Create errors.ts

Author: BeauBouchard

src/middleware/errors.ts

@@ -0,0 +1,274 @@
+import { NextFunction, Request, Response } from "express";
+
+/**
+ * Philosophically don't look to adopt the perfect response shape,
+ * instead look to adopt the one you like and then adapt it to your needs.
+ * Errors, and adding RESTful information is a good ideal.
+ * statusCode, error message, and stack trace or error payloads are enough for most cases.
+ */
+class HttpException extends Error {
+  public readonly statusCode: number;
+  public message: string;
+  public name: string;
+  public readonly data?: string;
+
+  /**
+   * A generic Exception class for HTTP responses
+   * @param statusCode {number} - HTTP status code
+   * @param message {string} - Error message
+   * @param name {string} - Error data
+   * @param data {string} - Optional error payload
+   */
+  constructor(status: number, message: string, name: string, data?: string) {
+    super(message);
+    this.statusCode = status;
+    this.message = message;
+    this.name = name;
+    if (typeof data !== "undefined") {
+      this.data = data;
+    }
+  }
+
+  /**
+   *
+   * @param message {string} - additional messages to be added to the error message
+   */
+  appendMessage(message: string) {
+    this.message += ` ${message}`;
+  }
+}
+
+const exceptions = [
+  new HttpException(
+    400,
+    "The request syntax is malformed or invalid",
+    "BadRequest"
+  ),
+  new HttpException(
+    401,
+    "You are not authorized, the client must authenticate itself to get the requested response.",
+    "Unauthorized"
+  ),
+  new HttpException(402, "Payme", "PaymentRequired"),
+  new HttpException(
+    403,
+    "You are not authorized, we know which user you are, but the item you requested is not allowed to be given to you",
+    "Forbidden"
+  ),
+  new HttpException(
+    404,
+    "The item you are looking for is not found",
+    "NotFound"
+  ),
+  new HttpException(
+    405,
+    "The method you are using is not allowed",
+    "MethodNotAllowed"
+  ),
+  new HttpException(
+    406,
+    "The requested resource is not available in the format you requested",
+    "NotAcceptable"
+  ),
+  new HttpException(407, "Proxy Authentication Required", "ProxyAuthRequired"),
+  new HttpException(
+    408,
+    "The server timed out waiting for the request",
+    "RequestTimeout"
+  ),
+  new HttpException(
+    409,
+    "The request could not be processed because of conflict in the request",
+    "Conflict"
+  ),
+  new HttpException(
+    410,
+    "The requested resource is no longer available",
+    "Gone"
+  ),
+  new HttpException(
+    411,
+    "The request did not specify the length of its content, which is required by the requested resource",
+    "LengthRequired"
+  ),
+  new HttpException(
+    412,
+    "The server does not meet one of the preconditions that the requester put on the request",
+    "PreconditionFailed"
+  ),
+  new HttpException(
+    413,
+    "The request is larger than the server is willing or able to process",
+    "RequestEntityTooLarge"
+  ),
+  new HttpException(
+    414,
+    "The URI provided was too long for the server to process",
+    "RequestURITooLong"
+  ),
+  new HttpException(
+    415,
+    "The request entity has a media type which the server or resource does not support",
+    "UnsupportedMediaType"
+  ),
+  new HttpException(
+    416,
+    "The client has asked for a portion of the file, but the server cannot supply that portion",
+    "RequestRangeNotSatisfiable"
+  ),
+  new HttpException(
+    417,
+    "The server cannot meet the requirements of the Expect request-header field",
+    "ExpectationFailed"
+  ),
+  new HttpException(
+    418,
+    "The request was directed at a server that is not able to produce a response",
+    "ImATeapot"
+  ),
+  new HttpException(
+    421,
+    "The request was directed at a server that is not able to produce a response",
+    "ImATeapot"
+  ),
+  new HttpException(
+    422,
+    "The request was well-formed but was unable to be followed due to semantic errors",
+    "UnprocessableEntity"
+  ),
+  new HttpException(
+    423,
+    "The resource that is being accessed is locked",
+    "Locked"
+  ),
+  new HttpException(
+    424,
+    "The request failed due to failure of a previous request",
+    "FailedDependency"
+  ),
+  new HttpException(
+    426,
+    "The client should switch to a different protocol",
+    "UpgradeRequired"
+  ),
+  new HttpException(
+    428,
+    "The origin server requires the request to be conditional",
+    "PreconditionRequired"
+  ),
+  new HttpException(
+    429,
+    "The user has sent too many requests in a given amount of time. Intended for use with rate limiting schemes",
+    "TooManyRequests"
+  ),
+  new HttpException(
+    431,
+    "The server is unwilling to process the request because its header fields are too large",
+    "RequestHeaderFieldsTooLarge"
+  ),
+  new HttpException(
+    451,
+    "The server is denying access to the resource as a consequence of a legal demand",
+    "UnavailableForLegalReasons"
+  ),
+  new HttpException(
+    500,
+    "The server has encountered a situation it doesn't know how to handle",
+    "InternalServerError"
+  ),
+  new HttpException(
+    501,
+    "The request method is not supported by the server and cannot be handled",
+    "NotImplemented"
+  ),
+  new HttpException(
+    502,
+    "The server received an invalid response from a server it consulted when acting as a proxy or gateway",
+    "BadGateway"
+  ),
+  new HttpException(
+    503,
+    "The server is currently unavailable (because it is overloaded or down for maintenance)",
+    "ServiceUnavailable"
+  ),
+  new HttpException(
+    504,
+    "The server was acting as a gateway or proxy and did not receive a timely response from the upstream server",
+    "GatewayTimeout"
+  ),
+  new HttpException(
+    505,
+    "The server does not support the HTTP protocol version used in the request",
+    "HTTPVersionNotSupported"
+  ),
+  new HttpException(
+    506,
+    "Transparent content negotiation for the request results in a circular reference",
+    "VariantAlsoNegotiates"
+  ),
+  new HttpException(
+    507,
+    "The server is unable to store the representation needed to complete the request",
+    "InsufficientStorage"
+  ),
+  new HttpException(
+    508,
+    "The server detected an infinite loop while processing the request",
+    "LoopDetected"
+  ),
+  new HttpException(
+    510,
+    "Further extensions to the request are required for the server to fulfill it",
+    "NotExtended"
+  ),
+  new HttpException(
+    511,
+    "The client needs to authenticate to gain network access",
+    "NetworkAuthenticationRequired"
+  ),
+];
+
+/**
+ *
+ * @param statusCode {number} - the status code of the error
+ * @returns {HttpException} - the exception
+ */
+function getExceptionByStatusCode(statusCode: number): HttpException {
+  const exception = exceptions.find((e) => e.statusCode === statusCode);
+  if (exception) {
+    return exception;
+  }
+  return new HttpException(
+    statusCode,
+    `Unknown status code ${statusCode}`,
+    "Unknown"
+  );
+}
+
+const code = getExceptionByStatusCode;
+
+/**
+ *
+ * @param {Request} request - Express request object
+ * @param {Response} response - Express response object
+ * @param {NextFunction} next - Express next function
+ */
+function errorMiddleware(
+  error: Error | HttpException,
+  request: Request,
+  response: Response,
+  next: NextFunction
+) {
+  if (response.headersSent) {
+    return next(error);
+  }
+  if (error instanceof HttpException) {
+    response.status(error.statusCode);
+    response.send(error);
+  } else {
+    response.status(500);
+    response.send(code(500));
+  }
+}
+
+export { errorMiddleware, exceptions, HttpException, code };