Function setupReverseSearch

lib/internal/repl/utils.js:524–754

(repl)

}

function setupReverseSearch(repl) {
  // Simple terminals can't use reverse search.
  if (process.env.TERM === 'dumb') {
    return { reverseSearch() { return false; } };
  }

  const alreadyMatched = new SafeSet();
  const labels = {
    r: 'bck-i-search: ',
    s: 'fwd-i-search: ',
  };
  let isInReverseSearch = false;
  let historyIndex = -1;
  let input = '';
  let cursor = -1;
  let dir = 'r';
  let lastMatch = -1;
  let lastCursor = -1;
  let promptPos;

  function checkAndSetDirectionKey(keyName) {
    if (!labels[keyName]) {
      return false;
    }
    if (dir !== keyName) {
      // Reset the already matched set in case the direction is changed. That
      // way it's possible to find those entries again.
      alreadyMatched.clear();
      dir = keyName;
    }
    return true;
  }

  function goToNextHistoryIndex() {
    // Ignore this entry for further searches and continue to the next
    // history entry.
    alreadyMatched.add(repl.history[historyIndex]);
    historyIndex += dir === 'r' ? 1 : -1;
    cursor = -1;
  }

  function search() {
    // Just print an empty line in case the user removed the search parameter.
    if (input === '') {
      print(repl.line, `${labels[dir]}_`);
      return;
    }
    // Fix the bounds in case the direction has changed in the meanwhile.
    if (dir === 'r') {
      if (historyIndex < 0) {
        historyIndex = 0;
      }
    } else if (historyIndex >= repl.history.length) {
      historyIndex = repl.history.length - 1;
    }
    // Check the history entries until a match is found.
    while (historyIndex >= 0 && historyIndex < repl.history.length) {
      let entry = repl.history[historyIndex];