diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
new file mode 100644
index 00000000000000..e50172f5628ccc
--- /dev/null
+++ b/lib/internal/readline/interface.js
@@ -0,0 +1,1261 @@
+'use strict';
+
+const {
+  ArrayFrom,
+  ArrayPrototypeFilter,
+  ArrayPrototypeIndexOf,
+  ArrayPrototypeJoin,
+  ArrayPrototypeMap,
+  ArrayPrototypePop,
+  ArrayPrototypeReverse,
+  ArrayPrototypeSplice,
+  ArrayPrototypeUnshift,
+  DateNow,
+  FunctionPrototypeCall,
+  MathCeil,
+  MathFloor,
+  MathMax,
+  MathMaxApply,
+  NumberIsFinite,
+  NumberIsNaN,
+  ObjectSetPrototypeOf,
+  RegExpPrototypeTest,
+  StringPrototypeCodePointAt,
+  StringPrototypeEndsWith,
+  StringPrototypeMatch,
+  StringPrototypeRepeat,
+  StringPrototypeReplace,
+  StringPrototypeSlice,
+  StringPrototypeSplit,
+  StringPrototypeStartsWith,
+  StringPrototypeTrim,
+  Symbol,
+  SymbolAsyncIterator,
+  SafeStringIterator,
+} = primordials;
+
+const { codes } = require('internal/errors');
+
+const { ERR_INVALID_ARG_VALUE } = codes;
+const {
+  validateAbortSignal,
+  validateArray,
+  validateString,
+  validateUint32,
+} = require('internal/validators');
+const {
+  inspect,
+  getStringWidth,
+  stripVTControlCharacters,
+} = require('internal/util/inspect');
+const EventEmitter = require('events');
+const {
+  charLengthAt,
+  charLengthLeft,
+  commonPrefix,
+  kSubstringSearch,
+} = require('internal/readline/utils');
+let emitKeypressEvents;
+const {
+  clearScreenDown,
+  cursorTo,
+  moveCursor,
+} = require('internal/readline/callbacks');
+
+const { StringDecoder } = require('string_decoder');
+
+// Lazy load Readable for startup performance.
+let Readable;
+
+const kHistorySize = 30;
+const kMincrlfDelay = 100;
+// \r\n, \n, or \r followed by something other than \n
+const lineEnding = /\r?\n|\r(?!\n)/;
+
+const kLineObjectStream = Symbol('line object stream');
+const kQuestionCancel = Symbol('kQuestionCancel');
+
+// GNU readline library - keyseq-timeout is 500ms (default)
+const ESCAPE_CODE_TIMEOUT = 500;
+
+const kAddHistory = Symbol('_addHistory');
+const kDecoder = Symbol('_decoder');
+const kDeleteLeft = Symbol('_deleteLeft');
+const kDeleteLineLeft = Symbol('_deleteLineLeft');
+const kDeleteLineRight = Symbol('_deleteLineRight');
+const kDeleteRight = Symbol('_deleteRight');
+const kDeleteWordLeft = Symbol('_deleteWordLeft');
+const kDeleteWordRight = Symbol('_deleteWordRight');
+const kGetDisplayPos = Symbol('_getDisplayPos');
+const kHistoryNext = Symbol('_historyNext');
+const kHistoryPrev = Symbol('_historyPrev');
+const kInsertString = Symbol('_insertString');
+const kLine = Symbol('_line');
+const kLine_buffer = Symbol('_line_buffer');
+const kMoveCursor = Symbol('_moveCursor');
+const kNormalWrite = Symbol('_normalWrite');
+const kOldPrompt = Symbol('_oldPrompt');
+const kOnLine = Symbol('_onLine');
+const kPreviousKey = Symbol('_previousKey');
+const kPrompt = Symbol('_prompt');
+const kQuestionCallback = Symbol('_questionCallback');
+const kRefreshLine = Symbol('_refreshLine');
+const kSawKeyPress = Symbol('_sawKeyPress');
+const kSawReturnAt = Symbol('_sawReturnAt');
+const kSetRawMode = Symbol('_setRawMode');
+const kTabComplete = Symbol('_tabComplete');
+const kTabCompleter = Symbol('_tabCompleter');
+const kTtyWrite = Symbol('_ttyWrite');
+const kWordLeft = Symbol('_wordLeft');
+const kWordRight = Symbol('_wordRight');
+const kWriteToOutput = Symbol('_writeToOutput');
+
+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 history;
+  let historySize;
+  let removeHistoryDuplicates = false;
+  let crlfDelay;
+  let prompt = '> ';
+  let signal;
+
+  if (input?.input) {
+    // An options object was given
+    output = input.output;
+    completer = input.completer;
+    terminal = input.terminal;
+    history = input.history;
+    historySize = input.historySize;
+    signal = input.signal;
+    if (input.tabSize !== undefined) {
+      validateUint32(input.tabSize, 'tabSize', true);
+      this.tabSize = input.tabSize;
+    }
+    removeHistoryDuplicates = input.removeHistoryDuplicates;
+    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;
+  }
+
+  if (completer !== undefined && typeof completer !== 'function') {
+    throw new ERR_INVALID_ARG_VALUE('completer', completer);
