@candrewsintegralblue/snyk/dist/cli/22.index.js

snyk library and cli utility

exports.id = 22;
exports.ids = [22];
exports.modules = {

/***/ 9668:
/***/ ((module, __unused_webpack_exports, __webpack_require__) => {

"use strict";


const { Buffer } = __webpack_require__(14300)
const symbol = Symbol.for('BufferList')

function BufferList (buf) {
  if (!(this instanceof BufferList)) {
    return new BufferList(buf)
  }

  BufferList._init.call(this, buf)
}

BufferList._init = function _init (buf) {
  Object.defineProperty(this, symbol, { value: true })

  this._bufs = []
  this.length = 0

  if (buf) {
    this.append(buf)
  }
}

BufferList.prototype._new = function _new (buf) {
  return new BufferList(buf)
}

BufferList.prototype._offset = function _offset (offset) {
  if (offset === 0) {
    return [0, 0]
  }

  let tot = 0

  for (let i = 0; i < this._bufs.length; i++) {
    const _t = tot + this._bufs[i].length
    if (offset < _t || i === this._bufs.length - 1) {
      return [i, offset - tot]
    }
    tot = _t
  }
}

BufferList.prototype._reverseOffset = function (blOffset) {
  const bufferId = blOffset[0]
  let offset = blOffset[1]

  for (let i = 0; i < bufferId; i++) {
    offset += this._bufs[i].length
  }

  return offset
}

BufferList.prototype.get = function get (index) {
  if (index > this.length || index < 0) {
    return undefined
  }

  const offset = this._offset(index)

  return this._bufs[offset[0]][offset[1]]
}

BufferList.prototype.slice = function slice (start, end) {
  if (typeof start === 'number' && start < 0) {
    start += this.length
  }

  if (typeof end === 'number' && end < 0) {
    end += this.length
  }

  return this.copy(null, 0, start, end)
}

BufferList.prototype.copy = function copy (dst, dstStart, srcStart, srcEnd) {
  if (typeof srcStart !== 'number' || srcStart < 0) {
    srcStart = 0
  }

  if (typeof srcEnd !== 'number' || srcEnd > this.length) {
    srcEnd = this.length
  }

  if (srcStart >= this.length) {
    return dst || Buffer.alloc(0)
  }

  if (srcEnd <= 0) {
    return dst || Buffer.alloc(0)
  }

  const copy = !!dst
  const off = this._offset(srcStart)
  const len = srcEnd - srcStart
  let bytes = len
  let bufoff = (copy && dstStart) || 0
  let start = off[1]

  // copy/slice everything
  if (srcStart === 0 && srcEnd === this.length) {
    if (!copy) {
      // slice, but full concat if multiple buffers
      return this._bufs.length === 1
        ? this._bufs[0]
        : Buffer.concat(this._bufs, this.length)
    }

    // copy, need to copy individual buffers
    for (let i = 0; i < this._bufs.length; i++) {
      this._bufs[i].copy(dst, bufoff)
      bufoff += this._bufs[i].length
    }

    return dst
  }

  // easy, cheap case where it's a subset of one of the buffers
  if (bytes <= this._bufs[off[0]].length - start) {
    return copy
      ? this._bufs[off[0]].copy(dst, dstStart, start, start + bytes)
      : this._bufs[off[0]].slice(start, start + bytes)
  }

  if (!copy) {
    // a slice, we need something to copy in to
    dst = Buffer.allocUnsafe(len)
  }

  for (let i = off[0]; i < this._bufs.length; i++) {
    const l = this._bufs[i].length - start

    if (bytes > l) {
      this._bufs[i].copy(dst, bufoff, start)
      bufoff += l
    } else {
      this._bufs[i].copy(dst, bufoff, start, start + bytes)
      bufoff += l
      break
    }

    bytes -= l

    if (start) {
      start = 0
    }
  }

  // safeguard so that we don't return uninitialized memory
  if (dst.length > bufoff) return dst.slice(0, bufoff)

  return dst
}

BufferList.prototype.shallowSlice = function shallowSlice (start, end) {
  start = start || 0
  end = typeof end !== 'number' ? this.length : end

