Function findRootCompositionEl

packages/core/src/runtime/init.ts:139–148

()

  // array-normalization + data-start defaults below pick the same root the
  // closure-based `resolveRootCompositionElement` does on multi-comp pages.
  const findRootCompositionEl = (): HTMLElement | null => {
    const explicitRoot = document.querySelector('[data-composition-id][data-root="true"]');
    if (explicitRoot instanceof HTMLElement) return explicitRoot;
    const nodes = Array.from(document.querySelectorAll("[data-composition-id]")) as HTMLElement[];
    return (
      nodes.find((node) => !node.parentElement?.closest("[data-composition-id]")) ??
      nodes[0] ??
      null
    );
  };

  // Agents often write `window.__timelines = [tl]` (array) instead of the
  // keyed-by-composition-id object the runtime expects. Normalize at init so