From d744fda77207ecf1fa4bc1cd3d32eaa403deca9f Mon Sep 17 00:00:00 2001
From: Damien Arrachequesne <damien.arrachequesne@gmail.com>
Date: Wed, 13 Sep 2023 15:52:56 +0200
Subject: [PATCH] docs: improve example with express-session

The example is now available with different syntaxes:

- CommonJS
- ES modules
- TypeScript

Related: https://github.com/socketio/socket.io/pull/4787
---
 .../{ => cjs}/index.html                      |  0
 examples/express-session-example/cjs/index.js | 66 +++++++++++++++++
 .../express-session-example/cjs/package.json  | 15 ++++
 .../express-session-example/esm/index.html    | 61 ++++++++++++++++
 .../{ => esm}/index.js                        |  4 +-
 .../{ => esm}/package.json                    |  0
 .../express-session-example/ts/index.html     | 61 ++++++++++++++++
 examples/express-session-example/ts/index.ts  | 72 +++++++++++++++++++
 .../express-session-example/ts/package.json   | 20 ++++++
 .../express-session-example/ts/tsconfig.json  | 11 +++
 10 files changed, 308 insertions(+), 2 deletions(-)
 rename examples/express-session-example/{ => cjs}/index.html (100%)
 create mode 100644 examples/express-session-example/cjs/index.js
 create mode 100644 examples/express-session-example/cjs/package.json
 create mode 100644 examples/express-session-example/esm/index.html
 rename examples/express-session-example/{ => esm}/index.js (92%)
 rename examples/express-session-example/{ => esm}/package.json (100%)
 create mode 100644 examples/express-session-example/ts/index.html
 create mode 100644 examples/express-session-example/ts/index.ts
 create mode 100644 examples/express-session-example/ts/package.json
 create mode 100644 examples/express-session-example/ts/tsconfig.json

