add comments to async helpers

Author: yaacovCR

src/jsutils/after.ts

@@ -1,6 +1,14 @@
 import { isPromise } from './isPromise.js';
 import type { PromiseOrValue } from './PromiseOrValue.js';
 
+/**
+ * Async Helper Function that avoides `.then()`
+ *
+ * It is faster to await a promise prior to returning it from an async function
+ * than to return a promise with `.then()`.
+ *
+ * see: https://github.com/tc39/proposal-faster-promise-adoption
+ */
 export async function after<T, R>(
   promise: Promise<T>,
   onFulfilled: (value: T) => PromiseOrValue<R>,

src/jsutils/catchAfter.ts

@@ -1,3 +1,11 @@
+/**
+ * Async Helper Function that avoides `.then()`
+ *
+ * It is faster to await a promise prior to returning it from an async function
+ * than to return a promise with `.then()`.
+ *
+ * see: https://github.com/tc39/proposal-faster-promise-adoption
+ */
 export async function catchAfter<T, U>(
   promise: Promise<T>,
   onError: (error: any) => U,

src/jsutils/tryAfter.ts

@@ -1,3 +1,11 @@
+/**
+ * Async Helper Function that avoides `.then()`
+ *
+ * It is faster to await a promise prior to returning it from an async function
+ * than to return a promise with `.then()`.
+ *
+ * see: https://github.com/tc39/proposal-faster-promise-adoption
+ */
 export async function tryAfter<T, U, R = T>(
   promise: Promise<T>,
   onFulfilled: (value: T) => R,