Resolution of this package as ESM is broken due to missing package.json in esm output

[ajaffie]

NodeJS is resolving this package as CommonJS because a package.json file with "type": "module" is missing from the esm output.
Here is the error I am getting:

SyntaxError: Named export 'LabelFilter' not found. The requested module '@azure/app-configuration-provider' 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 '@azure/app-configuration-provider';
  const { LabelFilter, load } = pkg;

      at ModuleJob._instantiate (node:internal/modules/esm/module_job:220:21)
      at async ModuleJob.run (node:internal/modules/esm/module_job:321:5)
      at async onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:644:26)
      at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:117:5)

  Node.js v22.17.1

If I add a package.json to the dist/esm folder with the contents below, then the error is fixed:

{
  "type": "module"
}

I copied this from the @azure/app-configuration package's esm folder.

[zhiyuanliang-ms]

Hey, @ajaffie

Sorry for the inconvenience.

I was trying to reproduce the issue. But I cannot reproduce the same error message that you got.

Could you please share your code and your setup with me to help me reproduce the issue?

The code below can work on my side.

import { LabelFilter, load } from '@azure/app-configuration-provider';

const appConfig = await load(connectionString, {
    selectors: [
        {
            keyFilter: "*",
            labelFilter: LabelFilter.Null
        }
    ]
});

console.log(appConfig.get("Message"));

This is my package.json and tsconfig.json

{
  "name": "typescript-playground",
  "version": "1.0.0",
  "type": "module",
  "scripts": {
    "build": "tsc",
    "start": "node dist/index.js"
  },
  "devDependencies": {
    "@types/node": "^25.1.0",
    "typescript": "^5.6.0"
  },
  "dependencies": {
    "@azure/app-configuration-provider": "2.3.1"
  }
}

{
  "compilerOptions": {
    "target": "ES2019",
    "module": "nodenext",
    "moduleResolution": "nodenext",
    "outDir": "dist",
    "strict": true,
    "esModuleInterop": true
  },
  "include": ["src"]
}

I am using Node.js 22.22.1.

---

NodeJS is resolving this package as CommonJS because a package.json file with "type": "module" is missing from the esm output.

We are use conditional exports (which following Azure SDK's practice)

So the node.js resolution or bundlers should be able to find the correct entry point.

---

But I do find that if I use default export (like the suggestion from the error message you posted)

import pkg from '@azure/app-configuration-provider';
const { LabelFilter, load } = pkg;

const appConfig = await load(connectionString, {
    selectors: [
        {
            keyFilter: "*",
            labelFilter: LabelFilter.Null
        }
    ]
});

console.log(appConfig.get("Message"));

I will get the following error:

import pkg from '@azure/app-configuration-provider';
       ^^^
SyntaxError: The requested module '@azure/app-configuration-provider' does not provide an export named 'default'
    at ModuleJob._instantiate (node:internal/modules/esm/module_job:226:21)
    at async ModuleJob.run (node:internal/modules/esm/module_job:335:5)
    at async onImport.tracePromise.__proto__ (node:internal/modules/esm/loader:665:26)
    at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:117:5)

Node.js v22.21.1

This is because we don't have default export in the esm artifact.