repl.js

// Copyright Joyent, Inc. and other Node contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to permit
// persons to whom the Software is furnished to do so, subject to the
// following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
// USE OR OTHER DEALINGS IN THE SOFTWARE.

/* A REPL library that you can include in your own code to get a runtime
 * interface to your program.
 *
 *   const repl = require("repl");
 *   // start repl on stdin
 *   repl.start("prompt> ");
 *
 *   // listen for unix socket connections and start repl on them
 *   net.createServer(function(socket) {
 *     repl.start("node via Unix socket> ", socket);
 *   }).listen("/tmp/node-repl-sock");
 *
 *   // listen for TCP socket connections and start repl on them
 *   net.createServer(function(socket) {
 *     repl.start("node via TCP socket> ", socket);
 *   }).listen(5001);
 *
 *   // expose foo to repl context
 *   repl.start("node > ").context.foo = "stdin is fun";
 */

'use strict';

const {
  ArrayPrototypeAt,
  ArrayPrototypeFilter,
  ArrayPrototypeFindLastIndex,
  ArrayPrototypeForEach,
  ArrayPrototypeIncludes,
  ArrayPrototypeJoin,
  ArrayPrototypeMap,
  ArrayPrototypePop,
  ArrayPrototypePush,
  ArrayPrototypePushApply,
  ArrayPrototypeReverse,
  ArrayPrototypeShift,
  ArrayPrototypeSlice,
  ArrayPrototypeSome,
  ArrayPrototypeSort,
  ArrayPrototypeUnshift,
  Boolean,
  Error: MainContextError,
  FunctionPrototypeBind,
  JSONStringify,
  MathMaxApply,
  NumberIsNaN,
  NumberParseFloat,
  ObjectAssign,
  ObjectDefineProperty,
  ObjectGetOwnPropertyDescriptor,
  ObjectGetOwnPropertyNames,
  ObjectGetPrototypeOf,
  ObjectKeys,
  ObjectSetPrototypeOf,
  Promise,
  ReflectApply,
  RegExp,
  RegExpPrototypeExec,
  SafePromiseRace,
  SafeSet,
  SafeWeakSet,
  StringPrototypeCharAt,
  StringPrototypeCodePointAt,
  StringPrototypeEndsWith,
  StringPrototypeIncludes,
  StringPrototypeRepeat,
  StringPrototypeSlice,
  StringPrototypeSplit,
  StringPrototypeStartsWith,
  StringPrototypeToLocaleLowerCase,
  StringPrototypeTrim,
  StringPrototypeTrimStart,
  Symbol,
  SyntaxError,
  SyntaxErrorPrototype,
  globalThis,
} = primordials;

const { BuiltinModule } = require('internal/bootstrap/realm');
const {
  makeRequireFunction,
  addBuiltinLibsToObject,
} = require('internal/modules/helpers');
const {
  isIdentifierStart,
  isIdentifierChar,
  parse: acornParse,
} = require('internal/deps/acorn/acorn/dist/acorn');
const acornWalk = require('internal/deps/acorn/acorn-walk/dist/walk');
const {
  decorateErrorStack,
  isError,
  deprecate,
  deprecateInstantiation,
  SideEffectFreeRegExpPrototypeSymbolReplace,
  SideEffectFreeRegExpPrototypeSymbolSplit,
} = require('internal/util');
const { inspect } = require('internal/util/inspect');
const vm = require('vm');

const { runInThisContext, runInContext } = vm.Script.prototype;

