Typescript装饰器欺骗2个参数，如何编译？

Question

I've been reading up more about decorators in typescript and ES7. And I tried this simple code:

function decorator(...args) {
    console.log(args);
}

//@decorator
class foo {
    constructor() {}

    @decorator
    method() {}
}

let bar = new foo();
bar.method();

This is what I get in the console:

$ npm install -g typescript@2.1.15
$ npm install -g @types/node
$ tsc --experimentalDecorators file.ts
$ node file.js
[ foo { method: [Function] }, 'method' ]

Only two arguments.

However if I execute this in the typescript playground, I have this result

Array[3]

Where Arra[0] and Array[2] are Objects and Array[1] is a string.

How this is possible? Furthermore, how should I properly compile typescript with the experimental decorators?

My best regards...

Answer 1

Solved. According to https://www.typescriptlang.org/docs/handbook/compiler-options.html the default target is ES3.

Setting the target to ES5 solves the problem:

$ tsc --experimentalDecorators -t 'es5' t.ts && node t.js
[ foo { method: [Function] },
  'method',
  { value: [Function],
    writable: true,
    enumerable: true,
    configurable: true } ]

Regards.