From d1754841e9330048ecb9d6bfc84d6fae8d1ee3ba Mon Sep 17 00:00:00 2001
From: iifawzi <iifawzie@gmail.com>
Date: Sat, 15 Oct 2022 22:06:30 +0200
Subject: [PATCH] Adding the trailingSlash option

Signed-off-by: iifawzi <iifawzie@gmail.com>
---
 lib/socket.ts            | 26 +++++++++++++++++---------
 test/engine.io-client.js |  6 ++++++
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/lib/socket.ts b/lib/socket.ts
index 90b4840ab..6864752ba 100644
--- a/lib/socket.ts
+++ b/lib/socket.ts
@@ -206,6 +206,12 @@ export interface SocketOptions {
    */
   path: string;
 
+  /**
+   * Should we add a trailing slash to the path?
+   * @default true
+   */
+  trailingSlash: boolean;
+
   /**
    * Either a single protocol string or an array of protocol strings. These strings are used to indicate sub-protocols,
    * so that a single server can implement multiple WebSocket sub-protocols (for example, you might want one server to
@@ -323,17 +329,19 @@ export class Socket extends Emitter<{}, {}, SocketReservedEvents> {
         upgrade: true,
         timestampParam: "t",
         rememberUpgrade: false,
+        trailingSlash: true,
         rejectUnauthorized: true,
         perMessageDeflate: {
-          threshold: 1024
+          threshold: 1024,
         },
         transportOptions: {},
-        closeOnBeforeunload: true
+        closeOnBeforeunload: true,
       },
       opts
     );
 
-    this.opts.path = this.opts.path.replace(/\/$/, "") + "/";
+    this.opts.path =
+      this.opts.path.replace(/\/$/, "") + (this.opts.trailingSlash ? "/" : "");
 
     if (typeof this.opts.query === "string") {
       this.opts.query = decode(this.opts.query);
@@ -365,7 +373,7 @@ export class Socket extends Emitter<{}, {}, SocketReservedEvents> {
       if (this.hostname !== "localhost") {
         this.offlineEventListener = () => {
           this.onClose("transport close", {
-            description: "network connection lost"
+            description: "network connection lost",
           });
         };
         addEventListener("offline", this.offlineEventListener, false);
@@ -404,7 +412,7 @@ export class Socket extends Emitter<{}, {}, SocketReservedEvents> {
         socket: this,
         hostname: this.hostname,
         secure: this.secure,
-        port: this.port
+        port: this.port,
       }
     );
 
@@ -472,7 +480,7 @@ export class Socket extends Emitter<{}, {}, SocketReservedEvents> {
       .on("drain", this.onDrain.bind(this))
       .on("packet", this.onPacket.bind(this))
       .on("error", this.onError.bind(this))
-      .on("close", reason => this.onClose("transport close", reason));
+      .on("close", (reason) => this.onClose("transport close", reason));
   }
 
   /**
@@ -493,7 +501,7 @@ export class Socket extends Emitter<{}, {}, SocketReservedEvents> {
 
       debug('probe transport "%s" opened', name);
       transport.send([{ type: "ping", data: "probe" }]);
-      transport.once("packet", msg => {
+      transport.once("packet", (msg) => {
         if (failed) return;
         if ("pong" === msg.type && "probe" === msg.data) {
           debug('probe transport "%s" pong', name);
@@ -540,7 +548,7 @@ export class Socket extends Emitter<{}, {}, SocketReservedEvents> {
     }
 
     // Handle any error that happens while probing
-    const onerror = err => {
+    const onerror = (err) => {
       const error = new Error("probe error: " + err);
       // @ts-ignore
       error.transport = transport.name;
@@ -819,7 +827,7 @@ export class Socket extends Emitter<{}, {}, SocketReservedEvents> {
     const packet = {
       type: type,
       data: data,
-      options: options
+      options: options,
     };
     this.emitReserved("packetCreate", packet);
     this.writeBuffer.push(packet);
diff --git a/test/engine.io-client.js b/test/engine.io-client.js
index 1d7677dd0..97508218b 100644
--- a/test/engine.io-client.js
+++ b/test/engine.io-client.js
@@ -58,6 +58,12 @@ describe("engine.io-client", () => {
     expect(client.port).to.be("8080");
   });
 
+  it("should properly handle the trailingSlash option", () => {
+    const client = new Socket({ host: "localhost", trailingSlash: false });
+    expect(client.hostname).to.be("localhost");
+    expect(client.opts.path).to.be("/engine.io");
+  });
+
   it("should properly parse an IPv6 uri without port", () => {
     const client = new Socket("http://[::1]");
     expect(client.hostname).to.be("::1");