From a9b6f1be38f1c96655cff7298e45eae8ca1bdf54 Mon Sep 17 00:00:00 2001
From: regevbr <regevbr@gmail.com>
Date: Fri, 22 Nov 2019 00:51:43 +0200
Subject: [PATCH] Fix #70 Add DLQ rebumitter tool

---
 src/resubmitter.ts | 76 +++++++++++++++++++---------------------------
 1 file changed, 32 insertions(+), 44 deletions(-)

diff --git a/src/resubmitter.ts b/src/resubmitter.ts
index 0d74de1..6238869 100644
--- a/src/resubmitter.ts
+++ b/src/resubmitter.ts
@@ -4,10 +4,6 @@ import {SQS_MAX_RECEIVE_BATCH, Squiss} from './Squiss';
 import {IMessageToSend, ResubmitterConfig} from './Types';
 import {Message} from './Message';
 
-interface MessageContext {
-    readonly message: Message;
-}
-
 const DEFAULT_SQUISS_OPTS = {
     receiveAttributes: ['All'],
     receiveSqsAttributes: ['All'],
@@ -43,63 +39,55 @@ export class Resubmitter {
         return this.squissFrom.getManualBatch(numberOfMessageToRead);
     }
 
-    private _sendMessage(messageToSend: IMessageToSend, context: MessageContext) {
-        return this.squissTo.sendMessage(messageToSend, undefined, context.message.attributes);
+    private _sendMessage(messageToSend: IMessageToSend, message: Message) {
+        return this.squissTo.sendMessage(messageToSend, undefined, message.attributes);
     }
 
-    private _handleMessage(context: MessageContext): Promise<any> {
-        return Promise.resolve()
-            .then(() => {
-                let body = context.message.body;
-                if (this.config.customMutator) {
-                    body = this.config.customMutator(body);
-                }
-                return this._sendMessage(body, context);
-            });
+    private _changeMessageVisibility(message: Message) {
+        return message.changeVisibility(this.config.releaseTimeoutSeconds);
+    }
+
+    private _handleMessage(message: Message): Promise<void> {
+        return Promise.resolve().then(() => {
+            console.log(`${++this.numHandledMessages} messages handled`);
+            const location = message.raw.MessageId ?? '';
+            if (this.numHandledMessages > this.config.limit || this.handledMessages.has(location)) {
+                return this._changeMessageVisibility(message);
+            }
+            this.handledMessages.add(location);
+            let body = message.body;
+            if (this.config.customMutator) {
+                body = this.config.customMutator(body);
+            }
+            return this._sendMessage(body, message)
+                .then(() => {
+                    return message.del();
+                })
+                .catch((err) => {
+                    return this._changeMessageVisibility(message)
+                        .then(() => {
+                            return Promise.reject(err);
+                        });
+                });
+        });
     }
 
     private _iteration(): Promise<void> {
         if (this.numHandledMessages >= this.config.limit || this.config.limit <= 0) {
             return Promise.resolve();
         }
-        const remaining = Math.max(this.config.limit - this.numHandledMessages, 0);
-        const numberOfMessageToRead = Math.min(SQS_MAX_RECEIVE_BATCH, remaining);
+        const numberOfMessageToRead =
+            Math.min(SQS_MAX_RECEIVE_BATCH, Math.max(this.config.limit - this.numHandledMessages, 0));
         if (numberOfMessageToRead <= 0) {
             return Promise.resolve();
         }
         return this._readMessages(numberOfMessageToRead)
             .then((messages) => {
                 if (!messages.length) {
-                    // Make sure the iteration stops
                     this.numHandledMessages = this.config.limit;
                     return Promise.resolve();
                 }
-                const promises = messages.map((message) => {
-                    const msgContext: MessageContext = {
-                        message,
-                    };
-                    return Promise.resolve().then(() => {
-                        console.log(`${++this.numHandledMessages} messages handled`);
-                        if (this.numHandledMessages > this.config.limit) {
-                            return message.changeVisibility(this.config.releaseTimeoutSeconds);
-                        }
-                        const location = message.raw.MessageId ?? '';
-                        if (this.handledMessages.has(location)) {
-                            return message.changeVisibility(this.config.releaseTimeoutSeconds);
-                        }
-                        this.handledMessages.add(location);
-                        return this._handleMessage(msgContext)
-                            .then(() => {
-                                return message.del();
-                            })
-                            .catch((err) => {
-                                return message.changeVisibility(this.config.releaseTimeoutSeconds)
-                                    .then(() => {
-                                        return Promise.reject(err);
-                                    });
-                            });
-                    });
-                });
+                const promises = messages.map(this._handleMessage.bind(this));
                 return Promise.all(promises).then(() => {
                     return Promise.resolve();
                 });