ts-node cannot run mixed ESM/CJS project about ts-node HOT 2 OPEN

I wanted to create a new issue targeting the same problem but then I found this one so I am commenting here. See this stackblitz.

// main.cts
(async () => {
  const dep = await import('./dep.mjs');
  console.log(dep);
})()

// dep.mts
export const dep = 'dependency';

I expected ts-node main.cts and tsc && node dist/main.cjs to behave the same but I get this error

Cannot find module '[..]/dep.mjs' imported from [..]/main.cts

What do I need to do to make this run with ts-node?
Edit: ts-node-esm main.cts works for me.

from ts-node.

It appears this broke in Node 18.19 and versions released since have the issue.

There have been multiple issues tracking facets of it, in multiple repositories (node, typescript, ts-node, esbuild, tsx among others), over the last few months, but no resolution. In #2094 the common strategy is to work around the issue - either downgrade Node to 18.18, or use whatever alternative works in your scenario, for example tsx (in which the same issue is half-fixed). None of those workarounds represent an actual fix.

The scenario is very simple: it happens in mixed CJS/ESM repositories, using TS in development with tooling that isn't always new, and inevitably some dependencies that don't support a global switch to modules in package.json. Node and some tooling (tsx) defaults to CJS in the absence of type=module in package.json, and so import-s are now broken, especially in an .mjs file importing .ts, e.g. import { named } from './tsfile' (treated as CJS). The CJS-compatible import('./file').then(...) pattern works in the forced CJS context. Or you could rename your .ts file to .mts and hope that the ESM system wakes up.

I'd love if ts-node had updates about this, but I'm already having to test with alternatives. 🤷

from ts-node.