lambdaRunner.js

const {
  log,
  sendErr,
  sendOutput,
  installExceptionHandlers,
} = require('./lambda/util');

process.once(
  'message',
  async ({ module, handlerPath, handlerMethod, payload }) => {
    try {
      log.info('load', module);
      // eslint-disable-next-line
      const handlerModule = require(module);
      if (!handlerModule[handlerMethod]) {
        throw new Error(
          `Module : ${handlerPath} does not have export: ${handlerMethod}`,
        );
      }

      log.info('invoke', handlerMethod);
      const lambda = handlerModule[handlerMethod];
      const context = {};
      const lambdaResult = lambda(payload, context, (err, callbackResult) => {
        if (err) {
          sendErr(err);
        } else {
          sendOutput(callbackResult);
        }
      });
      if (lambdaResult instanceof Promise) {
        sendOutput(await lambdaResult);
      }
    } catch (err) {
      log.error(err);
      sendErr(err);
    }
  },
);

installExceptionHandlers();