Vitest error: PostHog seems to be an ES Module but shipped in a CommonJS package

[MathiasWP]

They explicitly asked me to make an issue asking you to ship the file in .mjs extension or add "type": "module" in their package.json, so here it is.

[JayaKrishnaNamburu]

This can be parsed in three different ways.

1

Marking the whole package as es-module. Which means, adding type: module inside the package.json file. Which effectively lets bundlers know they are using a es module.

2

Adding .mjs extension to the files, so when loaded they are handled as es-modules.

3

This is one of the most used ones, that is to add exports field to the packages. jspm.io does it automatically to all the packages. It takes into consideration of the main and then the files keys in the package.json.
You can see the exports field that is pre-populated
https://ga.jspm.io/npm:[email protected]/package.json

"exports": {
    ".": {
      "module": "./dist/module.js",
      "default": "./dist/main.js"
    },
    "./react": {
      "module": "./react/dist/esm/index.js",
      "default": "./react/dist/umd/index.js"
    },
    "./react/dist/esm/index.js": "./react/dist/esm/index.js",
    "./dist/main.js": "./dist/main.js",
    "./dist/module.js": "./dist/module.js",
    "./react/dist/umd/index.js": "./react/dist/umd/index.js",
    "./dist/main.js!cjs": "./dist/main.js",
    "./react/dist/umd/index.js!cjs": "./react/dist/umd/index.js"
  }

But doing this on your own in the package.json will be the best possible way. I looked into it, i just have some doubts. The package exposes main and module. Happy to help in creating one 👍