const path = require('path');
const fs = require('fs');
const { Interface } = require('readline');
const {
  commonPrefix,
} = require('internal/readline/utils');
const { Console } = require('console');
const { shouldColorize } = require('internal/util/colors');
const CJSModule = require('internal/modules/cjs/loader').Module;
let _builtinLibs = ArrayPrototypeFilter(
  CJSModule.builtinModules,
  (e) => e[0] !== '_' && !StringPrototypeStartsWith(e, 'node:'),
);
const nodeSchemeBuiltinLibs = ArrayPrototypeMap(
  _builtinLibs, (lib) => `node:${lib}`);
ArrayPrototypeForEach(
  BuiltinModule.getSchemeOnlyModuleNames(),
  (lib) => ArrayPrototypePush(nodeSchemeBuiltinLibs, `node:${lib}`),
);
const domain = require('domain');
let debug = require('internal/util/debuglog').debuglog('repl', (fn) => {
  debug = fn;
});
const {
  ErrorPrepareStackTrace,
  codes: {
    ERR_CANNOT_WATCH_SIGINT,
    ERR_INVALID_REPL_EVAL_CONFIG,
    ERR_INVALID_REPL_INPUT,
    ERR_MISSING_ARGS,
    ERR_SCRIPT_EXECUTION_INTERRUPTED,
  },
  isErrorStackTraceLimitWritable,
  overrideStackTrace,
} = require('internal/errors');
const { sendInspectorCommand } = require('internal/util/inspector');
const { getOptionValue } = require('internal/options');
const {
  validateFunction,
  validateObject,
} = require('internal/validators');
const experimentalREPLAwait = getOptionValue(
  '--experimental-repl-await',
);
const pendingDeprecation = getOptionValue('--pending-deprecation');
const {
  REPL_MODE_SLOPPY,
  REPL_MODE_STRICT,
  isRecoverableError,
  kStandaloneREPL,
  setupPreview,
  setupReverseSearch,
  isObjectLiteral,
} = require('internal/repl/utils');
const {
  constants: {
    ALL_PROPERTIES,
    SKIP_SYMBOLS,
  },
  getOwnNonIndexProperties,
} = internalBinding('util');
const {
  startSigintWatchdog,
  stopSigintWatchdog,
} = internalBinding('contextify');

const history = require('internal/repl/history');
const {
  extensionFormatMap,
} = require('internal/modules/esm/formats');
const {
  makeContextifyScript,
} = require('internal/vm');
const {
  kMultilinePrompt,
  kLastCommandErrored,
  kNormalizeHistoryLineEndings,
} = require('internal/readline/interface');
let nextREPLResourceNumber = 1;
// This prevents v8 code cache from getting confused and using a different
// cache from a resource of the same name
function getREPLResourceName() {
  return `REPL${nextREPLResourceNumber++}`;
}

// Lazy-loaded.
let processTopLevelAwait;

const globalBuiltins =
  new SafeSet(vm.runInNewContext('Object.getOwnPropertyNames(globalThis)'));

const parentModule = module;
const domainSet = new SafeWeakSet();

const kBufferedCommandSymbol = Symbol('bufferedCommand');
const kContextId = Symbol('contextId');
const kLoadingSymbol = Symbol('loading');

let addedNewListener = false;

try {
  // Hack for require.resolve("./relative") to work properly.
  module.filename = path.resolve('repl');
} catch {
  // path.resolve('repl') fails when the current working directory has been
  // deleted.  Fall back to the directory name of the (absolute) executable
  // path.  It's not really correct but what are the alternatives?
  const dirname = path.dirname(process.execPath);
  module.filename = path.resolve(dirname, 'repl');
}

// Hack for repl require to work properly with node_modules folders
module.paths = CJSModule._nodeModulePaths(module.filename);

// This is the default "writer" value, if none is passed in the REPL options,
// and it can be overridden by custom print functions, such as `probe` or
// `eyes.js`.
const writer = (obj) => inspect(obj, writer.options);
writer.options = { ...inspect.defaultOptions, showProxy: true };

// Converts static import statement to dynamic import statement
const toDynamicImport = (codeLine) => {
  let dynamicImportStatement = '';
  const ast = acornParse(codeLine, { __proto__: null, sourceType: 'module', ecmaVersion: 'latest' });
  acornWalk.ancestor(ast, {
    ImportDeclaration(node) {
      const awaitDynamicImport = `await import(${JSONStringify(node.source.value)});`;
      if (node.specifiers.length === 0) {
        dynamicImportStatement += awaitDynamicImport;
      } else if (node.specifiers.length === 1 && node.specifiers[0].type === 'ImportNamespaceSpecifier') {
        dynamicImportStatement += `const ${node.specifiers[0].local.name} = ${awaitDynamicImport}`;
      } else {
        const importNames = ArrayPrototypeJoin(ArrayPrototypeMap(node.specifiers, ({ local, imported }) =>
          (local.name === imported?.name ? local.name : `${imported?.name ?? 'default'}: ${local.name}`),
        ), ', ');
        dynamicImportStatement += `const { ${importNames} } = ${awaitDynamicImport}`;
      }
    },
  });
  return dynamicImportStatement;
};

