HTML Serializer

Requirements

• Export serializeHTML as named and default. Input is a string text node or { tag, attributes?, children? }; children are strings or element objects.
• Use two spaces per depth. Put opening tags, each child, and closing tags on separate lines. Empty non-void elements use <tag></tag> on one line. No trailing newline. Text inputs contain no newlines.
• Escape &, <, >, double quotes, and apostrophes in text and attribute values.
• Serialize attributes in Object.entries order. True is a bare boolean attribute; false, null, and undefined are omitted. Strings and numbers are double-quoted.
• Standard void tags render only an opening tag, without a slash or closing tag. Void nodes have no children. Tag and attribute names are valid lowercase names.
• Do not mutate input or use DOM serialization libraries. This is a JS/TS string-building exercise; no HTML or CSS files need to be authored. Cycles, raw HTML, comments, and script/style content are excluded.

Examples

Input: serializeHTML({ tag: "div", children: [{ tag: "p", children: ["Hello"] }] });
Output: <div>
  <p>
    Hello
  </p>
</div>