gruntjs – Uncaught SyntaxError: Identifier has already been declared

I am using grunt to uglify my Js code, but when I test my code in the browser I get:

Uncaught SyntaxError: Identifier has already been declared

Here is an example of the test I di:
files:

testA.js-

export const myData = {
  a: "hello",
  b: "Me",
};

testB.js-

import { myData } from "./testA.js";

const doSomething =()=>{
    console.log(myData);
}

doSomething();

uglify file:

test.min.js-

const myData = { a: "hello", b: "Me" };
import { myData } from "./testA.js";
const doSomething = () => {
    console.log(myData);
  },
  myData = (doSomething(), { a: "hello", b: "Me" });
import { myData } from "./testA.js";
const doSomething = () => {
  console.log(myData);
};
doSomething();
export { myData, myData };

As you can see myData is exported twice but the error line starts at line 2.
Is there a way to prevent grunt from creating duplicate identifiers to fix the problem?