emitDecoratorMetadata is not working properly!

[JawadAhbab]

What version of Bun is running?

0.8.1+16b4bf341acc0f4804f0b6bdf5298c180cd00366

What platform is your computer?

Darwin 22.6.0 arm64 arm

What steps can reproduce the bug?

import 'reflect-metadata'

const Decor = () => {
  return (target: any, name: string) => {
    const reflect = Reflect.getMetadata('design:type', target, name)
    console.log(reflect) // undefined
  }
}

class MyClass {
  @Decor() prop: string
}

tsconfig.json

{
  "compilerOptions": {
    "target": "ES2021",
    "module": "ES2022",
    "moduleResolution": "node",
    "types": ["bun-types"],
    "esModuleInterop": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "forceConsistentCasingInFileNames": true,
    "strict": false,
    "skipLibCheck": true
  }
}

Here reflect is undefined. It means design:type not reflected but in tsconfig emitDecoratorMetadata is true. (I guess) emitDecoratorMetadata is not working.

What is the expected behavior?

No response

What do you see instead?

No response

Additional information

No response

[sirenkovladd]

I guess it is related https://github.com/oven-sh/bun/tree/dylan/emit-decorator-metadata

[JawadAhbab]

I guess it is related https://github.com/oven-sh/bun/tree/dylan/emit-decorator-metadata

Any update about this branch?

[daniel-nagy]

I have the same issue. I was able to use a plugin to transpile files with decorators using TypeScript, which worked, but then ran into this issue #4689.

For reference I'm currently using TypeGraphQL which relies on decorator metadata.

[Zikoat]

This is blocking TypeGraphQL and TypeORM for us.

@daniel-nagy Do you have the plugin you are talking about? Or is this something you cooked up?

[daniel-nagy]

@Zikoat I'm using a fork of https://github.com/thomaschaaf/esbuild-plugin-tsc to support esm, see thomaschaaf/esbuild-plugin-tsc#20. Also see #5111. You would need to modify the plugin to always return the file content.

[ecattez]

I guess it is related https://github.com/oven-sh/bun/tree/dylan/emit-decorator-metadata

Any update about this branch?

Branch seems to have been merged on main: 4a1573e
https://bun.sh/blog/bun-v1.0.3

[octet-stream]

Bun v1.0.3 released with emitDecoratorMetadata support: https://github.com/oven-sh/bun/releases/tag/bun-v1.0.3

Just tried it MikroORM and it seem to work (I can clearly see metadata in compiled code and corresponding types in database schema).

[JawadAhbab]

Fixed in Bun v1.0.3 🎉🎉🎉

[Bielik20]

I am not sure I should be writing it here or on #5000
but --tsconfig-override doesn't work with that (or at all).

I have a monorepo setting with a command to run from the root of the repository (it does not have tsconfig.json file there).

bun apps/customer-sls/bun-bundle.ts --tsconfig-override ./apps/customer-sls/tsconfig.app.json

bun-bundle.ts is just a file that executes Bun.build. For decorators metadata to work I need to create tsconfig.json at the repository root. Pointing with --tsconfig-override has no effect.