function REPLServer(prompt,
                    stream,
                    eval_,
                    useGlobal,
                    ignoreUndefined,
                    replMode) {
  if (!(this instanceof REPLServer)) {
    return deprecateInstantiation(REPLServer, 'DEP0185', prompt, stream, eval_, useGlobal, ignoreUndefined, replMode);
  }

  let options;
  if (prompt !== null && typeof prompt === 'object') {
    // An options object was given.
    options = { ...prompt };
    stream = options.stream || options.socket;
    eval_ = options.eval;
    useGlobal = options.useGlobal;
    ignoreUndefined = options.ignoreUndefined;
    prompt = options.prompt;
    replMode = options.replMode;
  } else {
    options = {};
  }

  if (!options.input && !options.output) {
    // Legacy API, passing a 'stream'/'socket' option.
    // Use stdin and stdout as the default streams if none were given.
    stream ||= process;

    // We're given a duplex readable/writable Stream, like a `net.Socket`
    // or a custom object with 2 streams, or the `process` object.
    options.input = stream.stdin || stream;
    options.output = stream.stdout || stream;
  }

  if (options.terminal === undefined) {
    options.terminal = options.output.isTTY;
  }
  options.terminal = !!options.terminal;

  if (options.terminal && options.useColors === undefined) {
    // If possible, check if stdout supports colors or not.
    options.useColors = shouldColorize(options.output);
  }

  // TODO(devsnek): Add a test case for custom eval functions.
  const preview = options.terminal &&
    (options.preview !== undefined ? !!options.preview : !eval_);

  ObjectDefineProperty(this, 'inputStream', {
    __proto__: null,
    get: pendingDeprecation ?
      deprecate(() => this.input,
                'repl.inputStream and repl.outputStream are deprecated. ' +
                  'Use repl.input and repl.output instead',
                'DEP0141') :
      () => this.input,
    set: pendingDeprecation ?
      deprecate((val) => this.input = val,
                'repl.inputStream and repl.outputStream are deprecated. ' +
                  'Use repl.input and repl.output instead',
                'DEP0141') :
      (val) => this.input = val,
    enumerable: false,
    configurable: true,
  });
  ObjectDefineProperty(this, 'outputStream', {
    __proto__: null,
    get: pendingDeprecation ?
      deprecate(() => this.output,
                'repl.inputStream and repl.outputStream are deprecated. ' +
                  'Use repl.input and repl.output instead',
                'DEP0141') :
      () => this.output,
    set: pendingDeprecation ?
      deprecate((val) => this.output = val,
                'repl.inputStream and repl.outputStream are deprecated. ' +
                  'Use repl.input and repl.output instead',
                'DEP0141') :
      (val) => this.output = val,
    enumerable: false,
    configurable: true,
  });

  this.allowBlockingCompletions = !!options.allowBlockingCompletions;
  this.useColors = !!options.useColors;
  this._domain = options.domain || domain.create();
  this.useGlobal = !!useGlobal;
  this.ignoreUndefined = !!ignoreUndefined;
  this.replMode = replMode || module.exports.REPL_MODE_SLOPPY;
  this.underscoreAssigned = false;
  this.last = undefined;
  this.underscoreErrAssigned = false;
  this.lastError = undefined;
  this.breakEvalOnSigint = !!options.breakEvalOnSigint;
  this.editorMode = false;
  // Context id for use with the inspector protocol.
  this[kContextId] = undefined;

  if (this.breakEvalOnSigint && eval_) {
    // Allowing this would not reflect user expectations.
    // breakEvalOnSigint affects only the behavior of the default eval().
    throw new ERR_INVALID_REPL_EVAL_CONFIG();
  }

