fix: address additional CodeRabbit review comments

- Fix missing parentheses in tests/minapp/index.ts toString() call
- Add error handling to gRPC exchange promise chain
- Remove async modifier from globalsetup.ts (no await needed)
- Add race condition protection for pool initialization
- Document DEV_CERT_PRIVATE_KEY as development-only test key

Author: jleni

src/Zemu.ts

@@ -90,6 +90,7 @@ export default class Zemu {
   private static containerPool: ContainerPool | null = null
   private static poolEnabled: boolean = process.env.ZEMU_DISABLE_POOL !== 'true'
   private static poolInitialized = false
+  private static poolInitPromise: Promise<void> | null = null
   private pooledContainer: IPooledContainer | null = null
   private usingPool = false
 
@@ -258,7 +259,10 @@ export default class Zemu {
     try {
       // Initialize pool if not already done
       if (!Zemu.poolInitialized && Zemu.containerPool === null) {
-        await Zemu.initializePool()
+        if (!Zemu.poolInitPromise) {
+          Zemu.poolInitPromise = Zemu.initializePool()
+        }
+        await Zemu.poolInitPromise
       }
 
       if (!Zemu.containerPool || !Zemu.poolInitialized) {

src/emulator.ts

@@ -18,6 +18,8 @@ import path from 'node:path'
 import { Transform } from 'node:stream'
 import Docker, { type Container, type ContainerInfo } from 'dockerode'
 
+// Development certificate key for emulator testing only - NOT FOR PRODUCTION USE
+// This is a well-known test key used by the Ledger emulator for development purposes
 export const DEV_CERT_PRIVATE_KEY = 'ff701d781f43ce106f72dc26a46b6a83e053b5d07bb3d4ceab79c91ca822a66b'
 export const BOLOS_SDK = '/project/deps/nanos-secure-sdk'
 export const DEFAULT_APP_PATH = '/project/app/bin'

src/grpc/index.ts

@@ -34,9 +34,15 @@ export default class GRPCRouter {
     this.server.addService(rpcDefinition.ledger_go.ZemuCommand.service, {
       Exchange(call: any, callback: any, ctx = self) {
         // eslint-disable-next-line @typescript-eslint/no-unsafe-argument
-        void ctx.httpTransport.exchange(call.request.command).then((response: Buffer) => {
-          callback(null, { reply: response })
-        })
+        void ctx.httpTransport
+          .exchange(call.request.command)
+          .then((response: Buffer) => {
+            callback(null, { reply: response })
+          })
+          .catch((err: unknown) => {
+            // propagate transport failure back to the client
+            callback(err as Error)
+          })
       },
     })
     this.server.bindAsync(this.serverAddress, ServerCredentials.createInsecure(), (err, port) => {

tests/globalsetup.ts

@@ -7,6 +7,6 @@ const catchExit = () => {
   })
 }
 
-module.exports = async () => {
-  await catchExit()
+module.exports = () => {
+  catchExit()
 }

tests/minapp/index.ts

@@ -25,7 +25,7 @@ export function processErrorResponse(response: any) {
       if (Object.hasOwn(response, 'statusCode')) {
         return {
           return_code: response.statusCode,
-          error_message: response.statusCode.toString,
+          error_message: response.statusCode.toString(),
         }
       }