+  }
+
+  if (history === undefined) {
+    history = [];
+  } else {
+    validateArray(history, 'history');
+  }
+
+  if (historySize === undefined) {
+    historySize = kHistorySize;
+  }
+
+  if (
+    typeof historySize !== 'number' ||
+      NumberIsNaN(historySize) ||
+      historySize < 0
+  ) {
+    throw new ERR_INVALID_ARG_VALUE.RangeError('historySize', historySize);
+  }
+
+  // Backwards compat; check the isTTY prop of the output stream
+  //  when `terminal` was not specified
+  if (terminal === undefined && !(output === null || output === undefined)) {
+    terminal = !!output.isTTY;
+  }
+
+  const self = this;
+
+  this.line = '';
+  this[kSubstringSearch] = null;
+  this.output = output;
+  this.input = input;
+  this.history = history;
+  this.historySize = historySize;
+  this.removeHistoryDuplicates = !!removeHistoryDuplicates;
+  this.crlfDelay = crlfDelay ?
+    MathMax(kMincrlfDelay, crlfDelay) :
+    kMincrlfDelay;
+  this.completer = completer;
+
+  this.setPrompt(prompt);
+
+  this.terminal = !!terminal;
+
+
+  function onerror(err) {
+    self.emit('error', err);
+  }
+
+  function ondata(data) {
+    self[kNormalWrite](data);
+  }
+
+  function onend() {
+    if (
+      typeof self[kLine_buffer] === 'string' &&
+        self[kLine_buffer].length > 0
+    ) {
+      self.emit('line', self[kLine_buffer]);
+    }
+    self.close();
+  }
+
+  function ontermend() {
+    if (typeof self.line === 'string' && self.line.length > 0) {
+      self.emit('line', self.line);
+    }
+    self.close();
+  }
+
+  function onkeypress(s, key) {
+    self[kTtyWrite](s, key);
+    if (key && key.sequence) {
+      // If the key.sequence is half of a surrogate pair
+      // (>= 0xd800 and <= 0xdfff), refresh the line so
+      // the character is displayed appropriately.
+      const ch = StringPrototypeCodePointAt(key.sequence, 0);
+      if (ch >= 0xd800 && ch <= 0xdfff) self[kRefreshLine]();
+    }
+  }
+
+  function onresize() {
+    self[kRefreshLine]();
+  }
+
+  this[kLineObjectStream] = undefined;
+
+  input.on('error', onerror);
+
+  if (!this.terminal) {
+    function onSelfCloseWithoutTerminal() {
+      input.removeListener('data', ondata);
+      input.removeListener('error', onerror);
+      input.removeListener('end', onend);
+    }
+
+    input.on('data', ondata);
+    input.on('end', onend);
+    self.once('close', onSelfCloseWithoutTerminal);
+    this[kDecoder] = new StringDecoder('utf8');
+  } else {
+    function onSelfCloseWithTerminal() {
+      input.removeListener('keypress', onkeypress);
+      input.removeListener('error', onerror);
+      input.removeListener('end', ontermend);
+      if (output !== null && output !== undefined) {
+        output.removeListener('resize', onresize);
+      }
+    }
+
+    emitKeypressEvents ??= require('internal/readline/emitKeypressEvents');
+    emitKeypressEvents(input, this);
+
+    // `input` usually refers to stdin
+    input.on('keypress', onkeypress);
+    input.on('end', ontermend);
+
+    this[kSetRawMode](true);
+    this.terminal = true;
+
+    // Cursor position on the line.
+    this.cursor = 0;
+
+    this.historyIndex = -1;
+
+    if (output !== null && output !== undefined)
+      output.on('resize', onresize);
+
+    self.once('close', onSelfCloseWithTerminal);
+  }
+
+  if (signal) {
+    const onAborted = () => self.close();
+    if (signal.aborted) {
+      process.nextTick(onAborted);
+    } else {
+      signal.addEventListener('abort', onAborted, { once: true });
+      self.once('close', () => signal.removeEventListener('abort', onAborted));
+    }
+  }
+
+  // Current line
+  this.line = '';
+
+  input.resume();
+}
+
+ObjectSetPrototypeOf(InterfaceConstructor.prototype, EventEmitter.prototype);
+ObjectSetPrototypeOf(InterfaceConstructor, EventEmitter);
+
+class Interface extends InterfaceConstructor {
+  // eslint-disable-next-line no-useless-constructor
+  constructor(input, output, completer, terminal) {
+    super(input, output, completer, terminal);
+  }
+  get columns() {
+    if (this.output && this.output.columns) return this.output.columns;
+    return Infinity;
+  }
+
+  /**
+   * Sets the prompt written to the output.
