Combine types not inferred properly for homogenous ResultAsync list

I have code similar to the following:

result.andThen(value => {
  // ...
  return combine([
    ResultAsync.fromPromise(
      getBalance(senderAddress), // returns Promise<BigNumber>
      (err) => new Error(...),
    ),
    ResultAsync.fromPromise(
      getBalance(receiverAddress), // returns Promise<BigNumber>
      (err) => new Error(...),
    ),
  ]);
}).andThen(([senderBalance, receiverBalance]) => {
  // senderBalance and receiverBalance should both be typed as BigNumber
});

When I try this code, I get type errors:

Argument of type '([senderBalance, receiverBalance]: [any, any]) => ResultAsync<unknown, HandlerError> | ResultAsync<undefined, unknown>' is not assignable to parameter of type '(t: unknown) => Result<unknown, unknown> | ResultAsync<unknown, unknown>'.
  Types of parameters '__0' and 't' are incompatible.
    Type 'unknown' is not assignable to type '[any, any]'.ts(2345)

Am I doing something wrong? If I change the last andThen to the following it works:

.andThen((balances) => {
  const [senderBalance, receiverBalance] = balances as BigNumber[];
  // ...
});

I don’t believe I should have to cast it since the combine should give me the proper result with an array of values.

[supermacro]

This Comment Is Kind Of Irrelevant. Safe To Skip To Next Comment.

The following comment is regarding heterogeneous lists and I later realized that we were talking about homogeneous lists. Keeping this here for context anyways.

---

This is a known issue which I have not had the time to address … #226 provides some (somewhat outdated) context on the problem. This comment summarizes the discussion.

I am open to addressing the issue (given I have time, or someone else is able to address this sooner than me) under a MAJOR change for the package.

---

Anyways, the current way that I work around this “limitation” is to declare lists as const so as to turn them into tuples.

  return combine([
    ResultAsync.fromPromise(
      getBalance(senderAddress), // returns Promise<BigNumber>
      (err) => new Error(...),
    ),
    ResultAsync.fromPromise(
      getBalance(receiverAddress), // returns Promise<BigNumber>
      (err) => new Error(...),
    ),
  ] as const);

Here is another example:

  return combine([
    functionThatReturnsOneResultAsync(arg1),
    functionThatReturnsDifferentResultAsync(arg2),
  ] as const)

Info on “const assertions”:

https://mariusschulz.com/blog/const-assertions-in-literal-expressions-in-typescript

[supermacro]

Closing because of lack of response from @rhlsthrm, feel free to reopen though!