Local execution of TypeScript Actors broken in Node 20

[wodow]

Minimal reproduction:

❯ apify create
? Name of your new actor: test-ts-actor
? Choose the programming language of your new actor: TypeScript
? Choose a template for your new actor. Detailed information about the template will be shown in the
next step. Start with TypeScript
? Do you want to install the following template?
Start with TypeScript:
A simple TypeScript example of core Actor and Apify SDK features. It reads and validates user input
with schema, computes a result and saves it to storage. Install template
Run: npm install
added 149 packages, and audited 150 packages in 14s
31 packages are looking for funding
run `npm fund` for details
found 0 vulnerabilities
Success: Actor 'test-ts-actor' was created. To run it, run "cd test-ts-actor" and "apify run".

Then, doing what it asks:

❯ apify run
Run: npm start

> [email protected] start
> npm run start:dev


> [email protected] start:dev
> ts-node-esm -T src/main.ts

TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for <SNIP>/test-ts-actor/src/main.ts
    at new NodeError (node:internal/errors:399:5)
    at Object.getFileProtocolModuleFormat [as file:] (node:internal/modules/esm/get_format:99:9)
    at defaultGetFormat (node:internal/modules/esm/get_format:139:38)
    at defaultLoad (node:internal/modules/esm/load:83:20)
    at nextLoad (node:internal/modules/esm/hooks:735:28)
    at load (<SNIP>/test-ts-actor/node_modules/ts-node/dist/child/child-loader.js:19:122)
    at nextLoad (node:internal/modules/esm/hooks:735:28)
    at Hooks.load (node:internal/modules/esm/hooks:380:26)
    at MessagePort.handleMessage (node:internal/modules/esm/worker:165:24)
    at [nodejs.internal.kHybridDispatch] (node:internal/event_target:762:20) {
  code: 'ERR_UNKNOWN_FILE_EXTENSION'
}
Error: npm exited with code 1

This is on latest MacOS with Node 20 installed from Brew/Homebrew.

Downgrading to Node 18 (latest LTS) resolves the problem.

[wodow]

A recent SO post suggested this issue thread: TypeStrong/ts-node#1997

[B4nan]

Sounds like a ts-node issue, not really about the CLI (that just runs npm start for you). I guess you get the same problem when you do npm start or run the command that it wraps (so ts-node-esm -T src/main.ts)?

Does node --loader ts-node/esm src/main.ts work? That's what people suggest in the issue you linked.

[B4nan]

Closing as there was no response, from my experience with this problem from other projects, the node --loader will do the job.

edit: this is actually already resolved in the template, and the ts-node-esm did the job