Table of Contents

Requirements

• Export tableOfContents as named and default. Return a new tree of { id, text, level, children } nodes for h1 through h6 descendants in document order.
• Use existing non-empty heading IDs. IDs are unique. Skip headings without an ID entirely, including for nesting.
• Trim heading textContent, including text from nested inline elements. Keep the actual numeric heading level and an empty children array for leaves.
• Attach each heading to the nearest preceding included heading with a smaller level. If none exists it is a root node. Equal levels are siblings; skipped levels do not create placeholder nodes.
• Exclude the root itself, ignore other elements, and never mutate the DOM or heading IDs. Native DOM queries are allowed.
• This function produces a data tree, not a rendered UI. Tests supply the HTML document; users write JS/TS only.

Examples

Input: // Headings: h2#intro, h4#detail, h2#next
tableOfContents(root);
Output: [{ id: "intro", text: "Intro", level: 2, children: [{ id: "detail", text: "Detail", level: 4, children: [] }] }, { id: "next", text: "Next", level: 2, children: [] }]