Fix Ubuntu setup: add server.js, correct build instructions, add setup-ubuntu.sh

[Copilot]

Two broken flows: node server.js failed with MODULE_NOT_FOUND because server.js was never in the repo; emcmake cmake .. failed because the repo has no CMakeLists.txt — it uses PowerShell scripts that invoke emcc directly.

Changes

server.js (new)

• Express + ws WebSocket server; fixes the MODULE_NOT_FOUND error
• Serves only web-build/project/emscripten/ (WASM output) and web-build/data/ (assets) — not the repo root, avoiding source-file exposure
• Binds to 127.0.0.1 by default; override with HOST=0.0.0.0
• WebSocket payload logging truncated to 120 chars

package.json (new)

• Declares express ^4.18.2 and ws ^8.17.1 (patched past DoS-vulnerable 8.16.x)

setup-ubuntu.sh (new)

• End-to-end bash script: apt deps → Node.js 20 → PowerShell Core → emsdk at ~/emsdk (the path build_web.ps1 resolves via ../../../emsdk) → PR Convert fixed 256×256 world to infinite world with dynamic chunk loading/unloading #5 checkout → pwsh build_web.ps1 → npm install → node server.js
• Handles: existing emsdk dir, npm not found post-install, missing build_web.ps1 (skips build with guidance)

readme.MD (updated)

• Replaced placeholder content with Ubuntu setup/build/serve instructions
• Troubleshooting section covering: MODULE_NOT_FOUND, CMake confusion, missing npm, stale emsdk, missing build script

Original prompt

Update Ubuntu setup/build/serve instructions for MCPE-WASM PR #5 so that:

1. The WebSocket server file server.js is actually created before running node server.js, avoiding MODULE_NOT_FOUND.
2. The build instructions do not assume a top-level CMakeLists.txt exists; detect correct build system and/or build directory and adjust commands accordingly.
3. Provide a robust bash script and README section that:
   • installs dependencies (Node.js, npm, emsdk)
   • clones repo and checks out PR branch infinite-world
   • builds the wasm output using the repo's actual build instructions
   • serves static files and runs a WebSocket server for world connection
   • includes common troubleshooting for missing CMakeLists, missing npm, and existing emsdk directory.

Context from user logs:

• emcmake cmake .. fails: CMake Error: The source directory "/home/admin1/MCPE-WASM" does not appear to contain CMakeLists.txt.
• node server.js fails: Error: Cannot find module '/home/admin1/MCPE-WASM/server.js'.

Acceptance criteria:

• After following the updated commands, ls -l server.js exists and node server.js starts successfully.
• Build step either succeeds or is conditionally skipped with clear guidance based on repo structure.

The following is the prior conversation context from the user's chat exploration (may be truncated):

User: make me a series of linux commands to build/ set this up on ubuntu and serve the repo (with websockets for world conevction

Assistant: Based on the pull request for MCPE-WASM (a Minecraft Pocket Edition WebAssembly project), here's a series of Linux commands to build and serve the repo on Ubuntu:

#!/bin/bash

# Update system packages
sudo apt update && sudo apt upgrade -y

# Install essential build tools
sudo apt install -y build-essential cmake git

# Install Node.js and npm (for serving with WebSocket support)
curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
sudo apt install -y nodejs

# Install Emscripten (WebAssembly toolchain)
cd ~
git clone https://github.com/emscripten-core/emsdk.git
cd emsdk
./emsdk install latest
./emsdk activate latest
source ./emsdk_env.sh

# Clone the repository
cd ~
git clone https://github.com/sriail/MCPE-WASM.git
cd MCPE-WASM

# Checkout the PR branch with infinite world changes
git fetch origin pull/5/head:infinite-world
git checkout infinite-world

# Build the project with Emscripten
mkdir -p build
cd build
emcmake cmake ..
emmake make

# Install a simple WebSocket-capable HTTP server
cd ~/MCPE-WASM
npm init -y
npm install ws express

# Create a server file for serving with WebSocket support
cat > server.js << 'EOF'
const express = require('express');
const http = require('http');
const WebSocket = require('ws');
const path = require('path');

const app = express();
const server = http.createServer(app);
const wss = new WebSocket.Server({ server });

// Serve static files
app.use(express.static(path.join(__dirname, 'build')));
app.use(express.static(__dirname));

// WebSocket connection for world data
wss.on('connection', (ws) => {
  console.log('Client connected');
  
  ws.on('message', (message) => {
    console.log('Received:', message.toString());
    // Broadcast to all connected clients (for multiplayer world sync)
    wss.clients.forEach((client) => {
      if (client !== ws && client.readyState === WebSocket.OPEN) {
        client.send(message);
      }
    });
  });

  ws.on('close', () => {
    console.log('Client disconnected');
  });
});

const PORT = process.env.PORT || 8080;
server.listen(PORT, '0.0.0.0', () => {
  console.log(`Server running on http://localhost:${PORT}`);
  console.log(`WebSocket server ready for world connections`);
});
EOF

# Make the script executable
chmod +x server.js

# Start the server
node server.js

Quick setup commands (copy-paste):

# 1. Install dependencies
sudo apt update && sudo apt upgrade -y
sudo apt install -y build-essential cmake git
curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
sudo apt install -y nodejs

# 2. Setup Emscripten
cd ~ && git clone https://github.com/emscripten-core/emsdk.git
cd emsdk && ./emsdk install latest && ./emsdk activate latest
source ./emsdk_env.sh

# 3. Clone and build
cd ~ && git clone https://github.com/sriail/MCPE-WASM.git
cd MCPE-WASM
git fetch origin pull/5/head:infinite-world && git checkout infinite-world
mkdir -p build && cd build
emcmake cmake .. && emmake make

# 4. Setup server
cd ~/MCPE-WASM
npm init -y
npm install ws express

# 5. Create and run the server (use the server.js code above)
# Then run:
node server.js

Access the application:

• Open your browser to http://localhost:8080
• WebSocket connections for world data will automatically connect to ws://localhost:8080

Notes:

• The WebSocket server handles real-time chunk loading/unloading for the infinite world feature
• If you need to persist world data, you'll want to add storage (e.g., Redis o...

This pull request was created from Copilot chat.