Syntax error when using --experimental-transform-types and a decorator

[damianobarbati]

Version

v22.7

Platform

MacOS

Subsystem

No response

What steps will reproduce the bug?

git clone git@github.com:damianobarbati/ts-repro.git
pnpm install
pnpm start

Is the command missing something obvious?

node --no-warnings --experimental-transform-types --watch ./src/index.ts

How often does it reproduce? Is there a required condition?

Always.

What is the expected behavior? Why is that the expected behavior?

Code should run.

What do you see instead?

$ pnpm start

file:///Users/damians/Desktop/ts-repro/src/Foe.ts:3
@log
^

SyntaxError: Invalid or unexpected token
at compileSourceTextModule (node:internal/modules/esm/utils:337:16)
at ModuleLoader.moduleStrategy (node:internal/modules/esm/translators:166:18)
at ModuleLoader. (node:internal/modules/esm/translators:540:10)
at callTranslator (node:internal/modules/esm/loader:436:14)
at ModuleLoader.moduleProvider (node:internal/modules/esm/loader:442:30)
at async ModuleJob._link (node:internal/modules/esm/module_job:106:19)

Node.js v22.7.0
Failed running './src/index.ts'

Additional information

Something very stupid must be missing here in how I run the command?

[damianobarbati]

@marco-ippolito is must be something trivial I'm missing, because nobody seems to have this problem and your tests are covering it in the last merge.

[marco-ippolito]

Please refer to the documentation: https://nodejs.org/docs/latest/api/typescript.html#typescript-features

Since Decorators are currently a TC39 Stage 3 proposal and will soon be supported by the JavaScript engine, they are not transformed and will result in a parser error. This is a temporary limitation and will be resolved in the future.

[damianobarbati]

@marco-ippolito do you have any news regarding v8 progress on decorators implementation? I can't find any info about it anywhere.

[B4nan]

We are hitting the same, but when executing JS, not TS. It feels quite weird to me that node 22 works fine when executing ES decorators but node 23 breaks because "they are stage 3 feature". Things work fine with --no-experimental-strip-types. I will try to provide a minimal repro and open a new issue, since its about executing JS so probably not so much of a wontfix material like this one. The repro we have now is basically using https://github.com/mikro-orm/guide and running npm i && npm run build && npm run start:prod. This compiles the ESM app via tsc and runs it via node.

[marco-ippolito]

Please open another issue