Fix asyncFn type

src/fn.ts

@@ -1,32 +1,21 @@
 import type {Result} from "./result"
 import {PromiseResult} from "./promise_result"
-import type {Err, InferErr, InferOk, Ok} from "./internal"
+import type {InferErr, InferOk} from "./internal"
 
 export function fn<A extends any[], R extends Result<any, any>>(
 	f: (...args: A) => R,
 ): (...args: A) => Result<InferOk<R>, InferErr<R>> {
 	return f
 }
 
-export function asyncFn<A extends any[], T>(
-	f: (...args: A) => Promise<Ok<T>>,
-): (...args: A) => PromiseResult<T, never>
-export function asyncFn<A extends any[], E>(
-	f: (...args: A) => Promise<Err<E>>,
-): (...args: A) => PromiseResult<never, E>
-export function asyncFn<A extends any[], T, E>(
-	f: (...args: A) => Promise<Ok<T> | Err<E>>,
-): (...args: A) => PromiseResult<T, E>
-export function asyncFn<A extends any[], T, E>(
-	f: (...args: A) => Promise<Result<T, E>>,
-): (...args: A) => PromiseResult<T, E>
-export function asyncFn<A extends any[], T, E>(
-	f: (...args: A) => PromiseResult<T, E>,
-): (...args: A) => PromiseResult<T, E>
-export function asyncFn<A extends any[], T, E>(
-	f: (...args: A) => Promise<Ok<T> | Err<E> | Result<T, E>> | PromiseResult<T, E>,
-): (...args: A) => PromiseResult<T, E> {
-	return function (...args: A) {
-		return new PromiseResult<T, E>(f(...args))
+export function asyncFn<A extends any[], R extends PromiseResult<any, any>>(
+	f: (...args: A) => R,
+): (...args: A) => PromiseResult<InferOk<Awaited<R>>, InferErr<Awaited<R>>>
+export function asyncFn<A extends any[], R extends Promise<Result<any, any>>>(
+	f: (...args: A) => R,
+): (...args: A) => PromiseResult<InferOk<Awaited<R>>, InferErr<Awaited<R>>>
+export function asyncFn(f: any): any {
+	return function (...args: any[]) {
+		return new PromiseResult(f(...args))
 	}
 }

test/fn.test.ts

@@ -116,11 +116,19 @@ describe.concurrent("asyncFn", () => {
 				if (Math.random() > 0.5) {
 					return Ok(1)
 				}
+				if (Math.random() > 0.5) {
+					return Ok("foo")
+				}
+				if (Math.random() > 0.5) {
+					return Err(1)
+				}
 				return Err("error")
 			}
 			const wrapped = asyncFn(f)
 			expectTypeOf(wrapped).parameter(0).toBeNumber()
-			expectTypeOf(wrapped).returns.toEqualTypeOf<PromiseResult<number, string>>()
+			expectTypeOf(wrapped).returns.toEqualTypeOf<
+				PromiseResult<number | string, number | string>
+			>()
 		})
 
 		it("returns correct type with function returning Promise<Ok>", () => {