Initializer provides no value for this binding element and the binding element has no default value

引起错误的TypeScript代码：

test(){
    const a = () => ({ a , b = 2 } = {}): number => 11;
  }

该编译错误的解决方法1

test(){
    const a = () => ({ a , b = 2 }:any = {}): number => 11;
  }

解法2

test(){
    const a = () => ({ a = 1, b = 2 } = {}): number => 11;
  }

解法3

 test(){
    const fun = () => ({ a , b } = { a: 1, b: 2}): number => 11;
  }

参考：stackoverflow.com/questions/5…