Import not working or unknown file extension".ts"

[jcroma]

Hello there, I am trying to migrate on of our library to typescript. Decided to use ts-node since our tests are working on it.
Changed all files to .ts then import as node_modules library.
When I'm trying to use "type": "module" in package.json of library I'm getting error:

(node:1836) ExperimentalWarning: The ESM module loader is experimental.
TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for [...path]

When I remove type field from package.json and launch then I get:

import * as program from 'commander';
^^^^^^

SyntaxError: Cannot use import statement outside a module

So non of most solution worked for me.

My tsconfig.json:

    "ts-node": {
        "compilerOptions": {
            "module": "CommonJS",
            "esModuleInterop": true,
            "declaration": true,
        }
    }

execution of library:

"ts-node ./node_modules/qtest-integration/lib/qtest-main --rename"

node version: v12.18.2
typescript: "version": "3.9.6"

Any ideas what I'm doing wrong ?

[RossiniMaximo]

Hello , i was wondering if you fixed it because i'm having the same issue and i can't figure out what it is .

[RossiniMaximo]

It was "type": "module" giving the error , i don't know why because i put it there because it was supposedly required

[jcroma]

I was able to solve this issue. For my case it was problem with omitting node_modules due to ts-node basic behaviour.
Fix for that was:
add empty ignore in tsconfig.json:

    "ts-node": {
        "ignore": []
    }

and also by cli command: ts-node --skip-ignore ./node_modules/your_package