fix: to avoid port overlap prevent sandbox running with other commands

Author: nbbeeken

packages/compass-web/.eslintrc.js

@@ -6,4 +6,17 @@ module.exports = {
     tsconfigRootDir: __dirname,
     project: ['./tsconfig.json'],
   },
+  overrides: [
+    {
+      files: ['**/*.mjs'],
+      parserOptions: {
+        ecmaVersion: 2023,
+        sourceType: 'module',
+      },
+      env: {
+        es2023: true,
+        node: true,
+      },
+    },
+  ],
 };

packages/compass-web/scripts/sync-dist-to-mms.mjs

@@ -16,24 +16,28 @@ if (!process.env.MMS_HOME) {
 function isDevServerRunning(port, host = '127.0.0.1') {
   return new Promise((resolve) => {
     const socket = new net.Socket();
-    socket.setTimeout(1000);
-    socket.once('connect', () => {
-      socket.destroy();
-      resolve(true);
-    });
-    socket.once('timeout', () => {
-      socket.destroy();
-      resolve(false);
-    });
-    socket.once('error', () => {
-      resolve(false);
-    });
-    socket.connect(port, host);
+    socket
+      .setTimeout(1000)
+      .on('connect', () => {
+        socket.destroy();
+        resolve(true);
+      })
+      .on('error', () => {
+        socket.destroy();
+        resolve(false);
+      })
+      .on('timeout', () => {
+        socket.destroy();
+        resolve(false);
+      })
+      .connect(port, host);
   });
 }
 
+const okToRunMMS = !process.argv.includes('--no-mms');
+
 let devServer;
-if (!(await isDevServerRunning(8081))) {
+if (okToRunMMS || !(await isDevServerRunning(8081))) {
   console.log('mms dev server is not running... launching!');
   child_process.execFileSync('pnpm', ['install'], {
     cwd: process.env.MMS_HOME,
@@ -74,6 +78,8 @@ if (!(await isDevServerRunning(8081))) {
   } else {
     console.log('Dev server is ready!');
   }
+} else {
+  console.log('Skipping running MMS dev server...');
 }
 
 const srcDir = path.resolve(import.meta.dirname, '..', 'dist');

scripts/start.md

@@ -6,16 +6,27 @@ Usage: start.mts [-h/--help] [targets... [targetOptions...]]
 
 - `-h, --help` Show this help message
 
-## Targets (can be used in any combination)
+## Targets
 
 - `desktop` Start MongoDB Compass Desktop (default if no targets specified)
 - `sandbox` Start MongoDB Compass Web Sandbox, useful for UI-only changes
 - `sync` Start Cloud Sync, in combination with redirector/redwood can be used to test data explorer changes
+  - `--no-mms` can be passed to the sync subcommand to not run MMS's dev server.
 
-## Examples
+**Note:** `sandbox` must be run alone and cannot be combined with other targets.
 
-start.mts # Start desktop (default)
-start.mts desktop --production # Start desktop explicitly
-start.mts web # Start web sandbox only
-start.mts desktop web # Start both desktop and web
-start.mts sync --flagA -b web -c # Start mms-sync and web
+## Port Configuration
+
+The `desktop` and `sandbox` targets both use the same webpack dev server port (4242) by design. When running both targets simultaneously, the sandbox will automatically detect that the desktop target's webpack dev server is already running and will skip starting its own, sharing the same webpack dev server instance.
+
+Since `sync` must run alone, there are no port conflicts with other targets.
+
+### Well-Known Ports
+
+| Port | Service                | Target               | Description                                     |
+| ---- | ---------------------- | -------------------- | ----------------------------------------------- |
+| 4242 | Webpack Dev Server     | `desktop`, `sandbox` | Serves compiled frontend assets with hot reload |
+| 7777 | HTTP Proxy Server      | `sandbox`            | Express proxy server for Atlas API requests     |
+| 1337 | WebSocket Proxy Server | `sandbox`            | WebSocket proxy for MongoDB connections         |
+| 8080 | Atlas Local Backend    | `sync`               | Local MMS backend server (when MMS_HOME is set) |
+| 8081 | MMS Dev Server         | `sync`               | Local MMS development server                    |

scripts/start.mts

@@ -45,6 +45,18 @@ for (const arg of args) {
   // If arg is not a valid target and no current target, ignore it
 }
 
+// Check for mutually exclusive targets
+if (
+  targets.sandbox.enabled &&
+  (targets.desktop.enabled || targets.sync.enabled)
+) {
+  console.error('Error: sandbox target must be run alone.');
+  console.error(
+    'Please run sandbox by itself, not combined with other targets.'
+  );
+  process.exit(1);
+}
+
 // If no targets specified, default to desktop
 if (
   !targets.desktop.enabled &&
@@ -62,14 +74,14 @@ const subProcesses: child_process.ChildProcess[] = [];
 async function cleanup(signal: NodeJS.Signals) {
   for (const p of subProcesses) p.kill(signal);
   console.log('\nstart    | requested termination.');
-  await timers.setTimeout(5000);
+  await timers.setTimeout(10_000);
   const stillRunning = subProcesses.filter((p) => p.exitCode === null);
   for (const p of stillRunning) p.kill('SIGKILL');
   console.log('\nstart    | done.');
   process.exit(0);
 }
 
-process.on('SIGINT', cleanup).on('SIGTERM', cleanup);
+process.once('SIGINT', cleanup).once('SIGTERM', cleanup);
 
 // Helper function to create a transform stream that prefixes lines
 function createPrefixTransform(prefix: string) {
@@ -125,7 +137,7 @@ function spawnTarget(
       ...(args.length ? ['--', ...args] : []),
     ],
     {
-      stdio: 'pipe',
+      stdio: ['pipe', 'pipe', 'pipe'], // stdin, stdout, stderr all piped
       env: { ...process.env, ...colorEnv },
     },
   ];
@@ -206,3 +218,12 @@ if (targets.sandbox.enabled) {
     )
   );
 }
+
+// Forward stdin to all subprocesses using pipeline
+for (const subProcess of subProcesses) {
+  if (subProcess.stdin)
+    pipeline(process.stdin, subProcess.stdin, { end: false }).catch((err) => {
+      if (err.code !== 'EPIPE' && err.code !== 'ERR_STREAM_PREMATURE_CLOSE')
+        console.error(`start    | stdin pipeline error:`, err);
+    });
+}