  if (start < 0) {
    start += this.length
  }

  if (end < 0) {
    end += this.length
  }

  if (start === end) {
    return this._new()
  }

  const startOffset = this._offset(start)
  const endOffset = this._offset(end)
  const buffers = this._bufs.slice(startOffset[0], endOffset[0] + 1)

  if (endOffset[1] === 0) {
    buffers.pop()
  } else {
    buffers[buffers.length - 1] = buffers[buffers.length - 1].slice(0, endOffset[1])
  }

  if (startOffset[1] !== 0) {
    buffers[0] = buffers[0].slice(startOffset[1])
  }

  return this._new(buffers)
}

BufferList.prototype.toString = function toString (encoding, start, end) {
  return this.slice(start, end).toString(encoding)
}

BufferList.prototype.consume = function consume (bytes) {
  // first, normalize the argument, in accordance with how Buffer does it
  bytes = Math.trunc(bytes)
  // do nothing if not a positive number
  if (Number.isNaN(bytes) || bytes <= 0) return this

  while (this._bufs.length) {
    if (bytes >= this._bufs[0].length) {
      bytes -= this._bufs[0].length
      this.length -= this._bufs[0].length
      this._bufs.shift()
    } else {
      this._bufs[0] = this._bufs[0].slice(bytes)
      this.length -= bytes
      break
    }
  }

  return this
}

BufferList.prototype.duplicate = function duplicate () {
  const copy = this._new()

  for (let i = 0; i < this._bufs.length; i++) {
    copy.append(this._bufs[i])
  }

  return copy
}

BufferList.prototype.append = function append (buf) {
  if (buf == null) {
    return this
  }

  if (buf.buffer) {
    // append a view of the underlying ArrayBuffer
    this._appendBuffer(Buffer.from(buf.buffer, buf.byteOffset, buf.byteLength))
  } else if (Array.isArray(buf)) {
    for (let i = 0; i < buf.length; i++) {
      this.append(buf[i])
    }
  } else if (this._isBufferList(buf)) {
    // unwrap argument into individual BufferLists
    for (let i = 0; i < buf._bufs.length; i++) {
      this.append(buf._bufs[i])
    }
  } else {
    // coerce number arguments to strings, since Buffer(number) does
    // uninitialized memory allocation
    if (typeof buf === 'number') {
      buf = buf.toString()
    }

    this._appendBuffer(Buffer.from(buf))
  }

  return this
}

BufferList.prototype._appendBuffer = function appendBuffer (buf) {
  this._bufs.push(buf)
  this.length += buf.length
}

BufferList.prototype.indexOf = function (search, offset, encoding) {
  if (encoding === undefined && typeof offset === 'string') {
    encoding = offset
    offset = undefined
  }

  if (typeof search === 'function' || Array.isArray(search)) {
    throw new TypeError('The "value" argument must be one of type string, Buffer, BufferList, or Uint8Array.')
  } else if (typeof search === 'number') {
    search = Buffer.from([search])
  } else if (typeof search === 'string') {
    search = Buffer.from(search, encoding)
  } else if (this._isBufferList(search)) {
    search = search.slice()
  } else if (Array.isArray(search.buffer)) {
    search = Buffer.from(search.buffer, search.byteOffset, search.byteLength)
  } else if (!Buffer.isBuffer(search)) {
    search = Buffer.from(search)
  }

  offset = Number(offset || 0)

  if (isNaN(offset)) {
    offset = 0
  }

  if (offset < 0) {
    offset = this.length + offset
  }

  if (offset < 0) {
    offset = 0
  }

  if (search.length === 0) {
    return offset > this.length ? this.length : offset
  }

  const blOffset = this._offset(offset)
  let blIndex = blOffset[0] // index of which internal buffer we're working on
  let buffOffset = blOffset[1] // offset of the internal buffer we're working on

