frontend/sync-client/src/utils/create-promise.ts

@@ -1,17 +1,23 @@
+type ResolveFunction<T> = undefined extends T
+	? (value?: T) => unknown
+	: (value: T) => unknown;
+
 /**
  * A type-safe utility function to create a Promise with resolve and reject functions.
  * @returns A tuple containing a Promise, a resolve function, and a reject function.
  */
-export function createPromise<T = unknown>(): [
+export function createPromise<T = unknown | undefined>(): [
 	Promise<T>,
-	(value: T) => unknown,
+	ResolveFunction<T>,
 	(error: unknown) => unknown
 ] {
-	let resolve: undefined | ((resolved: T) => unknown) = undefined;
+	let resolve: undefined | ResolveFunction<T> = undefined;
 	let reject: undefined | ((error: unknown) => unknown) = undefined;
 
 	const creationPromise = new Promise<T>(
-		(resolve_, reject_) => ((resolve = resolve_), (reject = reject_))
+		(resolve_, reject_) => (
+			(resolve = resolve_ as ResolveFunction<T>), (reject = reject_)
+		)
 	);
 
 	// eslint-disable-next-line @typescript-eslint/no-non-null-assertion