[Question] How to use a custom typescript package?

[LisBerndt]

Hello!

To execute some preparations we use a helper-package, written in typescript.
The sources of this package work fine when they are part of the source code of my playwright app. - I can import it, so that I can use it as a fixture e.g.
My idea was now to separate that package onto a verdaccio server to make it reusable for other playwright-projects. But here I am in tremendous trouble now.
The package itself works as expected, but after installing it and trying my playwright-app to run with it, I always get:

JavaScript files must end with .mjs to use import.

Interesting - I do not use any js-files.
Nevertheless, my naive approach here was, "ok... then I provide the files also with .mjs-extension." - But this fails as well.
I have read related topics, but I am not able to get it work.

That is my tsconfig.json

{
  "compilerOptions": {
    "strict": false,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "target":"ES2022",
    "moduleResolution": "Node"
  }
}

That is my config.json

{
  "name": "@private/resource_provider",
  "version": "1.0.12",
  "description": "",
  "main": "/resource_provider/resource_provider",
  "directories": {
    "test": "tests"
  },
  "devDependencies": {
    "@types/node": "^17.0.35",
    "gts": "^3.1.0",
    "tslib": "^2.4.0",
    "typescript": "^4.6.4"
  },
  "dependencies": {
    "node-fetch": "^2.6.7",
    "ts-node": "^10.7.0"
  },
  "scripts": {
    "test": "npx ts-node tests/test.ts"
  },
}

I confess, I am not that experienced with that config-stuff. - What is the best practice to integrate custom typescript packages?

PS: Using .js-extension as recommended here gives: Error: Cannot find module [...].js

[pavelfeldman]

This does not give me a good idea on what you are trying to do - your question seems to be not about Playwright, but about creating a custom typescript package. Node can't execute TypeScript, so there is no such thing as a "custom typescript package". You would need to compile your module into JS, preferably to CJS for better interoperability. I think I have a better idea on the linked issue, so we can continue this conversation there.