Function isLikelyExternalSourceNode

packages/core/src/hydration/error_handling.ts:443–455

* Checks if a given RNode is likely to have been added by a third-party script * or browser extension, by checking whether Angular has any knowledge of it * via patched data. Nodes created and managed by Angular will always have * patched data attached to them.

(rNode: RNode)

 * patched data attached to them.
 */
function isLikelyExternalSourceNode(rNode: RNode): boolean {
  const node = rNode as Node;
  if (node.nodeType !== Node.ELEMENT_NODE) {
    return false;
  }
  // If Angular has patched this node, it was created within Angular's context.
  if (readPatchedData(node as HTMLElement)) {
    return false;
  }
  // No patched data means Angular has no record of this node —
  // it was likely injected by a third-party script or browser extension.
  return true;
}

/**
 * An attribute related note for hydration errors