ESM import of @azure/monitor-opentelemetry fails

[alexgagnon]

• Package Name: @azure/monitor-opentelemetry
• Package Version: 1.2.0
• Operating system: Windows
• [x] nodejs
  • version: 20.10
• [ ] browser
  • name/version: N/A
• [x] typescript
  • version: 5.3.3
• Is the bug related to documentation in
  • [ ] README.md
  • [ ] source code documentation
  • [ ] SDK API docs on https://docs.microsoft.com

Describe the bug In a project using ESM ("type": "module") it seems like @azure/monitor-opentelemetry incorrectly references the underlying @opentelemetry/resource library, giving the following error:

var resources = require('@opentelemetry/resources');
                ^

Error [ERR_REQUIRE_ESM]: require() of ES Module C:\Users\...\node_modules\@opentelemetry\resources\build\src\index.js from C:\Users\...\node_modules\@azure\monitor-opentelemetry\dist\index.js not supported.
C:\Users\...\node_modules\@opentelemetry\resources\build\src\index.js is treated as an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which declares all .js files in that package scope as ES modules.
Instead either rename C:\Users\...\node_modules\@opentelemetry\resources\build\src\index.js to end in .cjs, change the requiring code to use dynamic import() which is available in all CommonJS modules, or change "type": "module" to "type": "commonjs" in C:\Users\...\node_modules\@opentelemetry\resources\package.json to treat all .js files as CommonJS (using .mjs for all ES modules instead).

    at Object.<anonymous> (C:\Users\...\node_modules\@azure\monitor-opentelemetry\dist\index.js:8:17) {
  code: 'ERR_REQUIRE_ESM'
}

To Reproduce Steps to reproduce the behavior:

1. Create a simple node project with typescript and @azure/monitor-opentelemetry
2. Import the useAzureMonitor function

import { useAzureMonitor } from '@azure/monitor-opentelemetry';
useAzureMonitor();

Expected behavior It works and starts sending data to the insights resource indicated in the APPLICATIONINSIGHTS_CONNECTION_STRING env var

Additional context

Here's my tsconfig.json file if that helps

{
  "compilerOptions": {
    "module": "NodeNext",
    "target": "ES2020",
    "lib": ["ES2020"],
    "skipLibCheck": true,
    "outDir": "dist",
    // "esModuleInterop": true,
    // "allowJs": true,
    "allowSyntheticDefaultImports": true,
    "resolveJsonModule": true,
    "isolatedModules": true,

    /* Linting */
    "strict": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noFallthroughCasesInSwitch": true,
  },
  "include": ["src"],
}

[JacksonWeber]

@alexgagnon I've recreated an application using the reproduction steps detailed in your issue (including the tsconfig.json) and I don't appear to have any errors thrown. Could you give this a try with the latest version of the @azure/monitor-opentelemetry package?