Kumite

isUnique=s=>new Set(s).size==s.length

// Since Node 10, we're using Mocha.
// You can use `chai` for assertions.
const chai = require("chai");
const assert = chai.assert;
// Uncomment the following line to disable truncating failure messages for deep equals, do:
// chai.config.truncateThreshold = 0;
// Since Node 12, we no longer include assertions from our deprecated custom test framework by default.
// Uncomment the following to use the old assertions:
 const Test = require("@codewars/test-compat");

describe("Solution", function() {
  it("should return true for strings without repetition", function() {
    Test.assertEquals(isUnique('gino'), true);
    Test.assertEquals(isUnique('glhf'), true);
    // assert.strictEqual(1 + 1, 2);
  });
    it("should return false for strings with repetition", function() {
    Test.assertEquals(isUnique('gg'), false);
    Test.assertEquals(isUnique('phillip'), false);
    // assert.strictEqual(1 + 1, 2);
  });
});