  if (options[kStandaloneREPL]) {
    // It is possible to introspect the running REPL accessing this variable
    // from inside the REPL. This is useful for anyone working on the REPL.
    module.exports.repl = this;
  } else if (!addedNewListener) {
    // Add this listener only once and use a WeakSet that contains the REPLs
    // domains. Otherwise we'd have to add a single listener to each REPL
    // instance and that could trigger the `MaxListenersExceededWarning`.
    process.prependListener('newListener', (event, listener) => {
      if (event === 'uncaughtException' &&
          process.domain &&
          listener.name !== 'domainUncaughtExceptionClear' &&
          domainSet.has(process.domain)) {
        // Throw an error so that the event will not be added and the current
        // domain takes over. That way the user is notified about the error
        // and the current code evaluation is stopped, just as any other code
        // that contains an error.
        throw new ERR_INVALID_REPL_INPUT(
          'Listeners for `uncaughtException` cannot be used in the REPL');
      }
    });
    addedNewListener = true;
  }

  domainSet.add(this._domain);

  const savedRegExMatches = ['', '', '', '', '', '', '', '', '', ''];
  const sep = '\u0000\u0000\u0000';
  const regExMatcher = new RegExp(`^${sep}(.*)${sep}(.*)${sep}(.*)${sep}(.*)` +
                                  `${sep}(.*)${sep}(.*)${sep}(.*)${sep}(.*)` +
                                  `${sep}(.*)$`);

  eval_ ||= defaultEval;

  const self = this;

  // Pause taking in new input, and store the keys in a buffer.
  const pausedBuffer = [];
  let paused = false;
  function pause() {
    paused = true;
  }

  function unpause() {
    if (!paused) return;
    paused = false;
    let entry;
    const tmpCompletionEnabled = self.isCompletionEnabled;
    while ((entry = ArrayPrototypeShift(pausedBuffer)) !== undefined) {
      const { 0: type, 1: payload, 2: isCompletionEnabled } = entry;
      switch (type) {
        case 'key': {
          const { 0: d, 1: key } = payload;
          self.isCompletionEnabled = isCompletionEnabled;
          self._ttyWrite(d, key);
          break;
        }
        case 'close':
          self.emit('exit');
          break;
      }
      if (paused) {
        break;
      }
    }
    self.isCompletionEnabled = tmpCompletionEnabled;
  }

  function defaultEval(code, context, file, cb) {
    let result, script, wrappedErr;
    let err = null;
    let wrappedCmd = false;
    let awaitPromise = false;
    const input = code;

    if (isObjectLiteral(code)) {
      // Add parentheses to make sure `code` is parsed as an expression
      code = `(${StringPrototypeTrim(code)})\n`;
      wrappedCmd = true;
    }

    const hostDefinedOptionId = Symbol(`eval:${file}`);
    let parentURL;
    try {
      const { pathToFileURL } = require('internal/url');
      // Adding `/repl` prevents dynamic imports from loading relative
      // to the parent of `process.cwd()`.
      parentURL = pathToFileURL(path.join(process.cwd(), 'repl')).href;
    } catch {
      // Continue regardless of error.
    }
    async function importModuleDynamically(specifier, _, importAttributes, phase) {
      const cascadedLoader = require('internal/modules/esm/loader').getOrInitializeCascadedLoader();
      return cascadedLoader.import(specifier, parentURL, importAttributes,
                                   phase === 'evaluation' ? cascadedLoader.kEvaluationPhase :
                                     cascadedLoader.kSourcePhase);
    }
    // `experimentalREPLAwait` is set to true by default.
    // Shall be false in case `--no-experimental-repl-await` flag is used.
    if (experimentalREPLAwait && StringPrototypeIncludes(code, 'await')) {
      if (processTopLevelAwait === undefined) {
        ({ processTopLevelAwait } = require('internal/repl/await'));
      }

