@gautam-taab/domain-errors

Typed errors shared across TAAB services. Each error carries an HTTP status and serializes to an RFC 7807 Problem Details object.

Install

npm install @gautam-taab/domain-errors

Usage

import { UserNotFoundError, formatDomainError } from "@gautam-taab/domain-errors";

throw new UserNotFoundError({ detail: "User 1234 was not found", instance: "/users/1234" });

// In an error handler:
const problem = formatDomainError(err, req.originalUrl);
res.status(problem.status).json(problem);
// { type: "not-found", title: "Not Found", status: 404, detail: "User 1234 was not found",
//   instance: "/users/1234", code: "USER_NOT_FOUND" }

Works with both import and require.

Errors

• Core errors set the HTTP status, type and title: BadRequestError (400), UnauthorizedError (401), ForbiddenError (403), NotFoundError (404), ConflictError (409), UnprocessableEntityError (422), TooManyRequestsError (429), InternalServerError (500), BadGatewayError (502), ServiceUnavailableError (503), GatewayTimeoutError (504).
• Domain errors extend a core error and add a default detail and an UPPER_SNAKE code, for example UserNotFoundError (USER_NOT_FOUND) or InsufficientBalanceError (INSUFFICIENT_BALANCE). All are exported from the package root.

Every constructor takes optional ErrorOptions:

| Option | Effect | | :-- | :-- | | detail | Replaces the default detail. Also becomes error.message. | | code | Replaces the default code. | | instance | URI of the failing request or resource. | | extensions | Extra fields, merged into the top level of the Problem Details object. |

status, type and title cannot be overridden: they come from the core error.

formatDomainError(error, defaultInstance?) returns the Problem Details object. Any error that is not a domain error becomes a 500 with its message as detail.

Development

npm ci
npm test
npm run build   # cleans dist/, then compiles
npm publish     # builds and runs the tests first