+   * @param {string} prompt
+   * @returns {void}
+   */
+  setPrompt(prompt) {
+    this[kPrompt] = prompt;
+  }
+
+  /**
+   * Returns the current prompt used by `rl.prompt()`.
+   * @returns {string}
+   */
+  getPrompt() {
+    return this[kPrompt];
+  }
+
+  [kSetRawMode](mode) {
+    const wasInRawMode = this.input.isRaw;
+
+    if (typeof this.input.setRawMode === 'function') {
+      this.input.setRawMode(mode);
+    }
+
+    return wasInRawMode;
+  }
+
+  /**
+   * Writes the configured `prompt` to a new line in `output`.
+   * @param {boolean} [preserveCursor]
+   * @returns {void}
+   */
+  prompt(preserveCursor) {
+    if (this.paused) this.resume();
+    if (this.terminal && process.env.TERM !== 'dumb') {
+      if (!preserveCursor) this.cursor = 0;
+      this[kRefreshLine]();
+    } else {
+      this[kWriteToOutput](this[kPrompt]);
+    }
+  }
+
+  question(query, cb) {
+    if (this[kQuestionCallback]) {
+      this.prompt();
+    } else {
+      this[kOldPrompt] = this[kPrompt];
+      this.setPrompt(query);
+      this[kQuestionCallback] = cb;
+      this.prompt();
+    }
+  }
+
+  [kOnLine](line) {
+    if (this[kQuestionCallback]) {
+      const cb = this[kQuestionCallback];
+      this[kQuestionCallback] = null;
+      this.setPrompt(this[kOldPrompt]);
+      cb(line);
+    } else {
+      this.emit('line', line);
+    }
+  }
+
+  [kQuestionCancel]() {
+    if (this[kQuestionCallback]) {
+      this[kQuestionCallback] = null;
+      this.setPrompt(this[kOldPrompt]);
+      this.clearLine();
+    }
+  }
+
+  [kWriteToOutput](stringToWrite) {
+    validateString(stringToWrite, 'stringToWrite');
+
+    if (this.output !== null && this.output !== undefined) {
+      this.output.write(stringToWrite);
+    }
+  }
+
+  [kAddHistory]() {
+    if (this.line.length === 0) return '';
+
+    // If the history is disabled then return the line
+    if (this.historySize === 0) return this.line;
+
+    // If the trimmed line is empty then return the line
+    if (StringPrototypeTrim(this.line).length === 0) return this.line;
+
+    if (this.history.length === 0 || this.history[0] !== this.line) {
+      if (this.removeHistoryDuplicates) {
+        // Remove older history line if identical to new one
+        const dupIndex = ArrayPrototypeIndexOf(this.history, this.line);
+        if (dupIndex !== -1) ArrayPrototypeSplice(this.history, dupIndex, 1);
+      }
+
+      ArrayPrototypeUnshift(this.history, this.line);
+
+      // Only store so many
+      if (this.history.length > this.historySize)
+        ArrayPrototypePop(this.history);
+    }
+
+    this.historyIndex = -1;
+
+    // The listener could change the history object, possibly
+    // to remove the last added entry if it is sensitive and should
+    // not be persisted in the history, like a password
+    const line = this.history[0];
+
+    // Emit history event to notify listeners of update
+    this.emit('history', this.history);
+
+    return line;
+  }
+
+  [kRefreshLine]() {
+    // line length
+    const line = this[kPrompt] + this.line;
+    const dispPos = this[kGetDisplayPos](line);
+    const lineCols = dispPos.cols;
+    const lineRows = dispPos.rows;
+
+    // cursor position
+    const cursorPos = this.getCursorPos();
+
+    // First move to the bottom of the current line, based on cursor pos
+    const prevRows = this.prevRows || 0;
+    if (prevRows > 0) {
+      moveCursor(this.output, 0, -prevRows);
+    }
+
+    // Cursor to left edge.
+    cursorTo(this.output, 0);
+    // erase data
+    clearScreenDown(this.output);
+
+    // Write the prompt and the current buffer content.
+    this[kWriteToOutput](line);
+
+    // Force terminal to allocate a new line
+    if (lineCols === 0) {
+      this[kWriteToOutput](' ');
+    }
+
+    // Move cursor to original position.