diff --git a/examples/express-session-example/index.html b/examples/express-session-example/cjs/index.html
similarity index 100%
rename from examples/express-session-example/index.html
rename to examples/express-session-example/cjs/index.html
diff --git a/examples/express-session-example/cjs/index.js b/examples/express-session-example/cjs/index.js
new file mode 100644
index 0000000000..e3aaac83ee
--- /dev/null
+++ b/examples/express-session-example/cjs/index.js
@@ -0,0 +1,66 @@
+const express = require("express");
+const { createServer } = require("node:http");
+const { join } = require("node:path");
+const { Server } = require("socket.io");
+const session = require("express-session");
+
+const port = process.env.PORT || 3000;
+
+const app = express();
+const httpServer = createServer(app);
+
+const sessionMiddleware = session({
+  secret: "changeit",
+  resave: true,
+  saveUninitialized: true,
+});
+
+app.use(sessionMiddleware);
+
+app.get("/", (req, res) => {
+  res.sendFile(join(__dirname, "index.html"));
+});
+
+app.post("/incr", (req, res) => {
+  const session = req.session;
+  session.count = (session.count || 0) + 1;
+  res.status(200).end("" + session.count);
+
+  io.to(session.id).emit("current count", session.count);
+});
+
+app.post("/logout", (req, res) => {
+  const sessionId = req.session.id;
+  req.session.destroy(() => {
+    // disconnect all Socket.IO connections linked to this session ID
+    io.to(sessionId).disconnectSockets();
+    res.status(204).end();
+  });
+});
+
+const io = new Server(httpServer);
+
+io.engine.use(sessionMiddleware);
+
+io.on("connection", (socket) => {
+  const req = socket.request;
+
+  socket.join(req.session.id);
+
+  socket.on("incr", (cb) => {
+    req.session.reload((err) => {
+      if (err) {
+        // session has expired
+        return socket.disconnect();
+      }
+      req.session.count = (req.session.count || 0) + 1;
+      req.session.save(() => {
+        cb(req.session.count);
+      });
+    });
+  });
+});
+
+httpServer.listen(port, () => {
+  console.log(`application is running at: http://localhost:${port}`);
+});
diff --git a/examples/express-session-example/cjs/package.json b/examples/express-session-example/cjs/package.json
new file mode 100644
index 0000000000..af1aeccf8b
--- /dev/null
+++ b/examples/express-session-example/cjs/package.json
@@ -0,0 +1,15 @@
+{
+  "name": "express-session-example",
+  "version": "0.0.1",
+  "private": true,
+  "type": "commonjs",
+  "description": "Example with express-session (https://github.com/expressjs/session)",
+  "scripts": {
+    "start": "node index.js"
+  },
+  "dependencies": {
+    "express": "~4.17.3",
+    "express-session": "~1.17.2",
+    "socket.io": "^4.7.2"
+  }
+}
diff --git a/examples/express-session-example/esm/index.html b/examples/express-session-example/esm/index.html
new file mode 100644
index 0000000000..890fca1c6c
--- /dev/null
+++ b/examples/express-session-example/esm/index.html
@@ -0,0 +1,61 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <title>Example with express-session</title>
+  </head>
+  <body>
+    <button onclick="incrementWithFetch()">Increment with fetch()</button>
+    <button onclick="logout()">Logout</button>
+    <p>Count: <span id="httpCount">0</span></p>
+
+    <button onclick="incrementWithEmit()">
+      Increment with Socket.IO emit()
+    </button>
+    <p>Status: <span id="ioStatus">disconnected</span></p>
+    <p>Count: <span id="ioCount">0</span></p>
+
+    <script src="/socket.io/socket.io.js"></script>
+    <script>
+      const httpCount = document.getElementById("httpCount");
+      const ioStatus = document.getElementById("ioStatus");
+      const ioCount = document.getElementById("ioCount");
+
+      const socket = io({
+        // with WebSocket only
+        // transports: ["websocket"],
+      });
+
+      async function incrementWithFetch() {
+        const response = await fetch("/incr", {
+          method: "post",
+        });
+        httpCount.innerText = await response.text();
+      }
+
+      function logout() {
+        fetch("/logout", {
+          method: "post",
+        });
+      }
+
+      async function incrementWithEmit() {
+        socket.emit("incr", (count) => {
+          ioCount.innerText = count;
+        });
+      }
+
+      socket.on("connect", () => {
+        ioStatus.innerText = "connected";
+      });
+
+      socket.on("disconnect", () => {
+        ioStatus.innerText = "disconnected";
+      });
+
+      socket.on("current count", (count) => {
+        ioCount.innerText = count;
+      });
+    </script>
+  </body>
+</html>
diff --git a/examples/express-session-example/index.js b/examples/express-session-example/esm/index.js
similarity index 92%
rename from examples/express-session-example/index.js
rename to examples/express-session-example/esm/index.js
index e3eed9c23c..aec0d17d9c 100644
--- a/examples/express-session-example/index.js
+++ b/examples/express-session-example/esm/index.js
@@ -1,5 +1,5 @@
 import express from "express";
-import { createServer } from "http";
+import { createServer } from "node:http";
 import { Server } from "socket.io";
 import session from "express-session";
 
@@ -17,7 +17,7 @@ const sessionMiddleware = session({
 app.use(sessionMiddleware);
 
 app.get("/", (req, res) => {
-  res.sendFile("./index.html", { root: process.cwd() });
+  res.sendFile(new URL("./index.html", import.meta.url).pathname);
 });
 
