8.1.0 breaks named imports when using ESM

[BenSjoberg]

Is there an existing issue for this?

• I have searched the existing issues

Current behavior

8.1.0 must seems to have changed something with exports, which affects projects using pure ESM. After updating, my application fails to launch with the following message:

import { Controller, Get, Header } from '@nestjs/common';
         ^^^^^^^^^^
SyntaxError: Named export 'Controller' not found. The requested module '@nestjs/common' is a CommonJS module, which may not support all module.exports as named exports.
CommonJS modules can always be imported via the default export, for example using:

Downgrading to 8.0.11 resolves the issue. A workaround without downgrading is to do something like:

import nestcommon from '@nestjs/common';
const import { Controller, Get, Header } = nestcommon;

But this is pretty clumsy.

Our project transpiles TypeScript to ESM, instead of to CommonJS, since some of our dependencies have moved to pure ESM without a CommonJS fallback.

Minimum reproduction code

https://github.com/BenSjoberg/nest-esm-import-issue-example

Steps to reproduce

• Install @nestjs/common 8.0.11
• Create a file called test.mjs with the content import { Controller } from '@nestjs/common';
  • Alternatively, named the file test.js and set "type": "module" in package.json
• Run node test.mjs - it should work.
• Upgrade @nestjs/common to 8.1.0, it will fail with the error I described.

The sample repo I linked shows the issue in a working nest.js project. The initial commit (bfcd0c99) works because it's pinned to Nest 8.0.x, the latest commit doesn't work because I updated to 8.1.0.

Expected behavior

Named imports should work from pure ESM as they did in 8.0.x.

Package

• I don't know. Or some 3rd-party package
• @nestjs/common
• @nestjs/core
• @nestjs/microservices
• @nestjs/platform-express
• @nestjs/platform-fastify
• @nestjs/platform-socket.io
• @nestjs/platform-ws
• @nestjs/testing
• @nestjs/websockets
• Other (see below)

Other package

No response

NestJS version

No response

Packages versions

• @nestjs/cli: 8.1.2
• @nestjs/common: 8.1.0
• @nestjs/core: 8.1.0
• @nestjs/platform-express: 8.1.0
• @nestjs/schematics: 8.0.3
• @nestjs/testing: 8.1.0

Node.js version

16.11.1

In which operating systems have you tested?

• macOS
• Windows
• Linux

Other

No response

[BenSjoberg]

I did a little more digging, and it seems like this is related to the upgrade to TypeScript 4.4. TypeScript changed how function calls work in emitted code in some circumstances, which is causing named exports to stop working in ESM. This likely affects more than just Nest. microsoft/TypeScript#45813

Would it be possible to downgrade TS to 4.3 until they're able to fix this?

[kamilmysliwiec]

Thanks for investigating this issue! Temporarily reverted & fixed in 8.1.1

[BenSjoberg]

Thanks so much! 😃

[vadistic]

@kamilmysliwiec FYI same thing is still broken for @nestjs/graphql nestjs/graphql#1843

[BenSjoberg]

This appears to have broken again in 8.3.0 due to 329b083.

Would it be possible keep TypeScript at 4.3.x until 4.6 is released? Based on my testing in the dev release of TypeScript, the problem that causes this will be fixed in 4.6.

[sionzee]

@BenSjoberg I think this deserves a new issue otherwise it won't get fixed.

