Serverless is unable to find the handler in nestjs - node.js

Question

I am trying to deploy my NestJS project to AWS lambda with serverless framework, I followed official documentation
I created a file serverless.ts in src directory along with main.ts file.
When I run sls offline, it successfull runs and gives following output:
Running "serverless" from node_modules
Starting Offline at stage dev (us-east-1)
Offline [http for lambda] listening on http://localhost:3002
Function names exposed for local invocation by aws-sdk:
* main: projectName-dev-main
┌────────────────────────────────────────────────────────────────────────┐
│ │
│ ANY | http://localhost:4000/ │
│ POST | http://localhost:4000/2015-03-31/functions/main/invocations │
│ ANY | http://localhost:4000/{proxy*} │
│ POST | http://localhost:4000/2015-03-31/functions/main/invocations │
│ │
└────────────────────────────────────────────────────────────────────────┘
Server ready: http://localhost:4000 🚀
But when I open the localhost URL http://localhost:4000, I get 502 Bad gateway and
following error.
ANY / (λ: main)
✖ Unhandled exception in handler 'main'.
✖ Error: Cannot find module 'main'
Require stack:
- /home/my-PC/Desktop/projectName/node_modules/serverless-offline/src/lambda/handler-runner/in-process-runner/aws-lambda-ric/UserFunction.js
✖ Runtime.ImportModuleError: Error: Cannot find module 'main'
Require stack:
- /home/my-PC/Desktop/projectName/node_modules/serverless-offline/src/lambda/handler-runner/in-process-runner/aws-lambda-ric/UserFunction.js
at _loadUserApp (/home/my-PC/Desktop/projectName/node_modules/serverless-offline/src/lambda/handler-runner/in-process-runner/aws-lambda-ric/UserFunction.js:310:15)
at async module.exports.load (/home/my-PC/Desktop/projectName/node_modules/serverless-offline/src/lambda/handler-runner/in-process-runner/aws-lambda-ric/UserFunction.js:341:21)
at async InProcessRunner.run (file:///home/my-PC/Desktop/projectName/node_modules/serverless-offline/src/lambda/handler-runner/in-process-runner/InProcessRunner.js:41:21)
at async MessagePort.<anonymous> (file:///home/my-PC/Desktop/projectName/node_modules/serverless-offline/src/lambda/handler-runner/worker-thread-runner/workerThreadHelper.js:25:14)
Here is code:
main.ts
import { NestFactory } from '#nestjs/core';
import { ValidationPipe } from '#nestjs/common';
import { AppModule } from './app.module';
async function bootstrap() {
process.env.TZ = 'Asia/Calcutta';
const app = await NestFactory.create(AppModule);
const port = process.env.PORT || 3000;
app.useGlobalPipes(new ValidationPipe({ whitelist: true }));
await app.listen(port);
}
bootstrap();
serverless.ts
import { NestFactory } from '#nestjs/core';
import serverlessExpress from '#vendia/serverless-express';
import { Callback, Context, Handler } from 'aws-lambda';
import { AppModule } from './app.module';
let server: Handler;
async function bootstrap(): Promise<Handler> {
const app = await NestFactory.create(AppModule);
await app.init();
const expressApp = app.getHttpAdapter().getInstance();
return serverlessExpress({ app: expressApp });
}
export const handler: Handler = async (
event: any,
context: Context,
callback: Callback,
) => {
server = server ?? (await bootstrap());
return server(event, context, callback);
};
serverless.yaml
service: myProject
useDotenv: true
plugins:
- serverless-offline
# - serverless-plugin-optimize
provider:
name: aws
runtime: nodejs16.x
region: us-east-1
profile: default
memorySize: 128
stage: dev
environment:
TZ: ${env:TZ}
functions:
main:
handler: dist/main.handler
events:
- http:
method: ANY
path: /
- http:
method: ANY
path: '{proxy+}'
custom:
serverless-offline:
noPrependStageInUrl: true
httpPort: 4000