SyntaxError: Invalid or unexpected token when running `npm start:prod`

[hanshuebner]

I had an issue with my version of the guide created from following the ❤️ excellent ❤️ "Getting Started" documentation, exposing itself as:

% pnpm start:prod

> @mikro-orm/getting-started@6.0.0 start:prod /Users/hans/Development/privat/mikro-orm-guide
> NODE_ENV=production node dist/server.js

[info] MikroORM version: 6.4.6
[discovery] ORM entity discovery started, using ReflectMetadataProvider
[discovery] - processing 6 files
SyntaxError: Invalid or unexpected token
    at compileSourceTextModule (node:internal/modules/esm/utils:338:16)
    at ModuleLoader.moduleStrategy (node:internal/modules/esm/translators:106:18)
    at ModuleLoader.<anonymous> (node:internal/modules/esm/translators:549:10)
    at #translate (node:internal/modules/esm/loader:470:12)
    at ModuleLoader.loadAndTranslate (node:internal/modules/esm/loader:517:27)
    at async ModuleJob._link (node:internal/modules/esm/module_job:115:19)
(node:46890) ExperimentalWarning: Type Stripping is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)

I wanted to see whether the repository version of the sample application has the same issue, but before I could even run it, I ahd to update its dependencies because the committed version would not build on macOS 15.3. I made the changes as in this PR, and with those, the error above occurs in the repository version as well. Any ideas?

[B4nan]

Well, I am using latest macos, things work just fine on my end 🤷

SyntaxError: Invalid or unexpected token

this is not about any dependency, that is more like you running TS via node. the warning on a later line kinda confirms that.

[B4nan]

note that the guide uses legacy decorators, you wont be able to execute that via node's TS support (at least i think so), i would expect that to be the problem. either way, what you say here is not reproducible, you must have changed something in the ORM config or package.json, or its some pnpm quirk

[hanshuebner]

Thank you for getting back! I've fixed the problem that caused the original dependencies not to build and then retried from scratch using your repository unchanged with npm. The problem remains:

plasma 1407_% git clone git@github.com:mikro-orm/guide
Cloning into 'guide'...
remote: Enumerating objects: 80, done.
remote: Counting objects: 100% (39/39), done.
remote: Compressing objects: 100% (33/33), done.
remote: Total 80 (delta 10), reused 6 (delta 6), pack-reused 41 (from 1)
Receiving objects: 100% (80/80), 132.29 KiB | 728.00 KiB/s, done.
Resolving deltas: 100% (15/15), done.
plasma 1408_% cd guide/
plasma 1409_% npm i
npm warn deprecated inflight@1.0.6: This module is not supported, and leaks memory. Do not use it. Check out lru-cache if you want a good and tested way to coalesce async requests by a key value, which is much more comprehensive and powerful.
npm warn deprecated @npmcli/move-file@1.1.2: This functionality has been moved to @npmcli/fs
npm warn deprecated npmlog@6.0.2: This package is no longer supported.
npm warn deprecated rimraf@3.0.2: Rimraf versions prior to v4 are no longer supported
npm warn deprecated are-we-there-yet@3.0.1: This package is no longer supported.
npm warn deprecated glob@7.2.3: Glob versions prior to v9 are no longer supported
npm warn deprecated gauge@4.0.4: This package is no longer supported.

added 376 packages, and audited 377 packages in 20s

47 packages are looking for funding
  run `npm fund` for details

6 vulnerabilities (2 low, 3 moderate, 1 high)

To address all issues, run:
  npm audit fix

Run `npm audit` for details.
plasma 1410_% npm run build

> @mikro-orm/getting-started@6.0.0 build
> tsc && npx mikro-orm-esm cache:generate --combined

[discovery] ORM entity discovery started, using TsMorphMetadataProvider
[discovery] - processing 6 files
[discovery] - processing entity ArticleListing (/private/tmp/guide/dist/modules/article/article-listing.entity.js)
[discovery] - processing entity Article (/private/tmp/guide/dist/modules/article/article.entity.js)
[discovery] - processing entity Comment (/private/tmp/guide/dist/modules/article/comment.entity.js)
[discovery] - processing entity Tag (/private/tmp/guide/dist/modules/article/tag.entity.js)
[discovery] - processing entity BaseEntity (/private/tmp/guide/dist/modules/common/base.entity.js)
[discovery] - processing entity Social (/private/tmp/guide/dist/modules/user/user.entity.js)
[discovery] - processing entity User (/private/tmp/guide/dist/modules/user/user.entity.js)
[discovery] - entity discovery finished, found 8 entities, took 671 ms
Combined JS metadata cache was successfully generated to /private/tmp/guide/temp/metadata.json
plasma 1411_% npm run start:prod

> @mikro-orm/getting-started@6.0.0 start:prod
> NODE_ENV=production node dist/server.js

[info] MikroORM version: 6.4.0
[discovery] ORM entity discovery started, using ReflectMetadataProvider
[discovery] - processing 6 files
SyntaxError: Invalid or unexpected token
    at compileSourceTextModule (node:internal/modules/esm/utils:338:16)
    at ModuleLoader.moduleStrategy (node:internal/modules/esm/translators:106:18)
    at ModuleLoader.<anonymous> (node:internal/modules/esm/translators:549:10)
    at #translate (node:internal/modules/esm/loader:470:12)
    at ModuleLoader.loadAndTranslate (node:internal/modules/esm/loader:517:27)
    at async ModuleJob._link (node:internal/modules/esm/module_job:115:19)
(node:61566) ExperimentalWarning: Type Stripping is an experimental feature and might change at any time
(Use `node --trace-warnings ...` to show where the warning was created)

You're probably not wrong about saying that I'm using node with type stripping, but it seems that the start:prod correctly uses the transpiled files in dist/, so that should not be the issue.

[B4nan]

ok, now i see the same with node 23, it is indeed something with the type stripping which wasn't enabled in v22

this works fine: node --no-experimental-strip-types dist/server.js

[B4nan]

still i dont see anything i should be fixing here, sounds more like something to report to nodejs. the fact that they don't even print the problematic statement or its location really sucks 🙃

[hanshuebner]

Ah, works for me as well. Maybe I'll just downgrade to node 22 (again).

[hanshuebner]

Thank you very much for your quick help! I am really impressed by MikroORM and the getting started guide in particular!

[B4nan]

seeing this: nodejs/node#54901

they likely dont support decorators at all, not legacy, neither ESM, since they are not stable yet (stage 3)

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.

https://nodejs.org/docs/latest/api/typescript.html#typescript-features

it still feels like a bug to me that the same code works with node 22 but breaks with 23, we are not executing TS here...

[B4nan]

mikro-orm/mikro-orm#6488 should resolve this