remix: V2 Bug: New `JsonifyObject` type causing union type issues with Typescript

What version of Remix are you using?

2.0.1

Are all your remix dependencies & dev-dependencies using the same version?

• Yes

Steps to Reproduce

If you have a loader or action function which can return different object structures the new JsonifyObject abstraction type appears to not be properly understood by typescript meaning the code below cannot compile let alone run, even though it was valid in 1.19.* - and theoretically should be valid code.

app/routes/test.tsx

import type { ActionFunctionArgs } from "@remix-run/node";
import { useActionData } from "@remix-run/react";
import { json } from "@remix-run/node";

export async function action (args: ActionFunctionArgs) {
	const formData = await args.request.formData();
	const action = formData.get("action")?.toString() || "";

	switch (action) {
		case "a": return json({a: true});
		case "b": return json({b: true});
		default: throw new Response("Unexpected form action", {
			statusText: "Bad request",
			status: 400
		});
	}
};

export default function Index() {
	const actionData = useActionData<typeof action>();
	if (actionData?.a) console.log("It was a");
	if (actionData?.b) console.log("It was B");

	return <div>Hi</div>;
}

Expected Behavior

Typescript should correctly identify the type as effectively

const actionData: { a: boolean } | { b: boolean } | undefined;

And it indeeed identifying the type to be something close to this:

const actionData: JsonifyObject<{
    a: boolean;
}> | JsonifyObject<{
    b: boolean;
}> | undefined

Actual Behavior

Line 20: Property 'a' does not exist on type 'JsonifyObject<{ a: boolean; }> | JsonifyObject<{ b: boolean; }>'.
  Property 'a' does not exist on type 'JsonifyObject<{ b: boolean; }>'.ts(2339)

Line 21: Property 'b' does not exist on type 'JsonifyObject<{ a: boolean; }> | JsonifyObject<{ b: boolean; }>'.
  Property 'b' does not exist on type 'JsonifyObject<{ a: boolean; }>'.ts(2339