解决方法
花括号被解释为
block statement,而不是对象文字.您不能使用左大括号开始表达式语句.
规范说明：
NOTE An ExpressionStatement cannot start with an opening curly brace
because that might make it ambiguous with a Block. Also,an
ExpressionStatement cannot start with thefunctionkeyword because
that might make it ambiguous with a FunctionDeclaration.
