to its corresponding error and throws it.	stn.tools.resolveHttpError(404)
compare	caughtError: unknown, target: ErrorConstructor	boolean	Checks if the caught error matches a specific HTTP error class.	stn.tools.compare(err, stn.collections.BadRequest)
matches	err: unknown	boolean	Detects if the error was created by http-sentinel's base structure.	if (stn.tools.matches(err)) { /* handle */ }

---

1.4. create

Property	Description	Example
customError	Creates a custom or extended HTTP error based on http-sentinel's foundations. Status code is optional.	stn.create.customError('MyError', 'customMessage') or stn.create.customError('MyError', 'customMessage', 422)

---

2. Common Examples

2.1. Resolve and throw by code

import { stn } from "http-sentinel"

const status = 403
try {
  stn.tools.resolveHttpError(status);
} catch (e) {
  if (stn.tools.matches(e)) {
    // uniform handling
  }
}

2.2. Compare caught errors

import { stn } from "http-sentinel"

try {
  stn.throw.NotFound('User not found');
} catch (err) {
  if (stn.tools.compare(err, stn.collections.NotFound)) {
    console.log('It is an explicit 404');
  }
}

2.3. Define a custom error

import { stn } from "http-sentinel"

const MyError = stn.create.customError('MyError', 'Something strange happened');
throw new MyError('Custom thrown');

---

3. Notes

• Functions in throw always throw the error; they do not return a value. If you need to handle it without breaking the flow, wrap it in try/catch.
• collections provides the class references for instanceof checks and for passing to compare.
• matches is useful to filter out errors that are not part of the http-sentinel ecosystem and avoid false positives.
• customError allows extension with additional metadata for traceability. The status code argument is optional.
• TypeScript's HttpStatusCode, HttpErrorMessage, and ExpectedError types provide strong typing for status codes, messages, and known error instances.

4. Request

This library also includes a function to make HTTP requests to an API, automatically integrating error handling via http-sentinel utilities. It provides a simple and fast way to fetch data and manage any failures. It uses the same signature (parameters and options) as the native fetch function.

import { request } from "http-sentinel";

interface User {
  id: number;
  name: string;
  role: string;
}

// GET
const { success, data, error } = await request.get<User>({
  url: "/api/users/1",
  timeout: 5000
});

if (success && data) {
  console.log(data.name);       // Typed as User
  console.log(data.role);       
} else {
  // Manejo de errores estandarizado
  console.error("Error:", error?.message);
  console.error("Tipo:", error?.name);
  console.error("Código HTTP:", error?.statusCode);
}

Here’s an example of a POST request using the same http-sentinel API:

import { request } from "http-sentinel";

interface User {
  id: number;
  name: string;
  role: string;
}

interface CreateUserPayload {
  name: string;
  role: string;
}

const newUser: CreateUserPayload = {
  name: "Alice",
  role: "admin",
};


// POST request
const { success, data, error } = await request.post<User>(
  {
    url: "/api/users",
    options: { body: JSON.stringify(newUser) },
    timeout: 5000
  }
);

if (success && data) {
  console.log("Created user ID:", data.id);  // Typed as User
  console.log("Name:", data.name);
  console.log("Role:", data.role);
} else {
  // Standardized error handling
  console.error("Error:", error?.message);
  console.error("Type:", error?.name);
  console.error("HTTP Status Code:", error?.statusCode);
}

Test Coverage

To run your tests in CI mode and generate a coverage report, use:

npm run test:ci