  // scan over each buffer
  for (; blIndex < this._bufs.length; blIndex++) {
    const buff = this._bufs[blIndex]

    while (buffOffset < buff.length) {
      const availableWindow = buff.length - buffOffset

      if (availableWindow >= search.length) {
        const nativeSearchResult = buff.indexOf(search, buffOffset)

        if (nativeSearchResult !== -1) {
          return this._reverseOffset([blIndex, nativeSearchResult])
        }

        buffOffset = buff.length - search.length + 1 // end of native search window
      } else {
        const revOffset = this._reverseOffset([blIndex, buffOffset])

        if (this._match(revOffset, search)) {
          return revOffset
        }

        buffOffset++
      }
    }

    buffOffset = 0
  }

  return -1
}

BufferList.prototype._match = function (offset, search) {
  if (this.length - offset < search.length) {
    return false
  }

  for (let searchOffset = 0; searchOffset < search.length; searchOffset++) {
    if (this.get(offset + searchOffset) !== search[searchOffset]) {
      return false
    }
  }
  return true
}

;(function () {
  const methods = {
    readDoubleBE: 8,
    readDoubleLE: 8,
    readFloatBE: 4,
    readFloatLE: 4,
    readInt32BE: 4,
    readInt32LE: 4,
    readUInt32BE: 4,
    readUInt32LE: 4,
    readInt16BE: 2,
    readInt16LE: 2,
    readUInt16BE: 2,
    readUInt16LE: 2,
    readInt8: 1,
    readUInt8: 1,
    readIntBE: null,
    readIntLE: null,
    readUIntBE: null,
    readUIntLE: null
  }

  for (const m in methods) {
    (function (m) {
      if (methods[m] === null) {
        BufferList.prototype[m] = function (offset, byteLength) {
          return this.slice(offset, offset + byteLength)[m](0, byteLength)
        }
      } else {
        BufferList.prototype[m] = function (offset = 0) {
          return this.slice(offset, offset + methods[m])[m](0)
        }
      }
    }(m))
  }
}())

// Used internally by the class and also as an indicator of this object being
// a `BufferList`. It's not possible to use `instanceof BufferList` in a browser
// environment because there could be multiple different copies of the
// BufferList class and some `BufferList`s might be `BufferList`s.
BufferList.prototype._isBufferList = function _isBufferList (b) {
  return b instanceof BufferList || BufferList.isBufferList(b)
}

BufferList.isBufferList = function isBufferList (b) {
  return b != null && b[symbol]
}

module.exports = BufferList


/***/ }),

/***/ 10022:
/***/ ((module, __unused_webpack_exports, __webpack_require__) => {

"use strict";


const DuplexStream = __webpack_require__(11451).Duplex
const inherits = __webpack_require__(94378)
const BufferList = __webpack_require__(9668)

function BufferListStream (callback) {
  if (!(this instanceof BufferListStream)) {
    return new BufferListStream(callback)
  }

  if (typeof callback === 'function') {
    this._callback = callback

    const piper = function piper (err) {
      if (this._callback) {
        this._callback(err)
        this._callback = null
      }
    }.bind(this)

    this.on('pipe', function onPipe (src) {
      src.on('error', piper)
    })
    this.on('unpipe', function onUnpipe (src) {
      src.removeListener('error', piper)
    })

    callback = null
  }

  BufferList._init.call(this, callback)
  DuplexStream.call(this)
}

inherits(BufferListStream, DuplexStream)
Object.assign(BufferListStream.prototype, BufferList.prototype)

BufferListStream.prototype._new = function _new (callback) {
  return new BufferListStream(callback)
}

BufferListStream.prototype._write = function _write (buf, encoding, callback) {
  this._appendBuffer(buf)

  if (typeof callback === 'function') {
    callback()
  }
}

BufferListStream.prototype._read = function _read (size) {
  if (!this.length) {
    return this.push(null)
  }

  size = Math.min(size, this.length)
  this.push(this.slice(0, size))
  this.consume(size)
}

BufferListStream.prototype.end = function end (chunk) {
  DuplexStream.prototype.end.call(this, chunk)

  if (this._callback) {
    this._callback(null, this.slice())
    this._callback = null
  }
}

BufferListStream.prototype._destroy = function _destroy (err, cb) {
  this._bufs.length = 0
  this.length = 0
  cb(err)
}