+    cursorTo(this.output, cursorPos.cols);
+
+    const diff = lineRows - cursorPos.rows;
+    if (diff > 0) {
+      moveCursor(this.output, 0, -diff);
+    }
+
+    this.prevRows = cursorPos.rows;
+  }
+
+  /**
+   * Closes the `readline.Interface` instance.
+   * @returns {void}
+   */
+  close() {
+    if (this.closed) return;
+    this.pause();
+    if (this.terminal) {
+      this[kSetRawMode](false);
+    }
+    this.closed = true;
+    this.emit('close');
+  }
+
+  /**
+   * Pauses the `input` stream.
+   * @returns {void | Interface}
+   */
+  pause() {
+    if (this.paused) return;
+    this.input.pause();
+    this.paused = true;
+    this.emit('pause');
+    return this;
+  }
+
+  /**
+   * Resumes the `input` stream if paused.
+   * @returns {void | Interface}
+   */
+  resume() {
+    if (!this.paused) return;
+    this.input.resume();
+    this.paused = false;
+    this.emit('resume');
+    return this;
+  }
+
+  /**
+   * Writes either `data` or a `key` sequence identified by
+   * `key` to the `output`.
+   * @param {string} d
+   * @param {{
+   *   ctrl?: boolean;
+   *   meta?: boolean;
+   *   shift?: boolean;
+   *   name?: string;
+   *   }} [key]
+   * @returns {void}
+   */
+  write(d, key) {
+    if (this.paused) this.resume();
+    if (this.terminal) {
+      this[kTtyWrite](d, key);
+    } else {
+      this[kNormalWrite](d);
+    }
+  }
+
+  [kNormalWrite](b) {
+    if (b === undefined) {
+      return;
+    }
+    let string = this[kDecoder].write(b);
+    if (
+      this[kSawReturnAt] &&
+      DateNow() - this[kSawReturnAt] <= this.crlfDelay
+    ) {
+      string = StringPrototypeReplace(string, /^\n/, '');
+      this[kSawReturnAt] = 0;
+    }
+
+    // Run test() on the new string chunk, not on the entire line buffer.
+    const newPartContainsEnding = RegExpPrototypeTest(lineEnding, string);
+
+    if (this[kLine_buffer]) {
+      string = this[kLine_buffer] + string;
+      this[kLine_buffer] = null;
+    }
+    if (newPartContainsEnding) {
+      this[kSawReturnAt] = StringPrototypeEndsWith(string, '\r') ?
+        DateNow() :
+        0;
+
+      // Got one or more newlines; process into "line" events
+      const lines = StringPrototypeSplit(string, lineEnding);
+      // Either '' or (conceivably) the unfinished portion of the next line
+      string = ArrayPrototypePop(lines);
+      this[kLine_buffer] = string;
+      for (let n = 0; n < lines.length; n++) this[kOnLine](lines[n]);
+    } else if (string) {
+      // No newlines this time, save what we have for next time
+      this[kLine_buffer] = string;
+    }
+  }
+
+  [kInsertString](c) {
+    if (this.cursor < this.line.length) {
+      const beg = StringPrototypeSlice(this.line, 0, this.cursor);
+      const end = StringPrototypeSlice(
+        this.line,
+        this.cursor,
+        this.line.length
+      );
+      this.line = beg + c + end;
+      this.cursor += c.length;
+      this[kRefreshLine]();
+    } else {
+      this.line += c;
+      this.cursor += c.length;
+
+      if (this.getCursorPos().cols === 0) {
+        this[kRefreshLine]();
+      } else {
+        this[kWriteToOutput](c);
+      }
+    }
+  }
+
+  async [kTabComplete](lastKeypressWasTab) {
+    this.pause();
+    const string = StringPrototypeSlice(this.line, 0, this.cursor);
+    let value;
+    try {
+      value = await this.completer(string);
+    } catch (err) {
+      this[kWriteToOutput](`Tab completion error: ${inspect(err)}`);
+      return;
+    } finally {
+      this.resume();
+    }
+    this[kTabCompleter](lastKeypressWasTab, value);
+  }
+
+  [kTabCompleter](lastKeypressWasTab, { 0: completions, 1: completeOn }) {
+    // Result and the text that was completed.
+
+    if (!completions || completions.length === 0) {
+      return;
+    }
+
+    // If there is a common prefix to all matches, then apply that portion.
+    const prefix = commonPrefix(
+      ArrayPrototypeFilter(completions, (e) => e !== '')
+    );
+    if (StringPrototypeStartsWith(prefix, completeOn) &&
+        prefix.length > completeOn.length) {
+      this[kInsertString](StringPrototypeSlice(prefix, completeOn.length));
+      return;
+    } else if (!StringPrototypeStartsWith(completeOn, prefix)) {
+      this.line = StringPrototypeSlice(this.line,
+                                       0,
+                                       this.cursor - completeOn.length) +
+                  prefix +
+                  StringPrototypeSlice(this.line,
+                                       this.cursor,
+                                       this.line.length);
+      this.cursor = this.cursor - completeOn.length + prefix.length;
+      this._refreshLine();
+      return;
+    }
+
+    if (!lastKeypressWasTab) {
+      return;
+    }
+
+    // Apply/show completions.
