typescript match, result, option

index.ts

import { Err, err, Ok, ok, type Result } from "neverthrow";
import { none, Option, some } from "ts-option";
import { match, P } from "ts-pattern";

type Foo = {
  str: string;
  some: Option<string>;
  none: Option<string>;
};

const make = (val: boolean): Result<Foo, Error> => {
  if (val) {
    return ok({
      str: "hello",
      some: some("foo"),
      none: none,
    });
  } else {
    return err(new Error("failed"));
  }
};

const okRes = make(true);
const errRes = make(false);

match(okRes)
  .with(P.instanceOf(Ok), (foo) => console.log("ok!", foo))
  .with(P.instanceOf(Err), (err) => console.error("error...", err))
  .exhaustive();

match(errRes)
  .with(P.instanceOf(Ok), (foo) => console.log("ok!", foo))
  .with(P.instanceOf(Err), (err) => console.error("error...", err))
  .exhaustive();