orElse returns the wrong type when the callback changes the ok type

[lantw44]

Result is broken. It doesn't track ok type changes.

import { Result, ok, err } from 'neverthrow';

const a: Result<number, number> = err(1);
const b: Result<number, number> = a.orElse(() => ok('A'));
console.log(b);

$ npx tsc
$ node main.js
Ok { value: 'A' }

The ok type of b is string, but TypeScript thinks it is number.

ResultAsync is fine. It rejects ok type changes.

import { ResultAsync, okAsync, errAsync } from 'neverthrow';

const a: ResultAsync<number, number> = errAsync(1);
const b: ResultAsync<number, number> = a.orElse(() => okAsync('A'));
b.then((r) => console.log(r));

$ npx tsc
main.ts:4:7 - error TS2322: Type 'ResultAsync<number, unknown>' is not assignable to type 'ResultAsync<number, number>'.
  Type 'unknown' is not assignable to type 'number'.

4 const b: ResultAsync<number, number> = a.orElse(() => okAsync('A'));
        ~

main.ts:4:55 - error TS2769: No overload matches this call.
  Overload 1 of 3, '(f: (e: number) => Result<number, unknown>): ResultAsync<number, unknown>', gave the following error.
    Type 'ResultAsync<string, never>' is not assignable to type 'Result<number, unknown>'.
      Type 'ResultAsync<string, never>' is missing the following properties from type 'Err<number, unknown>': error, isOk, isErr, asyncAndThen, and 3 more.
  Overload 2 of 3, '(f: (e: number) => ResultAsync<number, unknown>): ResultAsync<number, unknown>', gave the following error.
    Type 'ResultAsync<string, never>' is not assignable to type 'ResultAsync<number, unknown>'.
      Type 'string' is not assignable to type 'number'.
  Overload 3 of 3, '(f: (e: number) => Result<number, never> | ResultAsync<number, never>): ResultAsync<number, never>', gave the following error.
    Type 'ResultAsync<string, never>' is not assignable to type 'Result<number, never> | ResultAsync<number, never>'.
      Type 'ResultAsync<string, never>' is not assignable to type 'ResultAsync<number, never>'.
        Type 'string' is not assignable to type 'number'.

4 const b: ResultAsync<number, number> = a.orElse(() => okAsync('A'));
                                                        ~~~~~~~~~~~~

  node_modules/neverthrow/dist/index.d.ts:19:45
    19     orElse<R extends Result<T, unknown>>(f: (e: E) => R): ResultAsync<T, InferErrTypes<R>>;
                                                   ~~~~~~~~~~~
    The expected type comes from the return type of this signature.
  node_modules/neverthrow/dist/index.d.ts:20:50
    20     orElse<R extends ResultAsync<T, unknown>>(f: (e: E) => R): ResultAsync<T, InferAsyncErrTypes<R>>;
                                                        ~~~~~~~~~~~
    The expected type comes from the return type of this signature.
  node_modules/neverthrow/dist/index.d.ts:21:18
    21     orElse<A>(f: (e: E) => Result<T, A> | ResultAsync<T, A>): ResultAsync<T, A>;
                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    The expected type comes from the return type of this signature.


Found 2 errors in the same file, starting at: main.ts:4

[Chuckytuh]

This seems related with #411