+    const completionsWidth = ArrayPrototypeMap(completions, (e) =>
+      getStringWidth(e)
+    );
+    const width = MathMaxApply(completionsWidth) + 2; // 2 space padding
+    let maxColumns = MathFloor(this.columns / width) || 1;
+    if (maxColumns === Infinity) {
+      maxColumns = 1;
+    }
+    let output = '\r\n';
+    let lineIndex = 0;
+    let whitespace = 0;
+    for (let i = 0; i < completions.length; i++) {
+      const completion = completions[i];
+      if (completion === '' || lineIndex === maxColumns) {
+        output += '\r\n';
+        lineIndex = 0;
+        whitespace = 0;
+      } else {
+        output += StringPrototypeRepeat(' ', whitespace);
+      }
+      if (completion !== '') {
+        output += completion;
+        whitespace = width - completionsWidth[i];
+        lineIndex++;
+      } else {
+        output += '\r\n';
+      }
+    }
+    if (lineIndex !== 0) {
+      output += '\r\n\r\n';
+    }
+    this[kWriteToOutput](output);
+    this[kRefreshLine]();
+  }
+
+  [kWordLeft]() {
+    if (this.cursor > 0) {
+      // Reverse the string and match a word near beginning
+      // to avoid quadratic time complexity
+      const leading = StringPrototypeSlice(this.line, 0, this.cursor);
+      const reversed = ArrayPrototypeJoin(
+        ArrayPrototypeReverse(ArrayFrom(leading)),
+        ''
+      );
+      const match = StringPrototypeMatch(reversed, /^\s*(?:[^\w\s]+|\w+)?/);
+      this[kMoveCursor](-match[0].length);
+    }
+  }
+
+  [kWordRight]() {
+    if (this.cursor < this.line.length) {
+      const trailing = StringPrototypeSlice(this.line, this.cursor);
+      const match = StringPrototypeMatch(trailing, /^(?:\s+|[^\w\s]+|\w+)\s*/);
+      this[kMoveCursor](match[0].length);
+    }
+  }
+
+  [kDeleteLeft]() {
+    if (this.cursor > 0 && this.line.length > 0) {
+      // The number of UTF-16 units comprising the character to the left
+      const charSize = charLengthLeft(this.line, this.cursor);
+      this.line =
+        StringPrototypeSlice(this.line, 0, this.cursor - charSize) +
+        StringPrototypeSlice(this.line, this.cursor, this.line.length);
+
+      this.cursor -= charSize;
+      this[kRefreshLine]();
+    }
+  }
+
+  [kDeleteRight]() {
+    if (this.cursor < this.line.length) {
+      // The number of UTF-16 units comprising the character to the left
+      const charSize = charLengthAt(this.line, this.cursor);
+      this.line =
+        StringPrototypeSlice(this.line, 0, this.cursor) +
+        StringPrototypeSlice(
+          this.line,
+          this.cursor + charSize,
+          this.line.length
+        );
+      this[kRefreshLine]();
+    }
+  }
+
+  [kDeleteWordLeft]() {
+    if (this.cursor > 0) {
+      // Reverse the string and match a word near beginning
+      // to avoid quadratic time complexity
+      let leading = StringPrototypeSlice(this.line, 0, this.cursor);
+      const reversed = ArrayPrototypeJoin(
+        ArrayPrototypeReverse(ArrayFrom(leading)),
+        ''
+      );
+      const match = StringPrototypeMatch(reversed, /^\s*(?:[^\w\s]+|\w+)?/);
+      leading = StringPrototypeSlice(
+        leading,
+        0,
+        leading.length - match[0].length
+      );
+      this.line =
+        leading +
+        StringPrototypeSlice(this.line, this.cursor, this.line.length);
+      this.cursor = leading.length;
+      this[kRefreshLine]();
+    }
+  }
+
+  [kDeleteWordRight]() {
+    if (this.cursor < this.line.length) {
+      const trailing = StringPrototypeSlice(this.line, this.cursor);
+      const match = StringPrototypeMatch(trailing, /^(?:\s+|\W+|\w+)\s*/);
+      this.line =
+        StringPrototypeSlice(this.line, 0, this.cursor) +
+        StringPrototypeSlice(trailing, match[0].length);
+      this[kRefreshLine]();
+    }
+  }
+
+  [kDeleteLineLeft]() {
+    this.line = StringPrototypeSlice(this.line, this.cursor);
+    this.cursor = 0;
+    this[kRefreshLine]();
+  }
+
+  [kDeleteLineRight]() {
+    this.line = StringPrototypeSlice(this.line, 0, this.cursor);
+    this[kRefreshLine]();
+  }
+
+  clearLine() {
+    this[kMoveCursor](+Infinity);
+    this[kWriteToOutput]('\r\n');
+    this.line = '';
+    this.cursor = 0;
+    this.prevRows = 0;
+  }
+
+  [kLine]() {
+    const line = this[kAddHistory]();
+    this.clearLine();
+    this[kOnLine](line);
+  }
+
+  // TODO(BridgeAR): Add underscores to the search part and a red background in
+  // case no match is found. This should only be the visual part and not the
+  // actual line content!
