using node-postgres (`pg`) in AWS Lambda

lambda.ts

import type { Handler } from "aws-lambda";
import { Pool } from "pg";

// connection details inherited from environment
const pool = new Pool({
    max: 1,
    min: 0,
    idleTimeoutMillis: 120000,
    connectionTimeoutMillis: 10000
});

export const handler: Handler = async (event, context) => {
  // https://github.com/brianc/node-postgres/issues/930#issuecomment-230362178
  context.callbackWaitsForEmptyEventLoop = false; // !important to reuse pool
  
  const client = await pool.connect();
    
  try {
    const result = await client.query("SELECT NOW()");
    return result;
  } finally {
    // https://github.com/brianc/node-postgres/issues/1180#issuecomment-270589769
    client.release(true);
  }
};