BufferListStream.prototype._isBufferList = function _isBufferList (b) {
  return b instanceof BufferListStream || b instanceof BufferList || BufferListStream.isBufferList(b)
}

BufferListStream.isBufferList = BufferList.isBufferList

module.exports = BufferListStream
module.exports.BufferListStream = BufferListStream
module.exports.BufferList = BufferList


/***/ }),

/***/ 94378:
/***/ ((module, __unused_webpack_exports, __webpack_require__) => {

try {
  var util = __webpack_require__(73837);
  /* istanbul ignore next */
  if (typeof util.inherits !== 'function') throw '';
  module.exports = util.inherits;
} catch (e) {
  /* istanbul ignore next */
  module.exports = __webpack_require__(35717);
}


/***/ }),

/***/ 35717:
/***/ ((module) => {

if (typeof Object.create === 'function') {
  // implementation from standard node.js 'util' module
  module.exports = function inherits(ctor, superCtor) {
    if (superCtor) {
      ctor.super_ = superCtor
      ctor.prototype = Object.create(superCtor.prototype, {
        constructor: {
          value: ctor,
          enumerable: false,
          writable: true,
          configurable: true
        }
      })
    }
  };
} else {
  // old school shim for old browsers
  module.exports = function inherits(ctor, superCtor) {
    if (superCtor) {
      ctor.super_ = superCtor
      var TempCtor = function () {}
      TempCtor.prototype = superCtor.prototype
      ctor.prototype = new TempCtor()
      ctor.prototype.constructor = ctor
    }
  }
}


/***/ }),

/***/ 4012:
/***/ ((module) => {

"use strict";


const codes = {};

function createErrorType(code, message, Base) {
  if (!Base) {
    Base = Error
  }

  function getMessage (arg1, arg2, arg3) {
    if (typeof message === 'string') {
      return message
    } else {
      return message(arg1, arg2, arg3)
    }
  }

  class NodeError extends Base {
    constructor (arg1, arg2, arg3) {
      super(getMessage(arg1, arg2, arg3));
    }
  }

  NodeError.prototype.name = Base.name;
  NodeError.prototype.code = code;

  codes[code] = NodeError;
}

// https://github.com/nodejs/node/blob/v10.8.0/lib/internal/errors.js
function oneOf(expected, thing) {
  if (Array.isArray(expected)) {
    const len = expected.length;
    expected = expected.map((i) => String(i));
    if (len > 2) {
      return `one of ${thing} ${expected.slice(0, len - 1).join(', ')}, or ` +
             expected[len - 1];
    } else if (len === 2) {
      return `one of ${thing} ${expected[0]} or ${expected[1]}`;
    } else {
      return `of ${thing} ${expected[0]}`;
    }
  } else {
    return `of ${thing} ${String(expected)}`;
  }
}

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/startsWith
function startsWith(str, search, pos) {
	return str.substr(!pos || pos < 0 ? 0 : +pos, search.length) === search;
}

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/endsWith
function endsWith(str, search, this_len) {
	if (this_len === undefined || this_len > str.length) {
		this_len = str.length;
	}
	return str.substring(this_len - search.length, this_len) === search;
}

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/includes
function includes(str, search, start) {
  if (typeof start !== 'number') {
    start = 0;
  }

  if (start + search.length > str.length) {
    return false;
  } else {
    return str.indexOf(search, start) !== -1;
  }
}

createErrorType('ERR_INVALID_OPT_VALUE', function (name, value) {
  return 'The value "' + value + '" is invalid for option "' + name + '"'
}, TypeError);
createErrorType('ERR_INVALID_ARG_TYPE', function (name, expected, actual) {
  // determiner: 'must be' or 'must not be'
  let determiner;
  if (typeof expected === 'string' && startsWith(expected, 'not ')) {
    determiner = 'must not be';
    expected = expected.replace(/^not /, '');
  } else {
    determiner = 'must be';
  }

  let msg;
  if (endsWith(name, ' argument')) {
    // For cases like 'first argument'
    msg = `The ${name} ${determiner} ${oneOf(expected, 'type')}`;
  } else {
    const type = includes(name, '.') ? 'property' : 'argument';
    msg = `The "${name}" ${type} ${determiner} ${oneOf(expected, 'type')}`;
  }

