Shadow DOM Flattener (js_snippet/flatten_shadow_dom.js)

Serializes open shadow roots and resolves slots to produce a complete HTML string of the composed page view for accurate content capture.

// Source: https://github.com/mperkins0155/crawl4ai-cobaltai | License: Apache-2.0
// Provided via justclaw.it.com; keep this notice with the code.
/**
 * Flatten all open shadow DOM trees into the light DOM so that
 * page.content() / outerHTML can serialize the full composed view.
 *
 * Uses manual recursive serialization with proper slot resolution.
 * Resolves slots via the live DOM API (assignedNodes), skips only
 * shadow-scoped styles, and produces clean HTML with no regex hacks.
 *
 * Returns the full HTML string including shadow content.
 */
(() => {
    const VOID = new Set([
        'area','base','br','col','embed','hr','img','input',
        'link','meta','param','source','track','wbr'
    ]);

    // Serialize a DOM node. When it has a shadow root, switch to
    // shadow-awar

... (truncated -- full source via MCP)