From cc3d0252c9b428d576407d9e5e58f53a0d05406d Mon Sep 17 00:00:00 2001
From: Molly Draven <drazi@duck.com>
Date: Fri, 27 Sep 2024 21:44:56 -0400
Subject: [PATCH] refactor: migrate socketErrorHandler to separate module

---
 packages/gateway/src/index.ts                 | 45 +------------------
 .../gateway/src/socketErrorHandler.test.ts    | 38 ++++++++++++++++
 packages/gateway/src/socketErrorHandler.ts    | 30 +++++++++++++
 3 files changed, 69 insertions(+), 44 deletions(-)
 create mode 100644 packages/gateway/src/socketErrorHandler.test.ts
 create mode 100644 packages/gateway/src/socketErrorHandler.ts

diff --git a/packages/gateway/src/index.ts b/packages/gateway/src/index.ts
index bf2790381..a999b0809 100644
--- a/packages/gateway/src/index.ts
+++ b/packages/gateway/src/index.ts
@@ -29,49 +29,7 @@ import { getGatewayServer } from "./GatewayServer.js";
 import { getPortMessageType, UserStatusManager } from "rusty-motors-nps";
 import { BasePacket } from "rusty-motors-shared-packets";
 import * as Sentry from "@sentry/node";
-
-/**
- * @typedef {object} OnDataHandlerArgs
- * @property {object} args
- * @property {string} args.connectionId The connection id of the socket that
- *                                  received the data.
- * @property {module:packages/shared/RawMessage} args.message The data that was received.
- * @property {module:shared/log.ServerLogger} [args.log=getServerLogger({ name: "gateway" })] The logger to use.
- *                                                                    response
- *                                                                to the
- *                                                           data.
- */
-
-/**
- * @typedef {function} OnDataHandler
- * @param {OnDataHandlerArgs} args The arguments for the handler.
- * @returns {ServiceResponse} The
- *                                                                     response
- *                                                                  to the
- *                                                            data.
- */
-
-/**
- * Handle socket errors
- */
-export function socketErrorHandler({
-	connectionId,
-	error,
-	log = getServerLogger({
-		name: "socketErrorHandler",
-	}),
-}: {
-	connectionId: string;
-	error: NodeJS.ErrnoException;
-	log?: ServerLogger;
-}) {
-	// Handle socket errors
-	if (error.code == "ECONNRESET") {
-		log.debug(`Connection ${connectionId} reset`);
-		return;
-	}
-	throw Error(`Socket error: ${error.message} on connection ${connectionId}`);
-}
+import { socketErrorHandler } from "./socketErrorHandler.js";
 
 /**
  * Handle the end of a socket connection
@@ -179,7 +137,6 @@ export function onSocketConnection({
 	incomingSocket.on(
 		"data",
 		function socketDataHandler(incomingDataAsBuffer: Buffer) {
-			
 			log.trace(
 				`Incoming data on port ${localPort}: ${incomingDataAsBuffer.toString(
 					"hex",
diff --git a/packages/gateway/src/socketErrorHandler.test.ts b/packages/gateway/src/socketErrorHandler.test.ts
new file mode 100644
index 000000000..98c905e50
--- /dev/null
+++ b/packages/gateway/src/socketErrorHandler.test.ts
@@ -0,0 +1,38 @@
+import { describe, it, expect, vi } from "vitest";
+import { socketErrorHandler } from "./socketErrorHandler.js";
+import { type ServerLogger } from "rusty-motors-shared";
+
+describe("socketErrorHandler", () => {
+
+	it("should log a debug message when error code is ECONNRESET", () => {
+		const connectionId = "12345";
+		const error = { code: "ECONNRESET" } as NodeJS.ErrnoException;
+        const mockLogger = {
+            debug: vi.fn(),
+        } as unknown as ServerLogger;
+    
+
+		socketErrorHandler({ connectionId, error, log: mockLogger });
+
+		expect(mockLogger.debug).toHaveBeenCalledWith(
+			`Connection ${connectionId} reset`,
+		);
+	});
+
+	it("should throw an error when error code is not handled", () => {
+		const connectionId = "12345";
+		const error = {
+			code: "EUNKNOWN",
+			message: "Unknown error",
+		} as NodeJS.ErrnoException;
+        const mockLogger = {
+            debug: vi.fn(),
+        } as unknown as ServerLogger;
+    
+
+		expect(() =>
+			socketErrorHandler({ connectionId, error, log: mockLogger }),
+		).toThrow(`Socket error: ${error.message} on connection ${connectionId}`);
+	});
+
+});
diff --git a/packages/gateway/src/socketErrorHandler.ts b/packages/gateway/src/socketErrorHandler.ts
new file mode 100644
index 000000000..12df58624
--- /dev/null
+++ b/packages/gateway/src/socketErrorHandler.ts
@@ -0,0 +1,30 @@
+import { getServerLogger, type ServerLogger } from "rusty-motors-shared";
+
+/**
+ * Handles socket errors by logging specific error codes or throwing an error.
+ *
+ * @param {Object} params - The parameters for the socket error handler.
+ * @param {string} params.connectionId - The ID of the connection where the error occurred.
+ * @param {NodeJS.ErrnoException} params.error - The error object containing details of the socket error.
+ * @param {ServerLogger} [params.log] - Optional logger instance for logging error details. Defaults to a server logger named "socketErrorHandler".
+ *
+ * @throws {Error} Throws an error if the socket error code is not handled.
+ */
+export function socketErrorHandler({
+	connectionId,
+	error,
+	log = getServerLogger({
+		name: "socketErrorHandler",
+	}),
+}: {
+	connectionId: string;
+	error: NodeJS.ErrnoException;
+	log?: ServerLogger;
+}) {
+	// Handle socket errors
+	if (error.code == "ECONNRESET") {
+		log.debug(`Connection ${connectionId} reset`);
+		return;
+	}
+	throw Error(`Socket error: ${error.message} on connection ${connectionId}`);
+}