transformer: param decorator should be executed before metadata injections

[sapphi-red]

export class Foo {
  @methodDecorator
  method(@paramDecorator param: string): boolean {
    return !!param
  }
}

For the input above, the output of TypeScript (and SWC) runs the code related to paramDecorator before the code related to metadata. But the output of Oxc runs in the opposite order.

// TS output (omitted helpers)
export class Foo {
    method(param) {
        return !!param;
    }
}
__decorate([
    methodDecorator,
    __param(0, paramDecorator),
    __metadata("design:type", Function),
    __metadata("design:paramtypes", [String]),
    __metadata("design:returntype", Boolean)
], Foo.prototype, "method", null);

// Oxc output
export class Foo {
        method(param) {
                return !!param;
        }
}
_decorate([
        methodDecorator,
        _decorateMetadata("design:type", Function),
        _decorateMetadata("design:paramtypes", [String]),
        _decorateMetadata("design:returntype", Boolean),
        _decorateParam(0, paramDecorator)
], Foo.prototype, "method", null);

TS playground
SWC playground
reproduction using transform function exposed from rolldown

[Dunqing]

Just out of curiosity, does this break the actual case, or just break some tests due to run inconsistent execution? I've known this since I implemented it, and I took a look at metadata-reflect, but I didn't find that the decorators' order would have any effects

[overlookmotel]

Fixed in #13215.

[skovhus]

Thanks for the quick fix!

It broke booting up a node application that I tried bundling with rolldown. The application was using reflection to generate a GraphQl schema.

[sapphi-red]

_decorate runs functions passed in the reverse order and the paramDecorator was using the information injected by _decorateMetadata call.
To be specific, this @Arg decorator throwed an error at this line.
https://github.com/MichalLytek/type-graphql/blob/2611200a28177ac445f810e0d5982fbb8782c404/src/helpers/findType.ts#L64-L66