      try {
        const potentialWrappedCode = processTopLevelAwait(code);
        if (potentialWrappedCode !== null) {
          code = potentialWrappedCode;
          wrappedCmd = true;
          awaitPromise = true;
        }
      } catch (e) {
        let recoverableError = false;
        if (e.name === 'SyntaxError') {
          // Remove all "await"s and attempt running the script
          // in order to detect if error is truly non recoverable
          const fallbackCode = SideEffectFreeRegExpPrototypeSymbolReplace(/\bawait\b/g, code, '');
          try {
            makeContextifyScript(
              fallbackCode,            // code
              file,                    // filename,
              0,                       // lineOffset
              0,                       // columnOffset,
              undefined,               // cachedData
              false,                   // produceCachedData
              undefined,               // parsingContext
              hostDefinedOptionId,     // hostDefinedOptionId
              importModuleDynamically, // importModuleDynamically
            );
          } catch (fallbackError) {
            if (isRecoverableError(fallbackError, fallbackCode)) {
              recoverableError = true;
              err = new Recoverable(e);
            }
          }
        }
        if (!recoverableError) {
          decorateErrorStack(e);
          err = e;
        }
      }
    }

    // First, create the Script object to check the syntax
    if (code === '\n')
      return cb(null);

    if (err === null) {
      while (true) {
        try {
          if (self.replMode === module.exports.REPL_MODE_STRICT &&
              RegExpPrototypeExec(/^\s*$/, code) === null) {
            // "void 0" keeps the repl from returning "use strict" as the result
            // value for statements and declarations that don't return a value.
            code = `'use strict'; void 0;\n${code}`;
          }
          script = makeContextifyScript(
            code,                    // code
            file,                    // filename,
            0,                       // lineOffset
            0,                       // columnOffset,
            undefined,               // cachedData
            false,                   // produceCachedData
            undefined,               // parsingContext
            hostDefinedOptionId,     // hostDefinedOptionId
            importModuleDynamically, // importModuleDynamically
          );
        } catch (e) {
          debug('parse error %j', code, e);
          if (wrappedCmd) {
            // Unwrap and try again
            wrappedCmd = false;
            awaitPromise = false;
            code = input;
            wrappedErr = e;
            continue;
          }
          // Preserve original error for wrapped command
          const error = wrappedErr || e;
          if (isRecoverableError(error, code))
            err = new Recoverable(error);
          else
            err = error;
        }
        break;
      }
    }

    // This will set the values from `savedRegExMatches` to corresponding
    // predefined RegExp properties `RegExp.$1`, `RegExp.$2` ... `RegExp.$9`
    RegExpPrototypeExec(regExMatcher,
                        ArrayPrototypeJoin(savedRegExMatches, sep));

    let finished = false;
    function finishExecution(err, result) {
      if (finished) return;
      finished = true;

      // After executing the current expression, store the values of RegExp
      // predefined properties back in `savedRegExMatches`
      for (let idx = 1; idx < savedRegExMatches.length; idx += 1) {
        savedRegExMatches[idx] = RegExp[`$${idx}`];
      }

      cb(err, result);
    }

    if (!err) {
      // Unset raw mode during evaluation so that Ctrl+C raises a signal.
      let previouslyInRawMode;
      if (self.breakEvalOnSigint) {
        // Start the SIGINT watchdog before entering raw mode so that a very
        // quick Ctrl+C doesn't lead to aborting the process completely.
        if (!startSigintWatchdog())
          throw new ERR_CANNOT_WATCH_SIGINT();
        previouslyInRawMode = self._setRawMode(false);
      }

      try {
        try {
          const scriptOptions = {
            displayErrors: false,
            breakOnSigint: self.breakEvalOnSigint,
          };

          if (self.useGlobal) {
            result = ReflectApply(runInThisContext, script, [scriptOptions]);
          } else {
            result = ReflectApply(runInContext, script, [context, scriptOptions]);
          }
        } finally {
          if (self.breakEvalOnSigint) {
            // Reset terminal mode to its previous value.
            self._setRawMode(previouslyInRawMode);