+  // TODO(BridgeAR): In case the substring based search is active and the end is
+  // reached, show a comment how to search the history as before. E.g., using
+  // <ctrl> + N. Only show this after two/three UPs or DOWNs, not on the first
+  // one.
+  [kHistoryNext]() {
+    if (this.historyIndex >= 0) {
+      const search = this[kSubstringSearch] || '';
+      let index = this.historyIndex - 1;
+      while (
+        index >= 0 &&
+        (!StringPrototypeStartsWith(this.history[index], search) ||
+          this.line === this.history[index])
+      ) {
+        index--;
+      }
+      if (index === -1) {
+        this.line = search;
+      } else {
+        this.line = this.history[index];
+      }
+      this.historyIndex = index;
+      this.cursor = this.line.length; // Set cursor to end of line.
+      this[kRefreshLine]();
+    }
+  }
+
+  [kHistoryPrev]() {
+    if (this.historyIndex < this.history.length && this.history.length) {
+      const search = this[kSubstringSearch] || '';
+      let index = this.historyIndex + 1;
+      while (
+        index < this.history.length &&
+        (!StringPrototypeStartsWith(this.history[index], search) ||
+          this.line === this.history[index])
+      ) {
+        index++;
+      }
+      if (index === this.history.length) {
+        this.line = search;
+      } else {
+        this.line = this.history[index];
+      }
+      this.historyIndex = index;
+      this.cursor = this.line.length; // Set cursor to end of line.
+      this[kRefreshLine]();
+    }
+  }
+
+  // Returns the last character's display position of the given string
+  [kGetDisplayPos](str) {
+    let offset = 0;
+    const col = this.columns;
+    let rows = 0;
+    str = stripVTControlCharacters(str);
+    for (const char of new SafeStringIterator(str)) {
+      if (char === '\n') {
+        // Rows must be incremented by 1 even if offset = 0 or col = +Infinity.
+        rows += MathCeil(offset / col) || 1;
+        offset = 0;
+        continue;
+      }
+      // Tabs must be aligned by an offset of the tab size.
+      if (char === '\t') {
+        offset += this.tabSize - (offset % this.tabSize);
+        continue;
+      }
+      const width = getStringWidth(char, false /* stripVTControlCharacters */);
+      if (width === 0 || width === 1) {
+        offset += width;
+      } else {
+        // width === 2
+        if ((offset + 1) % col === 0) {
+          offset++;
+        }
+        offset += 2;
+      }
+    }
+    const cols = offset % col;
+    rows += (offset - cols) / col;
+    return { cols, rows };
+  }
+
+  /**
+   * Returns the real position of the cursor in relation
+   * to the input prompt + string.
+   * @returns {{
+   *   rows: number;
+   *   cols: number;
+   *   }}
+   */
+  getCursorPos() {
+    const strBeforeCursor =
+      this[kPrompt] + StringPrototypeSlice(this.line, 0, this.cursor);
+    return this[kGetDisplayPos](strBeforeCursor);
+  }
+
+  // This function moves cursor dx places to the right
+  // (-dx for left) and refreshes the line if it is needed.
+  [kMoveCursor](dx) {
+    if (dx === 0) {
+      return;
+    }
+    const oldPos = this.getCursorPos();
+    this.cursor += dx;
+
+    // Bounds check
+    if (this.cursor < 0) {
+      this.cursor = 0;
+    } else if (this.cursor > this.line.length) {
+      this.cursor = this.line.length;
+    }
+
+    const newPos = this.getCursorPos();
+
+    // Check if cursor stayed on the line.
+    if (oldPos.rows === newPos.rows) {
+      const diffWidth = newPos.cols - oldPos.cols;
+      moveCursor(this.output, diffWidth, 0);
+    } else {
+      this[kRefreshLine]();
+    }
+  }
+
+  // Handle a write from the tty
+  [kTtyWrite](s, key) {
+    const previousKey = this[kPreviousKey];
+    key = key || {};
+    this[kPreviousKey] = key;
+
+    // Activate or deactivate substring search.
