How to read the content of a JS file and insert it into CodeMirror

I’m using react-codemirror and I want to insert the content of a javascript file into the editor but since react-codemirror only receives text I don’t know how to implement this.

Suppose that I have a file


function findSequence(goal) {
  function find(start, history) {
    if (start == goal)
      return history;
    else if (start > goal)
      return null;
      return find(start + 5, "(" + history + " + 5)") ||
             find(start * 3, "(" + history + " * 3)");
  return find(1, "1");

How can I read this file and insert its content in the editor as a string but highlighted just like here?

This is outside of the scope of this library. In the browser you normally don’t have file system access, though there are exceptions and you can make HTTP requests.