defineErrorMap

defineErrorMap captures an object of error codes with their literal types preserved, so you declare a set of errors once and pass it to a procedure's errors option, reusing it across the procedures and middleware that share those codes. It returns the map unchanged. Its only job is to infer precise types.

Parameters

defineErrorMap(map)

map

An object keyed by error code: your own code (e.g. POST_NOT_FOUND) or a common HTTP code you want to override. Each value is an ErrorDefinition.

Common codes

Keys may be any string, or one of the built-in HTTP codes below. Listing a common code overrides its default status/message. Every common code is throwable from a handler whether or not you list it.

Returns

The same object, typed as const. Assign it to a constant and pass it to a procedure's errors option, and derive its type with typeof when you need to refer to it. At runtime Kizlo turns it into the callable errors map your handler receives (see createThrowableErrorMap).

Examples

Define a map once, including a typed data payload and an override of a built-in error's copy:

import { defineErrorMap } from "kizlo"
import { z } from "zod"

export const POST_ERRORS = defineErrorMap({
  POST_NOT_FOUND: { status: 404, message: "Post not found" },
  FORBIDDEN: { message: "You can't edit this post" }, // override a common error's message
  POST_RATE_LIMITED: { status: 429, data: z.object({ retryAfter: z.number() }) }, // typed payload
})

Pass it to every procedure that shares those codes:

createProcedure(
  { scope: "api", method: "GET", path: "/posts/{id}", /* …schemas… */ errors: POST_ERRORS },
  async ({ errors }) => {
    throw errors.POST_NOT_FOUND()
    // throw errors.POST_RATE_LIMITED({ data: { retryAfter: 30 } }) // data is required and typed
  },
)