Run results for: Traverse function vs NodeIterator vs TreeWalker

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36

Browser: Chrome 80

Operating system: Linux

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
Traverse function	29770.9 Ops/sec
NodeIterator with filter function	5166.8 Ops/sec
NodeIterator with filter param	249815.6 Ops/sec
TreeWalker with filter function	21062.0 Ops/sec
TreeWalker with filter param	237526.5 Ops/sec

Script Preparation code:

// language=HTML
const html = `
    <!-- article out start -->
    <article>
        <!-- article in start -->
        <h1>Lorem ipsum</h1>
        <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cumque, nostrum.</p>
        <!-- article in end -->
    </article>
    <!-- article out end -->

    <!-- article out start -->
    <article>
        <!-- article in start -->
        <h1>Lorem ipsum</h1>
        <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cumque, nostrum.</p>
        <!-- article in end -->
    </article>
    <!-- article out end -->

    <!-- article out start -->
    <article>
        <!-- article in start -->
        <h1>Lorem ipsum</h1>
        <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cumque, nostrum.</p>
        <!-- article in end -->
    </article>
    <!-- article out end -->
`;
const template = document.createElement('template');
template.innerHTML = html;

window.testTemplate = template;

window.testTraverse = function traverse(node, use) {
    if (!node) return;

    use(node);
    traverse(node.firstChild, use);
    traverse(node.nextSibling, use);
}

Tests:

Traverse function
const comments = []; testTraverse(testTemplate.content.firstChild, node => { if (node.nodeType === Node.COMMENT_NODE) { comments.push(node); } });
NodeIterator with filter function
const nodeIterator = document.createNodeIterator( testTemplate.content, NodeFilter.SHOW_ALL, { acceptNode(node) { if (node.nodeType === Node.COMMENT_NODE) { return NodeFilter.FILTER_ACCEPT; } return NodeFilter.FILTER_REJECT; } } ); const comments = []; while (nodeIterator.nextNode()) { comments.push(nodeIterator.currentNode); }
NodeIterator with filter param
const nodeIterator = document.createNodeIterator( testTemplate.content, NodeFilter.SHOW_COMMENT ); const comments = []; while (nodeIterator.nextNode()) { comments.push(nodeIterator.currentNode); }
TreeWalker with filter function
const treeWalker = document.createTreeWalker( testTemplate.content, NodeFilter.SHOW_ALL, { acceptNode(node) { if (node.nodeType === Node.COMMENT_NODE) { return NodeFilter.FILTER_ACCEPT; } return NodeFilter.FILTER_REJECT; } } ); const comments = []; while (treeWalker.nextNode()) { comments.push(treeWalker.currentNode); }
TreeWalker with filter param
const treeWalker = document.createTreeWalker( testTemplate.content, NodeFilter.SHOW_COMMENT ); const comments = []; while (treeWalker.nextNode()) { comments.push(treeWalker.currentNode); }

Run results for: Traverse function vs NodeIterator vs TreeWalker

Let's compare the speed of 3 different ways to traverse the DOM.

Traverse function

NodeIterator with filter function

NodeIterator with filter param

TreeWalker with filter function

TreeWalker with filter param