Decorators after export looks terrible. I'm still unhappy with that decision (or non-decision). The following is from a test for stage-3 decorators support (TypeScript needs to support both, even if we will error on decorators before in JS :

// @filename: file2.ts

@dec1
@dec2
export class D {
}

@dec1
@dec2
export default class E {
}

// @filename: file3.ts

export
@dec1
@dec2
class F {
}

export default
@dec1
@dec2
class G {
}