  msg += `. Received type ${typeof actual}`;
  return msg;
}, TypeError);
createErrorType('ERR_STREAM_PUSH_AFTER_EOF', 'stream.push() after EOF');
createErrorType('ERR_METHOD_NOT_IMPLEMENTED', function (name) {
  return 'The ' + name + ' method is not implemented'
});
createErrorType('ERR_STREAM_PREMATURE_CLOSE', 'Premature close');
createErrorType('ERR_STREAM_DESTROYED', function (name) {
  return 'Cannot call ' + name + ' after a stream was destroyed';
});
createErrorType('ERR_MULTIPLE_CALLBACK', 'Callback called multiple times');
createErrorType('ERR_STREAM_CANNOT_PIPE', 'Cannot pipe, not readable');
createErrorType('ERR_STREAM_WRITE_AFTER_END', 'write after end');
createErrorType('ERR_STREAM_NULL_VALUES', 'May not write null values to stream', TypeError);
createErrorType('ERR_UNKNOWN_ENCODING', function (arg) {
  return 'Unknown encoding: ' + arg
}, TypeError);
createErrorType('ERR_STREAM_UNSHIFT_AFTER_END_EVENT', 'stream.unshift() after end event');

module.exports.q = codes;


/***/ }),

/***/ 56753:
/***/ ((module, __unused_webpack_exports, __webpack_require__) => {

"use strict";
// 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 duplex stream is just a stream that is both readable and writable.
// Since JS doesn't have multiple prototypal inheritance, this class
// prototypally inherits from Readable, and then parasitically from
// Writable.

/*<replacement>*/

var objectKeys = Object.keys || function (obj) {
  var keys = [];

  for (var key in obj) {
    keys.push(key);
  }

  return keys;
};
/*</replacement>*/


module.exports = Duplex;

var Readable = __webpack_require__(79481);

var Writable = __webpack_require__(64229);

__webpack_require__(94378)(Duplex, Readable);

{
  // Allow the keys array to be GC'ed.
  var keys = objectKeys(Writable.prototype);

  for (var v = 0; v < keys.length; v++) {
    var method = keys[v];
    if (!Duplex.prototype[method]) Duplex.prototype[method] = Writable.prototype[method];
  }
}

function Duplex(options) {
  if (!(this instanceof Duplex)) return new Duplex(options);
  Readable.call(this, options);
  Writable.call(this, options);
  this.allowHalfOpen = true;

  if (options) {
    if (options.readable === false) this.readable = false;
    if (options.writable === false) this.writable = false;

    if (options.allowHalfOpen === false) {
      this.allowHalfOpen = false;
      this.once('end', onend);
    }
  }
}

Object.defineProperty(Duplex.prototype, 'writableHighWaterMark', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._writableState.highWaterMark;
  }
});
Object.defineProperty(Duplex.prototype, 'writableBuffer', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._writableState && this._writableState.getBuffer();
  }
});
Object.defineProperty(Duplex.prototype, 'writableLength', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    return this._writableState.length;
  }
}); // the no-half-open enforcer

function onend() {
  // If the writable side ended, then we're ok.
  if (this._writableState.ended) return; // no more data can be written.
  // But allow more writes to happen in this tick.

  process.nextTick(onEndNT, this);
}

function onEndNT(self) {
  self.end();
}

Object.defineProperty(Duplex.prototype, 'destroyed', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    if (this._readableState === undefined || this._writableState === undefined) {
      return false;
    }

    return this._readableState.destroyed && this._writableState.destroyed;
  },
  set: function set(value) {
    // we ignore the value if the stream
    // has not been initialized yet
    if (this._readableState === undefined || this._writableState === undefined) {
      return;
    } // backward compatibility, the user is explicitly
    // managing destroyed


    this._readableState.destroyed = value;
    this._writableState.destroyed = value;
  }
});

/***/ }),

/***/ 82725:
/***/ ((module, __unused_webpack_exports, __webpack_require__) => {

"use strict";
// 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 passthrough stream.
// basically just the most minimal sort of Transform stream.
// Every written chunk gets output as-is.


