ToolBox/src/utils/comparator/html.js

export function escapeHtml(text) {
  return String(text)
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&#39;')
}

export function highlightDiff(text, diffRanges) {
  if (!diffRanges || diffRanges.length === 0) {
    return escapeHtml(text)
  }

  let result = ''
  let lastIndex = 0

  diffRanges.forEach(range => {
    if (range.start > lastIndex) {
      result += escapeHtml(text.substring(lastIndex, range.start))
    }
    result += `<span class="diff-highlight">${escapeHtml(text.substring(range.start, range.end))}</span>`
    lastIndex = range.end
  })

  if (lastIndex < text.length) {
    result += escapeHtml(text.substring(lastIndex))
  }

  return result
}