Space added before decorated method parameter

[mjbvz]

From microsoft/vscode#39554

TypeScript Version: 2.7.0-dev.20171203

Code

class Test {
    constructor(@foo props: any) {
    }
}

Run format

Expected behavior:
No change

Actual behavior:
Space added:

class Test {
    constructor( @foo props: any) {
    }
}

[Trace  - 11:54:15 AM] Response received: format (92). Request took 4 ms. Success: true 
Result: [
    {
        "start": {
            "line": 2,
            "offset": 17
        },
        "end": {
            "line": 2,
            "offset": 17
        },
        "newText": " "
    }
]