Function mergeAttributes

packages/extension/utils/component.ts:421–595

(code: string, attrs: Record<string, string>)

}

export function mergeAttributes(code: string, attrs: Record<string, string>): string {
  if (!code || !Object.keys(attrs).length) return code

  let i = 0
  // Skip leading whitespace
  while (i < code.length && /\s/.test(code[i])) i++

  if (code[i] !== '<') return code
  i++

  // Scan Tag Name
  while (i < code.length && /[a-zA-Z0-9\-_:.]/.test(code[i])) i++
  const tagNameEnd = i

  const existingAttrs = new Map<
    string,
    { nameStart: number; valueStart: number; valueEnd: number; quote: string }
  >()

  while (i < code.length) {
    // Skip whitespace
    while (i < code.length && /\s/.test(code[i])) i++

    if (i >= code.length) break

    // Check for end of tag
    if (code[i] === '>') {
      break
    }
    if (code[i] === '/' && code[i + 1] === '>') {
      break
    }

    // Attribute Name
    const attrNameStart = i
    while (i < code.length && /[^=\s/>]/.test(code[i])) i++
    const attrName = code.slice(attrNameStart, i)

    // Skip whitespace after name
    while (i < code.length && /\s/.test(code[i])) i++

    // Check for equals
    if (code[i] === '=') {
      i++ // skip =
      // Skip whitespace after =
      while (i < code.length && /\s/.test(code[i])) i++

      // Attribute Value
      let quote = ''
      let valueStart = i
      let valueEnd

      if (code[i] === '"' || code[i] === "'") {
        quote = code[i]
        i++
        valueStart = i
        while (i < code.length && code[i] !== quote) {
          if (code[i] === '\\') i++ // skip escaped char