            // Returns true if there were pending SIGINTs *after* the script
            // has terminated without being interrupted itself.
            if (stopSigintWatchdog()) {
              self.emit('SIGINT');
            }
          }
        }
      } catch (e) {
        err = e;

        if (process.domain) {
          debug('not recoverable, send to domain');
          process.domain.emit('error', err);
          process.domain.exit();
          return;
        }
      }

      if (awaitPromise && !err) {
        let sigintListener;
        pause();
        let promise = result;
        if (self.breakEvalOnSigint) {
          const interrupt = new Promise((resolve, reject) => {
            sigintListener = () => {
              const tmp = MainContextError.stackTraceLimit;
              if (isErrorStackTraceLimitWritable()) MainContextError.stackTraceLimit = 0;
              const err = new ERR_SCRIPT_EXECUTION_INTERRUPTED();
              if (isErrorStackTraceLimitWritable()) MainContextError.stackTraceLimit = tmp;
              reject(err);
            };
            prioritizedSigintQueue.add(sigintListener);
          });
          promise = SafePromiseRace([promise, interrupt]);
        }

        (async () => {
          try {
            const result = (await promise)?.value;
            finishExecution(null, result);
          } catch (err) {
            if (err && process.domain) {
              debug('not recoverable, send to domain');
              process.domain.emit('error', err);
              process.domain.exit();
              return;
            }
            finishExecution(err);
          } finally {
            // Remove prioritized SIGINT listener if it was not called.
            prioritizedSigintQueue.delete(sigintListener);
            unpause();
          }
        })();
      }
    }

    if (!awaitPromise || err) {
      finishExecution(err, result);
    }
  }

  self.eval = self._domain.bind(eval_);

  self._domain.on('error', function debugDomainError(e) {
    debug('domain error');
    let errStack = '';

    if (typeof e === 'object' && e !== null) {
      overrideStackTrace.set(e, (error, stackFrames) => {
        let frames;
        if (typeof stackFrames === 'object') {
          // Search from the bottom of the call stack to
          // find the first frame with a null function name
          const idx = ArrayPrototypeFindLastIndex(
            stackFrames,
            (frame) => frame.getFunctionName() === null,
          );
          // If found, get rid of it and everything below it
          frames = ArrayPrototypeSlice(stackFrames, 0, idx);
        } else {
          frames = stackFrames;
        }
        // FIXME(devsnek): this is inconsistent with the checks
        // that the real prepareStackTrace dispatch uses in
        // lib/internal/errors.js.
        if (typeof MainContextError.prepareStackTrace === 'function') {
          return MainContextError.prepareStackTrace(error, frames);
        }
        return ErrorPrepareStackTrace(error, frames);
      });
      decorateErrorStack(e);

      if (e.domainThrown) {
        delete e.domain;
        delete e.domainThrown;
      }

      if (isError(e)) {
        if (e.stack) {
          if (e.name === 'SyntaxError') {
            // Remove stack trace.
            e.stack = SideEffectFreeRegExpPrototypeSymbolReplace(
              /^\s+at\s.*\n?/gm,
              SideEffectFreeRegExpPrototypeSymbolReplace(/^REPL\d+:\d+\r?\n/, e.stack, ''),
              '');
            const importErrorStr = 'Cannot use import statement outside a ' +
              'module';
            if (StringPrototypeIncludes(e.message, importErrorStr)) {
              e.message = 'Cannot use import statement inside the Node.js ' +
                'REPL, alternatively use dynamic import: ' + toDynamicImport(ArrayPrototypeAt(self.lines, -1));
              e.stack = SideEffectFreeRegExpPrototypeSymbolReplace(
                /SyntaxError:.*\n/,
                e.stack,
                `SyntaxError: ${e.message}\n`);
            }
          } else if (self.replMode === module.exports.REPL_MODE_STRICT) {
            e.stack = SideEffectFreeRegExpPrototypeSymbolReplace(
              /(\s+at\s+REPL\d+:)(\d+)/,
              e.stack,
              (_, pre, line) => pre + (line - 1),
            );
          }
        }
        errStack = self.writer(e);

