Calculate Accuracy Score in Google Forms

GoogleFormsCalculateScore.js

var GoogleFormsTool = {
    getScore() {
        let correct = document.getElementsByClassName('freebirdFormviewerViewItemsItemCorrect'),
            incorrect = document.getElementsByClassName('freebirdFormviewerViewItemsItemIncorrect'),
            total = correct.length + incorrect.length,
            incorrectDisplay = [],
            yIncrement = 0;

        for (let k of incorrect) {
            k.parentElement.id = "gfcs_incorrect_" + yIncrement++;
            incorrectDisplay.push({
                id: k.parentElement.id,
                text: k.innerText.trim()
            });
        }
        
        if (total === 0) {
        	return false;
        }

        return {
            correctCount: correct.length,
            incorrectCount: incorrect.length,
            incorrectDisplay: incorrectDisplay,
            totalCount: total,
            score: Number(((correct.length / total) * 100).toFixed(2))
        };
    },
    displayScore() {
        let score = this.getScore();
        
        if (!score) {
        	return;
        }
        
        document.querySelectorAll('[role="listitem"]')[0].innerHTML += `<div class="freebirdFormviewerViewItemsItemItem freebirdFormviewerViewItemsTextTextItem">
        <h1 style="margin-top:0%">Score: ${score.score.toFixed(0)}</h1>
        <hr>
            <ul>
                <li>Correct: <b>${score.correctCount}</b></li>
                <li>Incorrect: <b>${score.incorrectCount}</b></li>
                <li>Question Count: <b>${score.totalCount}</b></li>
                <li>Score: <b>${score.score}</b></li>
            </ul>
        <hr>
        <h3>Incorrect Answers</h2>
        <ul>
        ${score.incorrectDisplay.map(i => `<li><a href="#${i.id}">${i.text}</a></li>`).join('')}
        </ul>
        </div>`;
    },
    run() {
        if (window.location.pathname.split('/').pop() === 'viewscore') {
            setTimeout(() => {
                this.displayScore();
            }, 1000);
        }
    }
}
GoogleFormsTool.run();

Here's a screenshot:

It will only show on the view score page after 1 second.