Module Resolution Errors in Lambda with Typescript

Issues Dgraph
, ,
1

The documentation states that I can import types to write lambda scripts in Typescript. I have done this successfully but noticed Lambda only accepts UMD modules.

Typescript

import type * as dgraph from '@slash-graphql/lambda-types';

async function newEvent({ args, dql }: dgraph.GraphQLEventWithParent) {
  // lets give every new author a reputation of 3 by default
  const res = await dql.mutate(`{
    set {
        _:newAuth <Author.name> "${args.name}" .
        _:newAuth <Author.reputation> "3.0" .
        _:newAuth <dgraph.type> "Author" .
    }
  }`);
  return res.data?.uids.newAuth;
}

// eslint-disable-next-line no-restricted-globals
(self as any).addGraphQLResolvers({
  'Mutation.newAuthor': newEvent,
});

Transpiled Javascript (es2021) with CommonJS:

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
async function newEvent({ args, dql }) {
    // lets give every new author a reputation of 3 by default
    const res = await dql.mutate(`{
    set {
        _:newAuth <Author.name> "${args.name}" .
        _:newAuth <Author.reputation> "3.0" .
        _:newAuth <dgraph.type> "Author" .
    }
  }`);
    return res.data?.uids.newAuth;
}
// eslint-disable-next-line no-restricted-globals
self.addGraphQLResolvers({
    'Mutation.newAuthor': newEvent,
});

CommonJS Full error:

You have triggered an unhandledRejection, you may have forgotten to catch a Promise rejection:
evalmachine.<anonymous>:2
Object.defineProperty(exports, "__esModule", { value: true });
                      ^
ReferenceError: exports is not defined
    at evalmachine.<anonymous>:2:23
    at Script.runInContext (vm.js:144:12)
    at Object.evaluateScript (/app/src/evaluate-script.ts:90:10)
    at Object.scriptToExpress (/app/src/script-to-express.ts:17:18)
    at startServer (/app/src/index.ts:24:15)

Errors by Module Resolution Method

Reference: https://www.typescriptlang.org/tsconfig#module

Module Resolution Method Error
CommonJS ReferenceError: exports is not defined
UMD No error - works
AMD ReferenceError: define is not defined
System ReferenceError: System is not defined
esnext/es2020/es2015/es6 SyntaxError: Unexpected token 'export'

I think it would be useful to support CommonJS and es6/es2015 (and newer) module resolution methods in the lambda server, and at minimum document that only UMD is supported.