src/index.mjs

/**
 * Copyright 2022 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * This module is the bootstrap entrypoint. It establishes the top-level event
 * listeners and loads the user's code.
 */

const RAPIDClient = require('./RAPIDClient.js');
const Runtime = require('./Runtime.js');
const UserFunction = require('./UserFunction.js');
const Errors = require('./Errors.js');
const BeforeExitListener = require('./BeforeExitListener.js');
const LogPatch = require('./LogPatch');

export async function run(appRootOrHandler, handler = '') {
  LogPatch.patchConsole();
  const client = new RAPIDClient(process.env.AWS_LAMBDA_RUNTIME_API);

  let errorCallbacks = {
    uncaughtException: (error) => {
      client.postInitError(error, () => process.exit(129));
    },
    unhandledRejection: (error) => {
      client.postInitError(error, () => process.exit(128));
    },
  };

  process.on('uncaughtException', (error) => {
    LogPatch.structuredConsole.logError('Uncaught Exception', error);
    errorCallbacks.uncaughtException(error);
  });

  process.on('unhandledRejection', (reason, promise) => {
    let error = new Errors.UnhandledPromiseRejection(reason, promise);
    LogPatch.structuredConsole.logError('Unhandled Promise Rejection', error);
    errorCallbacks.unhandledRejection(error);
  });

  BeforeExitListener.reset();
  process.on('beforeExit', BeforeExitListener.invoke);

  const handlerFunc = UserFunction.isHandlerFunction(appRootOrHandler)
    ? appRootOrHandler
    : await UserFunction.load(appRootOrHandler, handler);

  const metadata = UserFunction.getHandlerMetadata(handlerFunc);
  new Runtime(
    client,
    handlerFunc,
    metadata,
    errorCallbacks,
  ).scheduleIteration();
}