@babel/plugin-transform-duplicate-keys

    1. var x = { a: 5, ["a"]: 6 };
    2. var y = {
    3.   get a() {},
    5.   ["a"]: 3,
    1. {
    3. }
    1. require("@babel/core").transformSync("code", {
    2.   plugins: ["@babel/plugin-transform-duplicate-keys"],