[kamilmysliwiec]

Fixed in 8.3.1

[huan]

I run into this issue today with @nestjs/[email protected]:

┌ [email protected]:~/git/wechaty/friday/src/core/statuspage/sagas [19:31:42] tty:[3] jobs:[0]
└ {nestjs} $ ./statuspage.saga.spec.ts 
file:///home/huan/git/wechaty/friday/src/wechaty-repository/wechaty.repository.ts:2
import { Injectable, OnModuleDestroy, OnModuleInit } from '@nestjs/common';
                     ^^^^^^^^^^^^^^^
SyntaxError: Named export 'OnModuleDestroy' not found. The requested module '@nestjs/common' is a CommonJS module, which may not support all module.exports as named exports.
CommonJS modules can always be imported via the default export, for example using:

import pkg from '@nestjs/common';
const { Injectable, OnModuleDestroy, OnModuleInit } = pkg;

    at ModuleJob._instantiate (node:internal/modules/esm/module_job:124:21)
    at async ModuleJob.run (node:internal/modules/esm/module_job:181:5)
    at async Promise.all (index 0)
    at async ESMLoader.import (node:internal/modules/esm/loader:281:24)
    at async loadESM (node:internal/process/esm_loader:88:5)
    at async handleMainPromise (node:internal/modules/run_main:65:12)

$ npm ls @nestjs/common
[email protected] /home/huan/git/wechaty/friday
├── @nestjs/[email protected]
├─┬ @nestjs/[email protected]
│ └── @nestjs/[email protected] deduped
├─┬ @nestjs/[email protected]
│ └── @nestjs/[email protected] deduped
├─┬ @nestjs/[email protected]
│ └── @nestjs/[email protected] deduped
├─┬ @nestjs/[email protected]
│ └── @nestjs/[email protected] deduped
├─┬ @nestjs/[email protected]
│ └── @nestjs/[email protected] deduped
└─┬ @nestjs/[email protected]
  └── @nestjs/[email protected] deduped

┌ [email protected]:~/git/wechaty/friday/src/core/statuspage/sagas [19:33:40] tty:[3] jobs:[0]
└ {nestjs} $ npm ls typescript
[email protected] /home/huan/git/wechaty/friday
├─┬ @chatie/[email protected]
│ └─┬ @typescript-eslint/[email protected]
│   └─┬ [email protected]
│     └── [email protected] deduped
├─┬ @chatie/[email protected]
│ ├─┬ [email protected]
│ │ └── [email protected] deduped
│ ├─┬ [email protected]
│ │ └─┬ [email protected]
│ │   └── [email protected] deduped
│ └── [email protected]
├─┬ @nestjs/[email protected]
│ ├─┬ [email protected]
│ │ └── [email protected] deduped
│ └── [email protected] deduped
└─┬ @nestjs/[email protected]
  └── [email protected] deduped

┌ [email protected]:~/git/wechaty/friday/src/core/statuspage/sagas [19:37:40] tty:[3] jobs:[0]
└ {nestjs} $ node --version
v16.13.2

Reproduce repo:

https://github.com/wechaty/friday/tree/25c04016497a7f3af44e6563b5c88e0f8a8ffe25

[sionzee]

@huan
The bug was again fixed in 8.3.1 and it works without issues.

That must be an issue on your side, if you generate a new project, you will notice it works out of the box.

Looks like you are using SWC, have you make a right configuration for SWC to be running in es mode? The default tool for test is ts-node at nestjs, in case of swc you must enable decorators + proper settings for latest ES.

[huan]

@sionzee Thanks for the quick reply!

I'm working on it and trying to figure out the problem right now.

My case is very strange: all the code works without any problem this afternoon; after I do an rm -fr node_modules/ && npm i, then this error message jumped out.

For example, you can see that version 1.13.8 has passed the CI tests, which means it has no this problem at that time:

The PR is at:

• NextJS-ify Friday BOT wechaty/friday#112

My SWC works in the past days. I guess my problem is related to the node_modules file change.

I will update here when I got any updates.

[huan]

Update

it seems that @sionzee is right, my issue is related to swc.

I have created an issue on my repo for continuing tracking my problem.

• SyntaxError: Named export 'OnModuleDestroy' not found. The requested module '@nestjs/common' is a CommonJS module, which may not support all module.exports as named exports. wechaty/friday#114

Thank you very much!

[Toilal]

I hit this issue, and I can confirm it's fixed by upgrading.