+    if (
+      (key.name === 'up' || key.name === 'down') &&
+      !key.ctrl &&
+      !key.meta &&
+      !key.shift
+    ) {
+      if (this[kSubstringSearch] === null) {
+        this[kSubstringSearch] = StringPrototypeSlice(
+          this.line,
+          0,
+          this.cursor
+        );
+      }
+    } else if (this[kSubstringSearch] !== null) {
+      this[kSubstringSearch] = null;
+      // Reset the index in case there's no match.
+      if (this.history.length === this.historyIndex) {
+        this.historyIndex = -1;
+      }
+    }
+
+    // Ignore escape key, fixes
+    // https://github.com/nodejs/node-v0.x-archive/issues/2876.
+    if (key.name === 'escape') return;
+
+    if (key.ctrl && key.shift) {
+      /* Control and shift pressed */
+      switch (key.name) {
+        // TODO(BridgeAR): The transmitted escape sequence is `\b` and that is
+        // identical to <ctrl>-h. It should have a unique escape sequence.
+        case 'backspace':
+          this[kDeleteLineLeft]();
+          break;
+
+        case 'delete':
+          this[kDeleteLineRight]();
+          break;
+      }
+    } else if (key.ctrl) {
+      /* Control key pressed */
+
+      switch (key.name) {
+        case 'c':
+          if (this.listenerCount('SIGINT') > 0) {
+            this.emit('SIGINT');
+          } else {
+            // This readline instance is finished
+            this.close();
+          }
+          break;
+
+        case 'h': // delete left
+          this[kDeleteLeft]();
+          break;
+
+        case 'd': // delete right or EOF
+          if (this.cursor === 0 && this.line.length === 0) {
+            // This readline instance is finished
+            this.close();
+          } else if (this.cursor < this.line.length) {
+            this[kDeleteRight]();
+          }
+          break;
+
+        case 'u': // Delete from current to start of line
+          this[kDeleteLineLeft]();
+          break;
+
+        case 'k': // Delete from current to end of line
+          this[kDeleteLineRight]();
+          break;
+
+        case 'a': // Go to the start of the line
+          this[kMoveCursor](-Infinity);
+          break;
+
+        case 'e': // Go to the end of the line
+          this[kMoveCursor](+Infinity);
+          break;
+
+        case 'b': // back one character
+          this[kMoveCursor](-charLengthLeft(this.line, this.cursor));
+          break;
+
+        case 'f': // Forward one character
+          this[kMoveCursor](+charLengthAt(this.line, this.cursor));
+          break;
+
+        case 'l': // Clear the whole screen
+          cursorTo(this.output, 0, 0);
+          clearScreenDown(this.output);
+          this[kRefreshLine]();
+          break;
+
+        case 'n': // next history item
+          this[kHistoryNext]();
+          break;
+
+        case 'p': // Previous history item
+          this[kHistoryPrev]();
+          break;
+
+        case 'z':
+          if (process.platform === 'win32') break;
+          if (this.listenerCount('SIGTSTP') > 0) {
+            this.emit('SIGTSTP');
+          } else {
+            process.once('SIGCONT', () => {
+              // Don't raise events if stream has already been abandoned.
+              if (!this.paused) {
+                // Stream must be paused and resumed after SIGCONT to catch
+                // SIGINT, SIGTSTP, and EOF.
+                this.pause();
+                this.emit('SIGCONT');
+              }
+              // Explicitly re-enable "raw mode" and move the cursor to
+              // the correct position.
+              // See https://github.com/joyent/node/issues/3295.
+              this[kSetRawMode](true);
+              this[kRefreshLine]();
+            });
+            this[kSetRawMode](false);
+            process.kill(process.pid, 'SIGTSTP');
+          }
+          break;
+
+        case 'w': // Delete backwards to a word boundary
+        // TODO(BridgeAR): The transmitted escape sequence is `\b` and that is
+        // identical to <ctrl>-h. It should have a unique escape sequence.
+        // Falls through
+        case 'backspace':
+          this[kDeleteWordLeft]();
+          break;
+
+        case 'delete': // Delete forward to a word boundary
+          this[kDeleteWordRight]();
+          break;
+
+        case 'left':
+          this[kWordLeft]();
+          break;
+
+        case 'right':
+          this[kWordRight]();
+          break;
+      }
+    } else if (key.meta) {
+      /* Meta key pressed */
+
+      switch (key.name) {
+        case 'b': // backward word
+          this[kWordLeft]();
+          break;
+
+        case 'f': // forward word
+          this[kWordRight]();
+          break;
+
+        case 'd': // delete forward word
+        case 'delete':
+          this[kDeleteWordRight]();
+          break;
+
+        case 'backspace': // Delete backwards to a word boundary
+          this[kDeleteWordLeft]();
+          break;
+      }
+    } else {
+      /* No modifier keys used */
+
+      // \r bookkeeping is only relevant if a \n comes right after.