        // Remove one line error braces to keep the old style in place.
        if (errStack[0] === '[' && errStack[errStack.length - 1] === ']') {
          errStack = StringPrototypeSlice(errStack, 1, -1);
        }
      }
    }

    if (!self.underscoreErrAssigned) {
      self.lastError = e;
    }

    if (options[kStandaloneREPL] &&
        process.listenerCount('uncaughtException') !== 0) {
      process.nextTick(() => {
        process.emit('uncaughtException', e);
        self.clearBufferedCommand();
        self.lines.level = [];
        self.displayPrompt();
      });
    } else {
      if (errStack === '') {
        errStack = self.writer(e);
      }
      const lines = SideEffectFreeRegExpPrototypeSymbolSplit(/(?<=\n)/, errStack);
      let matched = false;

      errStack = '';
      ArrayPrototypeForEach(lines, (line) => {
        if (!matched &&
            RegExpPrototypeExec(/^\[?([A-Z][a-z0-9_]*)*Error/, line) !== null) {
          errStack += writer.options.breakLength >= line.length ?
            `Uncaught ${line}` :
            `Uncaught:\n${line}`;
          matched = true;
        } else {
          errStack += line;
        }
      });
      if (!matched) {
        const ln = lines.length === 1 ? ' ' : ':\n';
        errStack = `Uncaught${ln}${errStack}`;
      }
      // Normalize line endings.
      errStack += StringPrototypeEndsWith(errStack, '\n') ? '' : '\n';
      self.output.write(errStack);
      self.clearBufferedCommand();
      self.lines.level = [];
      self.displayPrompt();
    }
  });

  self.clearBufferedCommand();

  function completer(text, cb) {
    ReflectApply(complete, self,
                 [text, self.editorMode ? self.completeOnEditorMode(cb) : cb]);
  }

  ReflectApply(Interface, this, [{
    input: options.input,
    output: options.output,
    completer: options.completer || completer,
    terminal: options.terminal,
    historySize: options.historySize,
    prompt,
  }]);

  self.resetContext();

  this.commands = { __proto__: null };
  defineDefaultCommands(this);

  // Figure out which "writer" function to use
  self.writer = options.writer || module.exports.writer;

  if (self.writer === writer) {
    // Conditionally turn on ANSI coloring.
    writer.options.colors = self.useColors;

    if (options[kStandaloneREPL]) {
      ObjectDefineProperty(inspect, 'replDefaults', {
        __proto__: null,
        get() {
          return writer.options;
        },
        set(options) {
          validateObject(options, 'options');
          return ObjectAssign(writer.options, options);
        },
        enumerable: true,
        configurable: true,
      });
    }
  }

  function _parseREPLKeyword(keyword, rest) {
    const cmd = this.commands[keyword];
    if (cmd) {
      ReflectApply(cmd.action, this, [rest]);
      return true;
    }
    return false;
  }

  self.on('close', function emitExit() {
    if (paused) {
      ArrayPrototypePush(pausedBuffer, ['close']);
      return;
    }
    self.emit('exit');
  });

  let sawSIGINT = false;
  let sawCtrlD = false;
  const prioritizedSigintQueue = new SafeSet();
  self.on('SIGINT', function onSigInt() {
    if (prioritizedSigintQueue.size > 0) {
      for (const task of prioritizedSigintQueue) {
        task();
      }
      return;
    }

    const empty = self.line.length === 0;
    self.clearLine();
    _turnOffEditorMode(self);

    const cmd = self[kBufferedCommandSymbol];
    if (!(cmd && cmd.length > 0) && empty) {
      if (sawSIGINT) {
        self.close();
        sawSIGINT = false;
        return;
      }
      self.output.write(
        '(To exit, press Ctrl+C again or Ctrl+D or type .exit)\n',
      );
      sawSIGINT = true;
    } else {
      sawSIGINT = false;
    }

    self.clearBufferedCommand();
    self.lines.level = [];
    self.displayPrompt();
  });

  self.on('line', function onLine(cmd) {
    debug('line %j', cmd);
    cmd ||= '';
    sawSIGINT = false;

    if (self.editorMode) {
      self[kBufferedCommandSymbol] += cmd + '\n';

