Assist_Design/apps/bff/src/main.ts

import { Logger, type INestApplication } from "@nestjs/common";

import { bootstrap } from "./app/bootstrap";

const logger = new Logger("Main");
let app: INestApplication | null = null;

const signals: NodeJS.Signals[] = ["SIGINT", "SIGTERM"];
for (const signal of signals) {
  process.once(signal, async () => {
    logger.log(`Received ${signal}. Closing Nest application...`);

    if (!app) {
      logger.warn("Nest application not initialized. Exiting immediately.");
      process.exit(0);
      return;
    }

    try {
      await app.close();
      logger.log("Nest application closed gracefully.");
    } catch (error) {
      const resolvedError = error as Error;
      logger.error(
        `Error during Nest application shutdown: ${resolvedError.message}`,
        resolvedError.stack
      );
    } finally {
      process.exit(0);
    }
  });
}

void bootstrap()
  .then((startedApp) => {
    app = startedApp;
  })
  .catch((error) => {
    const resolvedError = error as Error;
    logger.error(
      `Failed to bootstrap the Nest application: ${resolvedError.message}`,
      resolvedError.stack
    );
    process.exit(1);
  });