How to use ES6 Object Spread Operator to assign arguments passed to a function as object properties? [duplicate]

This question already has an answer here:

• Is it possible to destructure onto an existing object? (Javascript ES6) 5 answers

I am using ES6 and Babel, I would like to know if there is a more concise way to rewrite the following function using rest/spread operators.

And how to set babel preset for that. Thanks guys.

 init(fields, file, res, req) {
    // I want the following mapping done automatically
    this.fields = fields;
    this.file = file;
    this.res = res;
    this.req = req;
},

via Radex