Can't import helmet package when using ESM

[basicdays]

Hey all,

I'm trying to start a new Node Express project and want to try to get it working with ESM. I've followed did all the ESM jest.config.ts settings that were recommended. The project can successfully be transpiled by TypeScript and can be ran. However, when I attempt to import from the helmet package, jest is failing with the following:

 FAIL  src/app.test.ts
  ● Test suite failed to run

    src/app.ts:32:10 - error TS2349: This expression is not callable.
      Type 'typeof import(".../node_modules/helmet/index")' has no call signatures.

    32   helmet.default({

From what I'm able to sleuth so far on why helmet is different, is that the package structure is as follows:

node_modules/helmet
├── index.cjs
├── index.d.cts
├── index.d.mts
├── index.mjs
└── package.json

With it's package.json import settings as:

{
	"exports": {
		"import": "./index.mjs",
		"require": "./index.cjs"
	},
	"main": "./index.cjs",
	"types": "./index.d.cts"
}

I've built a mini-app on a public repo here that recreates the issue: https://github.com/basicdays/jest-ts-node

Running npm install && npm test will reproduce the error.

[sylver]

hey @basicdays,
I just encountered the problem. How did you fix it ?