Function InterfaceConstructor

lib/internal/readline/interface.js:160–356

(input, output, completer, terminal)

const kAddNewLineOnTTY = Symbol('_addNewLineOnTTY');

function InterfaceConstructor(input, output, completer, terminal) {
  this[kSawReturnAt] = 0;
  // TODO(BridgeAR): Document this property. The name is not ideal, so we
  // might want to expose an alias and document that instead.
  this.isCompletionEnabled = true;
  this[kSawKeyPress] = false;
  this[kPreviousKey] = null;
  this.escapeCodeTimeout = ESCAPE_CODE_TIMEOUT;
  this.tabSize = 8;

  FunctionPrototypeCall(EventEmitter, this);

  let crlfDelay;
  let prompt = '> ';
  let signal;

  if (input?.input) {
    // An options object was given
    output = input.output;
    completer = input.completer;
    terminal = input.terminal;
    signal = input.signal;

    // It is possible to configure the history through the input object
    const historySize = input.historySize;
    const history = input.history;
    const removeHistoryDuplicates = input.removeHistoryDuplicates;

    if (input.tabSize !== undefined) {
      validateUint32(input.tabSize, 'tabSize', true);
      this.tabSize = input.tabSize;
    }
    if (input.prompt !== undefined) {
      prompt = input.prompt;
    }
    if (input.escapeCodeTimeout !== undefined) {
      if (NumberIsFinite(input.escapeCodeTimeout)) {
        this.escapeCodeTimeout = input.escapeCodeTimeout;
      } else {
        throw new ERR_INVALID_ARG_VALUE(
          'input.escapeCodeTimeout',
          this.escapeCodeTimeout,
        );
      }
    }

    if (signal) {
      validateAbortSignal(signal, 'options.signal');
    }

    crlfDelay = input.crlfDelay;
    input = input.input;

    input.size = historySize;
    input.history = history;
    input.removeHistoryDuplicates = removeHistoryDuplicates;
  }