 app.post("/incr", (req, res) => {
diff --git a/examples/express-session-example/package.json b/examples/express-session-example/esm/package.json
similarity index 100%
rename from examples/express-session-example/package.json
rename to examples/express-session-example/esm/package.json
diff --git a/examples/express-session-example/ts/index.html b/examples/express-session-example/ts/index.html
new file mode 100644
index 0000000000..890fca1c6c
--- /dev/null
+++ b/examples/express-session-example/ts/index.html
@@ -0,0 +1,61 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <title>Example with express-session</title>
+  </head>
+  <body>
+    <button onclick="incrementWithFetch()">Increment with fetch()</button>
+    <button onclick="logout()">Logout</button>
+    <p>Count: <span id="httpCount">0</span></p>
+
+    <button onclick="incrementWithEmit()">
+      Increment with Socket.IO emit()
+    </button>
+    <p>Status: <span id="ioStatus">disconnected</span></p>
+    <p>Count: <span id="ioCount">0</span></p>
+
+    <script src="/socket.io/socket.io.js"></script>
+    <script>
+      const httpCount = document.getElementById("httpCount");
+      const ioStatus = document.getElementById("ioStatus");
+      const ioCount = document.getElementById("ioCount");
+
+      const socket = io({
+        // with WebSocket only
+        // transports: ["websocket"],
+      });
+
+      async function incrementWithFetch() {
+        const response = await fetch("/incr", {
+          method: "post",
+        });
+        httpCount.innerText = await response.text();
+      }
+
+      function logout() {
+        fetch("/logout", {
+          method: "post",
+        });
+      }
+
+      async function incrementWithEmit() {
+        socket.emit("incr", (count) => {
+          ioCount.innerText = count;
+        });
+      }
+
+      socket.on("connect", () => {
+        ioStatus.innerText = "connected";
+      });
+
+      socket.on("disconnect", () => {
+        ioStatus.innerText = "disconnected";
+      });
+
+      socket.on("current count", (count) => {
+        ioCount.innerText = count;
+      });
+    </script>
+  </body>
+</html>
diff --git a/examples/express-session-example/ts/index.ts b/examples/express-session-example/ts/index.ts
new file mode 100644
index 0000000000..7e2a47ca7e
--- /dev/null
+++ b/examples/express-session-example/ts/index.ts
@@ -0,0 +1,72 @@
+import express = require("express");
+import { createServer } from "http";
+import { Server } from "socket.io";
+import session from "express-session";
+import { type Request } from "express";
+
+declare module "express-session" {
+  interface SessionData {
+    count: number;
+  }
+}
+
+const port = process.env.PORT || 3000;
+
+const app = express();
+const httpServer = createServer(app);
+
+const sessionMiddleware = session({
+  secret: "changeit",
+  resave: true,
+  saveUninitialized: true,
+});
+
+app.use(sessionMiddleware);
+
+app.get("/", (req, res) => {
+  res.sendFile(new URL("./index.html", import.meta.url).pathname);
+});
+
+app.post("/incr", (req, res) => {
+  const session = req.session;
+  session.count = (session.count || 0) + 1;
+  res.status(200).end("" + session.count);
+
+  io.to(session.id).emit("current count", session.count);
+});
+
+app.post("/logout", (req, res) => {
+  const sessionId = req.session.id;
+  req.session.destroy(() => {
+    // disconnect all Socket.IO connections linked to this session ID
+    io.to(sessionId).disconnectSockets();
+    res.status(204).end();
+  });
+});
+
+const io = new Server(httpServer);
+
+io.engine.use(sessionMiddleware);
+
+io.on("connection", (socket) => {
+  const req = socket.request as Request;
+
+  socket.join(req.session.id);
+
+  socket.on("incr", (cb) => {
+    req.session.reload((err) => {
+      if (err) {
+        // session has expired
+        return socket.disconnect();
+      }
+      req.session.count = (req.session.count || 0) + 1;
+      req.session.save(() => {
+        cb(req.session.count);
+      });
+    });
+  });
+});
+
+httpServer.listen(port, () => {
+  console.log(`application is running at: http://localhost:${port}`);
+});
diff --git a/examples/express-session-example/ts/package.json b/examples/express-session-example/ts/package.json
new file mode 100644
index 0000000000..48489fa51d
--- /dev/null
+++ b/examples/express-session-example/ts/package.json
@@ -0,0 +1,20 @@
+{
+  "name": "express-session-example",
+  "version": "0.0.1",
+  "private": true,
+  "type": "module",
+  "description": "Example with express-session (https://github.com/expressjs/session)",
+  "scripts": {
+    "start": "ts-node index.ts"
+  },
+  "dependencies": {
+    "@types/express": "^4.17.17",
+    "@types/express-session": "^1.17.7",
+    "@types/node": "^20.6.0",
+    "express": "~4.17.3",
+    "express-session": "~1.17.2",
+    "socket.io": "^4.7.2",
+    "ts-node": "^10.9.1",
+    "typescript": "^5.2.2"
+  }
+}
diff --git a/examples/express-session-example/ts/tsconfig.json b/examples/express-session-example/ts/tsconfig.json
new file mode 100644
index 0000000000..fe03ed87a1
--- /dev/null
+++ b/examples/express-session-example/ts/tsconfig.json
@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "module": "NodeNext",
+    "moduleResolution": "NodeNext",
+    "target": "ES2022",
+    "strict": true
+  },
+  "ts-node": {
+    "esm": true
+  }
+}