Fix unresolved promise

src/commands/optimize.ts

@@ -918,19 +918,16 @@ export const optimize: CliSubcommand = {
       spinner.start(`Updating ${lockName}...`)
       try {
         if (isNpm) {
-          await shadowNpmInstall({
-            ipc: {
-              [SOCKET_CLI_UPDATE_OVERRIDES_IN_PACKAGE_LOCK_FILE]: true
-            }
-          })
+          const ipc = {
+            [SOCKET_CLI_UPDATE_OVERRIDES_IN_PACKAGE_LOCK_FILE]: true
+          }
+          await shadowNpmInstall({ ipc })
           // TODO: This is a temporary workaround for a `npm ci` bug where it
           // will error out after Socket Optimize generates a lock file. More
           // investigation is needed.
           await shadowNpmInstall({
             flags: ['--ignore-scripts', '--package-lock-only'],
-            ipc: {
-              [SOCKET_CLI_UPDATE_OVERRIDES_IN_PACKAGE_LOCK_FILE]: true
-            }
+            ipc
           })
         } else {
           // All package managers support the "install" command.

src/constants.ts

@@ -1,4 +1,4 @@
-import { realpathSync } from 'node:fs'
+import { realpathSync, writeFileSync } from 'node:fs'
 import path from 'node:path'
 import process from 'node:process'
 
@@ -103,27 +103,32 @@ const LAZY_IPC = (() => {
     _ipc[key] = false
     defineGetter(ipc, key, () => _ipc[key])
   }
-  void new Promise<void>(resolve => {
-    const onmessage = (ipcData_: Serializable) => {
-      const ipcData: { [key: string]: any } = {
-        __proto__: null,
-        ...(isObject(ipcData_) ? ipcData_ : {})
+  // A forked subprocess will have the 'send' method.
+  // https://nodejs.org/api/child_process.html#subprocesssendmessage-sendhandle-options-callback
+  if (typeof process.send === 'function') {
+    void new Promise<void>(resolve => {
+      const onmessage = (ipcData_: Serializable) => {
+        finish()
+        const ipcData: { [key: string]: any } = {
+          __proto__: null,
+          ...(isObject(ipcData_) ? ipcData_ : {})
+        }
+        for (const key of keys) {
+          _ipc[key] = ipcData[key]
+        }
       }
-      for (const key of keys) {
-        _ipc[key] = ipcData[key]
-      }
-      resolve()
-    }
-    process.once('message', onmessage)
-    abortSignal.addEventListener(
-      'abort',
-      () => {
+      const finish = () => {
+        abortSignal.removeEventListener('abort', finish)
         process.removeListener('message', onmessage)
         resolve()
-      },
-      { once: true }
-    )
-  })
+      }
+      abortSignal.addEventListener('abort', finish, { once: true })
+      process.on('message', onmessage)
+      // The timeout of 100ms is to prevent an unresolved promised. It should be
+      // more than enough time for the IPC handshake.
+      setTimeout(finish, 100)
+    })
+  }
   return () => Object.freeze(ipc)
 })()