      // code alignment
      const matches = self._sawKeyPress && !self[kLoadingSymbol] ?
        RegExpPrototypeExec(/^\s+/, cmd) : null;
      if (matches) {
        const prefix = matches[0];
        self.write(prefix);
        self.line = prefix;
        self.cursor = prefix.length;
      }
      ReflectApply(_memory, self, [cmd]);
      return;
    }

    // Check REPL keywords and empty lines against a trimmed line input.
    const trimmedCmd = StringPrototypeTrim(cmd);

    // Check to see if a REPL keyword was used. If it returns true,
    // display next prompt and return.
    if (trimmedCmd) {
      if (StringPrototypeCharAt(trimmedCmd, 0) === '.' &&
          StringPrototypeCharAt(trimmedCmd, 1) !== '.' &&
          NumberIsNaN(NumberParseFloat(trimmedCmd))) {
        const matches = RegExpPrototypeExec(/^\.([^\s]+)\s*(.*)$/, trimmedCmd);
        const keyword = matches?.[1];
        const rest = matches?.[2];
        if (ReflectApply(_parseREPLKeyword, self, [keyword, rest]) === true) {
          return;
        }
        if (!self[kBufferedCommandSymbol]) {
          self.output.write('Invalid REPL keyword\n');
          finish(null);
          return;
        }
      }
    }

    const evalCmd = self[kBufferedCommandSymbol] + cmd + '\n';

    debug('eval %j', evalCmd);
    self.eval(evalCmd, self.context, getREPLResourceName(), finish);

    function finish(e, ret) {
      debug('finish', e, ret);
      ReflectApply(_memory, self, [cmd]);

      self[kLastCommandErrored] = false;

      if (e && !self[kBufferedCommandSymbol] &&
          StringPrototypeStartsWith(StringPrototypeTrim(cmd), 'npm ') &&
          !(e instanceof Recoverable)
      ) {
        self.output.write('npm should be run outside of the ' +
                                'Node.js REPL, in your normal shell.\n' +
                                '(Press Ctrl+D to exit.)\n');
        self.displayPrompt();
        return;
      }

      // If error was SyntaxError and not JSON.parse error
      if (e) {
        if (e instanceof Recoverable && !sawCtrlD) {
          // Start buffering data like that:
          // {
          // ...  x: 1
          // ... }
          self[kBufferedCommandSymbol] += cmd + '\n';
          self.displayPrompt();
          return;
        }
      }

      // In the next two if blocks, we do not use os.EOL instead of '\n'
      // because on Windows it is '\r\n'
      if (StringPrototypeIncludes(cmd, '\n')) { // If you are editing a multiline command
        self.history[0] = self[kNormalizeHistoryLineEndings](cmd, '\n', '\r');
      } else if (self[kBufferedCommandSymbol]) { // If a new multiline command was entered
        // Remove the first N lines from the self.history array
        // where N is the number of lines in the buffered command

        const lines = StringPrototypeSplit(self[kBufferedCommandSymbol], '\n');
        self.history = ArrayPrototypeSlice(self.history, lines.length);
        lines[lines.length - 1] = cmd;
        const newHistoryLine = ArrayPrototypeJoin(ArrayPrototypeReverse(lines), '\r');
        if (self.history[0] !== newHistoryLine) {
          ArrayPrototypeUnshift(self.history, newHistoryLine);
        }
      }

      if (e) {
        self._domain.emit('error', e.err || e);
        self[kLastCommandErrored] = true;
      }

      // Clear buffer if no SyntaxErrors
      self.clearBufferedCommand();
      sawCtrlD = false;

      // If we got any output - print it (if no error)
      if (!e &&
          // When an invalid REPL command is used, error message is printed
          // immediately. We don't have to print anything else. So, only when
          // the second argument to this function is there, print it.
          arguments.length === 2 &&
          (!self.ignoreUndefined || ret !== undefined)) {
        if (!self.underscoreAssigned) {
          self.last = ret;
        }
        self.output.write(self.writer(ret) + '\n');
      }

      // Display prompt again (unless we already did by emitting the 'error'
      // event on the domain instance).
      if (!e) {
        self.displayPrompt();