Add missing index parameter to the Array.fromAsync's mapFn (#59837)

Author: Andarist

src/lib/esnext.array.d.ts

@@ -13,5 +13,5 @@ interface ArrayConstructor {
      *      Each return value is awaited before being added to result array.
      * @param thisArg Value of 'this' used when executing mapfn.
      */
-    fromAsync<T, U>(iterableOrArrayLike: AsyncIterable<T> | Iterable<T> | ArrayLike<T>, mapFn: (value: Awaited<T>) => U, thisArg?: any): Promise<Awaited<U>[]>;
+    fromAsync<T, U>(iterableOrArrayLike: AsyncIterable<T> | Iterable<T> | ArrayLike<T>, mapFn: (value: Awaited<T>, index: number) => U, thisArg?: any): Promise<Awaited<U>[]>;
 }

tests/baselines/reference/arrayFromAsync.js

@@ -12,7 +12,7 @@ function * genPromises (n) {
         yield Promise.resolve(i * 2);
     }
 }
-  
+
 const arrLike = {
     0: Promise.resolve(0),
     1: Promise.resolve(2),
@@ -42,7 +42,10 @@ const mapArr3 = await Array.fromAsync([0,2,4,6], v => v ** 2);
 const err = new Error;
 const badIterable = { [Symbol.iterator] () { throw err; } };
 // This returns a promise that will reject with `err`.
-const badArray = await Array.fromAsync(badIterable);
+const badArray = await Array.fromAsync(badIterable);
+
+const withIndexResult = await Array.fromAsync(["a", "b"], (str, index) => ({ index, str }));
+
 
 //// [arrayFromAsync.js]
 async function* asyncGen(n) {
@@ -79,4 +82,5 @@ const err = new Error;
 const badIterable = { [Symbol.iterator]() { throw err; } };
 // This returns a promise that will reject with `err`.
 const badArray = await Array.fromAsync(badIterable);
+const withIndexResult = await Array.fromAsync(["a", "b"], (str, index) => ({ index, str }));
 export {};

tests/baselines/reference/arrayFromAsync.symbols

@@ -33,7 +33,7 @@ function * genPromises (n) {
 >i : Symbol(i, Decl(arrayFromAsync.ts, 7, 12))
     }
 }
-  
+
 const arrLike = {
 >arrLike : Symbol(arrLike, Decl(arrayFromAsync.ts, 12, 5))
 
@@ -185,3 +185,13 @@ const badArray = await Array.fromAsync(badIterable);
 >fromAsync : Symbol(ArrayConstructor.fromAsync, Decl(lib.esnext.array.d.ts, --, --), Decl(lib.esnext.array.d.ts, --, --))
 >badIterable : Symbol(badIterable, Decl(arrayFromAsync.ts, 39, 5))
 
+const withIndexResult = await Array.fromAsync(["a", "b"], (str, index) => ({ index, str }));
+>withIndexResult : Symbol(withIndexResult, Decl(arrayFromAsync.ts, 43, 5))
+>Array.fromAsync : Symbol(ArrayConstructor.fromAsync, Decl(lib.esnext.array.d.ts, --, --), Decl(lib.esnext.array.d.ts, --, --))
+>Array : Symbol(Array, Decl(lib.es5.d.ts, --, --), Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.core.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --) ... and 4 more)
+>fromAsync : Symbol(ArrayConstructor.fromAsync, Decl(lib.esnext.array.d.ts, --, --), Decl(lib.esnext.array.d.ts, --, --))
+>str : Symbol(str, Decl(arrayFromAsync.ts, 43, 59))
+>index : Symbol(index, Decl(arrayFromAsync.ts, 43, 63))
+>index : Symbol(index, Decl(arrayFromAsync.ts, 43, 76))
+>str : Symbol(str, Decl(arrayFromAsync.ts, 43, 83))
+