+      if (this[kSawReturnAt] && key.name !== 'enter') this[kSawReturnAt] = 0;
+
+      switch (key.name) {
+        case 'return': // Carriage return, i.e. \r
+          this[kSawReturnAt] = DateNow();
+          this[kLine]();
+          break;
+
+        case 'enter':
+          // When key interval > crlfDelay
+          if (
+            this[kSawReturnAt] === 0 ||
+            DateNow() - this[kSawReturnAt] > this.crlfDelay
+          ) {
+            this[kLine]();
+          }
+          this[kSawReturnAt] = 0;
+          break;
+
+        case 'backspace':
+          this[kDeleteLeft]();
+          break;
+
+        case 'delete':
+          this[kDeleteRight]();
+          break;
+
+        case 'left':
+          // Obtain the code point to the left
+          this[kMoveCursor](-charLengthLeft(this.line, this.cursor));
+          break;
+
+        case 'right':
+          this[kMoveCursor](+charLengthAt(this.line, this.cursor));
+          break;
+
+        case 'home':
+          this[kMoveCursor](-Infinity);
+          break;
+
+        case 'end':
+          this[kMoveCursor](+Infinity);
+          break;
+
+        case 'up':
+          this[kHistoryPrev]();
+          break;
+
+        case 'down':
+          this[kHistoryNext]();
+          break;
+
+        case 'tab':
+          // If tab completion enabled, do that...
+          if (
+            typeof this.completer === 'function' &&
+            this.isCompletionEnabled
+          ) {
+            const lastKeypressWasTab =
+              previousKey && previousKey.name === 'tab';
+            this[kTabComplete](lastKeypressWasTab);
+            break;
+          }
+        // falls through
+        default:
+          if (typeof s === 'string' && s) {
+            const lines = StringPrototypeSplit(s, /\r\n|\n|\r/);
+            for (let i = 0, len = lines.length; i < len; i++) {
+              if (i > 0) {
+                this[kLine]();
+              }
+              this[kInsertString](lines[i]);
+            }
+          }
+      }
+    }
+  }
+
+  /**
+   * Creates an `AsyncIterator` object that iterates through
+   * each line in the input stream as a string.
+   * @typedef {{
+   *   [Symbol.asyncIterator]: () => InterfaceAsyncIterator,
+   *   next: () => Promise<string>
+   * }} InterfaceAsyncIterator
+   * @returns {InterfaceAsyncIterator}
+   */
+  [SymbolAsyncIterator]() {
+    if (this[kLineObjectStream] === undefined) {
+      if (Readable === undefined) {
+        Readable = require('stream').Readable;
+      }
+      const readable = new Readable({
+        objectMode: true,
+        read: () => {
+          this.resume();
+        },
+        destroy: (err, cb) => {
+          this.off('line', lineListener);
+          this.off('close', closeListener);
+          this.close();
+          cb(err);
+        },
+      });
+      const lineListener = (input) => {
+        if (!readable.push(input)) {
+          // TODO(rexagod): drain to resume flow
+          this.pause();
+        }
+      };
+      const closeListener = () => {
+        readable.push(null);
+      };
+      const errorListener = (err) => {
+        readable.destroy(err);
+      };
+      this.on('error', errorListener);
+      this.on('line', lineListener);
+      this.on('close', closeListener);
+      this[kLineObjectStream] = readable;
+    }
+
+    return this[kLineObjectStream][SymbolAsyncIterator]();
+  }
+}
+
+module.exports = {
+  Interface,
+  InterfaceConstructor,
+  kAddHistory,
+  kDecoder,
+  kDeleteLeft,
+  kDeleteLineLeft,
+  kDeleteLineRight,
+  kDeleteRight,
+  kDeleteWordLeft,
+  kDeleteWordRight,
+  kGetDisplayPos,
+  kHistoryNext,
+  kHistoryPrev,
+  kInsertString,
+  kLine,
+  kLine_buffer,
+  kMoveCursor,
+  kNormalWrite,
+  kOldPrompt,
+  kOnLine,
+  kPreviousKey,
+  kPrompt,
+  kQuestionCallback,
+  kQuestionCancel,
+  kRefreshLine,
+  kSawKeyPress,
+  kSawReturnAt,
+  kSetRawMode,
+  kTabComplete,
+  kTabCompleter,
+  kTtyWrite,
+  kWordLeft,
+  kWordRight,
+  kWriteToOutput,
+};