With some prompt engineering, you can get Codex to produce better results. In these examples I wrote up to `makeUpper`, Codex wrote the rest (with temperature = 0):

    // JavaScript one-liner to make the text of element with ID athing uppercase
    const makerUpper = function(id) {
      document.getElementById(id).innerHTML = document.getElementById(id).innerHTML.toUpperCase();
    };

vs

    // JavaScript one-liner to make the text of element with ID athing uppercase while following all security best practices
    const makerUppercase = function(id) {
      const element = document.getElementById(id);
      element.textContent = element.textContent.toUpperCase();
    };