alpha-numeric-list generation yields empty Array within React Native app but works in chrome console

alpha-numeric-list-troubles.js

    let alphabet = [...Array(26).keys()]
      .map(x => x + 65)
      .map(x => String.fromCharCode(x));
    
    console.log(alphabet);
    
    // [0, 1, ..., 9, A, B, C, ..., Z]
    // let alphanumericCharacters = _.concat(_.range(10), alphabet);
    let alphanumericCharacters = [...Array(10).keys()]
      .concat(alphabet);

    console.log(alphanumericCharacters);

    // alphanumericCharacters = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 'A', 'B', 'C', 'D', 'E', 'F'];

    // I endend up using lodash library to do the same thing that ES6 JS should let me do