From 12a412a3cee8ad4205705894d5d5c54bb39a5856 Mon Sep 17 00:00:00 2001
From: Marin Petrunic <marin.petrunic@gmail.com>
Date: Mon, 30 Jan 2023 18:13:36 +0100
Subject: [PATCH] feat: remove async library

---
 package-lock.json                      |  2 -
 packages/util/package.json             |  1 -
 packages/util/src/asyncEventEmitter.ts | 55 +++++++++++++++-----------
 3 files changed, 32 insertions(+), 26 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index 55f680ca5d..fa3be89ddf 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -18275,7 +18275,6 @@
       "dependencies": {
         "@chainsafe/ssz": "^0.10.0",
         "@ethereumjs/rlp": "^4.0.0",
-        "async": "^3.2.4",
         "ethereum-cryptography": "^1.1.2"
       },
       "devDependencies": {
@@ -19880,7 +19879,6 @@
         "@ethereumjs/rlp": "^4.0.0",
         "@types/bn.js": "^5.1.0",
         "@types/secp256k1": "^4.0.1",
-        "async": "^3.2.4",
         "ethereum-cryptography": "^1.1.2"
       }
     },
diff --git a/packages/util/package.json b/packages/util/package.json
index 8bae0f9b18..83404eca89 100644
--- a/packages/util/package.json
+++ b/packages/util/package.json
@@ -85,7 +85,6 @@
   "dependencies": {
     "@chainsafe/ssz": "^0.10.0",
     "@ethereumjs/rlp": "^4.0.0",
-    "async": "^3.2.4",
     "ethereum-cryptography": "^1.1.2"
   },
   "devDependencies": {
diff --git a/packages/util/src/asyncEventEmitter.ts b/packages/util/src/asyncEventEmitter.ts
index 71db01b1f0..7085b0a672 100644
--- a/packages/util/src/asyncEventEmitter.ts
+++ b/packages/util/src/asyncEventEmitter.ts
@@ -7,7 +7,6 @@
  * https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/async-eventemitter
  */
 
-import { eachSeries } from 'async'
 import { EventEmitter } from 'events'
 type AsyncListener<T, R> =
   | ((data: T, callback?: (result?: R) => void) => Promise<R>)
@@ -16,6 +15,37 @@ export interface EventMap {
   [event: string]: AsyncListener<any, any>
 }
 
+async function runInSeries(
+  context: any,
+  tasks: Array<(data: unknown, callback?: (error?: Error) => void) => void>,
+  data: unknown
+): Promise<void> {
+  let error: Error | undefined
+  for await (const task of tasks) {
+    try {
+      if (task.length < 2) {
+        //sync
+        task.call(context, data)
+      } else {
+        await new Promise<void>((resolve, reject) => {
+          task.call(context, data, (error) => {
+            if (error) {
+              reject(error)
+            } else {
+              resolve()
+            }
+          })
+        })
+      }
+    } catch (e: unknown) {
+      error = e as Error
+    }
+  }
+  if (error) {
+    throw error
+  }
+}
+
 export class AsyncEventEmitter<T extends EventMap> extends EventEmitter {
   emit<E extends keyof T>(event: E & string, ...args: Parameters<T[E]>) {
     let [data, callback] = args
@@ -41,28 +71,7 @@ export class AsyncEventEmitter<T extends EventMap> extends EventEmitter {
 
     // A single listener is just a function not an array...
     listeners = Array.isArray(listeners) ? listeners : [listeners]
-
-    eachSeries(
-      listeners.slice(),
-      function (fn: any, next) {
-        let err
-
-        // Support synchronous functions
-        if (fn.length < 2) {
-          try {
-            fn.call(self, data)
-          } catch (e: any) {
-            err = e
-          }
-
-          return next(err)
-        }
-
-        // Async
-        fn.call(self, data, next)
-      },
-      callback
-    )
+    runInSeries(self, listeners.slice(), data).then(callback).catch(callback)
 
     return self.listenerCount(event) > 0
   }