[Refactor] separate ApplicationContext

src/app.context.ts

@@ -0,0 +1,10 @@
+import { NestFactory } from '@nestjs/core';
+import { AppModule } from './app.module';
+
+let context = null;
+export const ApplicationContext = async () => {
+  if (!context) {
+    context = await NestFactory.create(AppModule);
+  }
+  return context;
+}

src/bull-queue/processors/btcprice.processor.ts

@@ -1,10 +1,10 @@
-import { NestFactory } from '@nestjs/core';
+import { ApplicationContext } from '../../app.context';
 import { BtcPriceModule } from '../../btcprice/btcprice.module';
 import { BtcPriceService } from '../../btcprice/btcprice.service';
 
 const BtcPriceProcessor = async (job) => {
 
-  const context = await NestFactory.createApplicationContext(BtcPriceModule);
+  const context = await ApplicationContext();
   const btcPriceService = context.get(BtcPriceService);
 
   return await btcPriceService.fetch(job.data.currency)

src/main.ts

@@ -1,9 +1,8 @@
-import { NestFactory } from '@nestjs/core';
-import { AppModule } from './app.module';
+import { ApplicationContext } from './app.context';
 import 'dotenv/config';
 
 async function bootstrap() {
-  const app = await NestFactory.create(AppModule);
+  const app = await ApplicationContext();
   await app.listen(process.env.APP_PORT);
 }