ts-strict-error

ts-strict-error is an extremely simple little library that provides some nice ergonomics for creating errors in Typescript that you can ts-pattern against.

Usage

import { createError, None } from "ts-strict-error";

const NetworkError = createStrictError("NetworkError");
const NonOkStatusCode = createStrictError<
  "NonOkStatusCode",
  None,
  { code: number }
>("NonOkStatusCode");

const FetchError = createStrictError<
  "Fetch",
  InstanceType<typeof NetworkError> | InstanceType<typeof NonOkStatusCode>
>("Fetch");

match(new FetchErr({ from: new NonOkStatusCode({ context: { code: 500 } }) }))
  .with({ name: "Fetch", cause: { name: "NetworkError" } }, () => {
    console.log("No network connection available");
  })
  .with({ name: "Fetch", cause: { name: "NonOkStatusCode" } }, ({ cause }) => {
    console.log(`Received non-OK status code: ${cause.context.code}`);
  })
  .exhaustive();