Function inspectElement

browse/src/cdp-inspector.ts:229–489

(
  page: Page,
  selector: string,
  options?: { includeUA?: boolean }
)

 * Inspect an element via CDP, returning full CSS cascade data.
 */
export async function inspectElement(
  page: Page,
  selector: string,
  options?: { includeUA?: boolean }
): Promise<InspectorResult> {
  const session = await getOrCreateSession(page);

  // Get document root
  const { root } = await session.send('DOM.getDocument', { depth: 0 });

  // Query for the element
  let nodeId: number;
  try {
    const result = await session.send('DOM.querySelector', {
      nodeId: root.nodeId,
      selector,
    });
    nodeId = result.nodeId;
    if (!nodeId) throw new Error(`Element not found: ${selector}`);
  } catch (err: any) {
    throw new Error(`Element not found: ${selector} — ${err.message}`);
  }

  // Get element attributes
  const { node } = await session.send('DOM.describeNode', { nodeId, depth: 0 });
  const tagName = (node.localName || node.nodeName || '').toLowerCase();
  const attrPairs = node.attributes || [];
  const attributes: Record<string, string> = {};
  for (let i = 0; i < attrPairs.length; i += 2) {
    attributes[attrPairs[i]] = attrPairs[i + 1];
  }
  const id = attributes.id || null;
  const classes = attributes.class ? attributes.class.split(/\s+/).filter(Boolean) : [];

  // Get box model
  let boxModel = {
    content: { x: 0, y: 0, width: 0, height: 0 },
    padding: { top: 0, right: 0, bottom: 0, left: 0 },
    border: { top: 0, right: 0, bottom: 0, left: 0 },
    margin: { top: 0, right: 0, bottom: 0, left: 0 },
  };

  try {
    const boxData = await session.send('DOM.getBoxModel', { nodeId });
    const model = boxData.model;

    // Content quad: [x1,y1, x2,y2, x3,y3, x4,y4]
    const content = model.content;
    const padding = model.padding;
    const border = model.border;
    const margin = model.margin;

    const contentX = content[0];
    const contentY = content[1];
    const contentWidth = content[2] - content[0];
    const contentHeight = content[5] - content[1];

    boxModel = {