ES6: Create Strings using Template Literals problem

I have this code:

const result = {
  success: ["max-length", "no-amd", "prefer-arrow-functions"],
  failure: ["no-var", "var-on-top", "linebreak"],
  skipped: ["id-blacklist", "no-dup-keys"]
};
function makeList(arr) {
  "use strict";

  // change code below this line
  //const resultDisplayArray = null;
  let resultDisplayArray = `<li class="text-warning">${arr[0]}</li> <li class="text-warning">${arr[1]}</li> <li class="text-warning">${arr[2]}</li>`;
  
  // change code above this line

  return resultDisplayArray;
}
/**
 * makeList(result.failure) should return:
 * [ `<li class="text-warning">no-var</li>`,
 *   `<li class="text-warning">var-on-top</li>`, 
 *   `<li class="text-warning">linebreak</li>` ]
 **/
const resultDisplayArray = makeList(result.failure);

I get errors:

resultDisplayArray is a list containing result failure messages.

makeList(…).every is not a function

Any ideas?

OK, no need to answer this one. I solved it.