luma-editor/lib/html.js

export function escapeChar(c) {
  if (c === "&") return "&";
  if (c === "<") return "&lt;";
  if (c === ">") return "&gt;";
  return c;
}

export function escapeHtml(s) {
  return s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
}