Function lexAcceptedHmrDeps

packages/vite/src/node/server/hmr.ts:1000–1102

(
  code: string,
  start: number,
  urls: Set<{ url: string; start: number; end: number }>,
)

 * @returns selfAccepts
 */
export function lexAcceptedHmrDeps(
  code: string,
  start: number,
  urls: Set<{ url: string; start: number; end: number }>,
): boolean {
  let state: LexerState = LexerState.inCall
  // the state can only be 2 levels deep so no need for a stack
  let prevState: LexerState = LexerState.inCall
  let currentDep: string = ''

  function addDep(index: number) {
    urls.add({
      url: currentDep,
      start: index - currentDep.length - 1,
      end: index + 1,
    })
    currentDep = ''
  }

  for (let i = start; i < code.length; i++) {
    const char = code.charAt(i)
    switch (state) {
      case LexerState.inCall:
      case LexerState.inArray:
        if (char === `'`) {
          prevState = state
          state = LexerState.inSingleQuoteString
        } else if (char === `"`) {
          prevState = state
          state = LexerState.inDoubleQuoteString
        } else if (char === '`') {
          prevState = state
          state = LexerState.inTemplateString
        } else if (whitespaceRE.test(char)) {
          continue
        } else {
          if (state === LexerState.inCall) {
            if (char === `[`) {
              state = LexerState.inArray
            } else {
              // reaching here means the first arg is neither a string literal
              // nor an Array literal (direct callback) or there is no arg
              // in both case this indicates a self-accepting module
              return true // done
            }
          } else {
            if (char === `]`) {
              return false // done
            } else if (char === ',') {
              continue
            } else {
              error(i)
            }
          }
        }
        break
      case LexerState.inSingleQuoteString:
        if (char === `'`) {