Fix wrapper.start not actually waiting for anything

src/node/wrapper.ts

@@ -208,9 +208,16 @@ export class WrapperProcess {
         this.relaunch()
       })
     }
-
     if (!this.started) {
-      this.started = this.spawn().then((child) => {
+      this.started = this._start()
+    }
+    return this.started
+  }
+
+  private async _start(): Promise<void> {
+    const child = this.spawn()
+    this.process = child
+
     // Log both to stdout and to the log directory.
     if (child.stdout) {
       child.stdout.pipe(this.logStdoutStream)
@@ -220,20 +227,18 @@ export class WrapperProcess {
       child.stderr.pipe(this.logStderrStream)
       child.stderr.pipe(process.stderr)
     }
+
     logger.debug(`spawned inner process ${child.pid}`)
-        ipcMain.handshake(child).then(() => {
+
+    await ipcMain.handshake(child)
+
     child.once("exit", (code) => {
       logger.debug(`inner process ${child.pid} exited unexpectedly`)
       ipcMain.exit(code || 0)
     })
-        })
-        this.process = child
-      })
-    }
-    return this.started
   }
 
-  private async spawn(): Promise<cp.ChildProcess> {
+  private spawn(): cp.ChildProcess {
     // Flags to pass along to the Node binary.
     let nodeOptions = `${process.env.NODE_OPTIONS || ""} ${(this.options && this.options.nodeOptions) || ""}`
     if (!/max_old_space_size=(\d+)/g.exec(nodeOptions)) {