module.exports = PassThrough;

var Transform = __webpack_require__(74605);

__webpack_require__(94378)(PassThrough, Transform);

function PassThrough(options) {
  if (!(this instanceof PassThrough)) return new PassThrough(options);
  Transform.call(this, options);
}

PassThrough.prototype._transform = function (chunk, encoding, cb) {
  cb(null, chunk);
};

/***/ }),

/***/ 79481:
/***/ ((module, __unused_webpack_exports, __webpack_require__) => {

"use strict";
// 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.


module.exports = Readable;
/*<replacement>*/

var Duplex;
/*</replacement>*/

Readable.ReadableState = ReadableState;
/*<replacement>*/

var EE = __webpack_require__(82361).EventEmitter;

var EElistenerCount = function EElistenerCount(emitter, type) {
  return emitter.listeners(type).length;
};
/*</replacement>*/

/*<replacement>*/


var Stream = __webpack_require__(79740);
/*</replacement>*/


var Buffer = __webpack_require__(14300).Buffer;

var OurUint8Array = global.Uint8Array || function () {};

function _uint8ArrayToBuffer(chunk) {
  return Buffer.from(chunk);
}

function _isUint8Array(obj) {
  return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
}
/*<replacement>*/


var debugUtil = __webpack_require__(73837);

var debug;

if (debugUtil && debugUtil.debuglog) {
  debug = debugUtil.debuglog('stream');
} else {
  debug = function debug() {};
}
/*</replacement>*/


var BufferList = __webpack_require__(57327);

var destroyImpl = __webpack_require__(61195);

var _require = __webpack_require__(82457),
    getHighWaterMark = _require.getHighWaterMark;

var _require$codes = __webpack_require__(4012)/* .codes */ .q,
    ERR_INVALID_ARG_TYPE = _require$codes.ERR_INVALID_ARG_TYPE,
    ERR_STREAM_PUSH_AFTER_EOF = _require$codes.ERR_STREAM_PUSH_AFTER_EOF,
    ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
    ERR_STREAM_UNSHIFT_AFTER_END_EVENT = _require$codes.ERR_STREAM_UNSHIFT_AFTER_END_EVENT; // Lazy loaded to improve the startup performance.


var StringDecoder;
var createReadableStreamAsyncIterator;
var from;

__webpack_require__(94378)(Readable, Stream);

var errorOrDestroy = destroyImpl.errorOrDestroy;
var kProxyEvents = ['error', 'close', 'destroy', 'pause', 'resume'];

function prependListener(emitter, event, fn) {
  // Sadly this is not cacheable as some libraries bundle their own
  // event emitter implementation with them.
  if (typeof emitter.prependListener === 'function') return emitter.prependListener(event, fn); // This is a hack to make sure that our error handler is attached before any
  // userland ones.  NEVER DO THIS. This is here only because this code needs
  // to continue to work with older versions of Node.js that do not include
  // the prependListener() method. The goal is to eventually remove this hack.

  if (!emitter._events || !emitter._events[event]) emitter.on(event, fn);else if (Array.isArray(emitter._events[event])) emitter._events[event].unshift(fn);else emitter._events[event] = [fn, emitter._events[event]];
}

function ReadableState(options, stream, isDuplex) {
  Duplex = Duplex || __webpack_require__(56753);
  options = options || {}; // Duplex streams are both readable and writable, but share
  // the same options object.
  // However, some cases require setting options to different
  // values for the readable and the writable sides of the duplex stream.
  // These options can be provided separately as readableXXX and writableXXX.

  if (typeof isDuplex !== 'boolean') isDuplex = stream instanceof Duplex; // object stream flag. Used to make read(n) ignore n and to
  // make all the buffer merging and length checks go away

  this.objectMode = !!options.objectMode;
  if (isDuplex) this.objectMode = this.objectMode || !!options.readableObjectMode; // the point at which it stops calling _read() to fill the buffer
  // Note: 0 is a valid value, means "don't call _read preemptively ever"

  this.highWaterMark = getHighWaterMark(this, options, 'readableHighWaterMark', isDuplex); // A linked list is used to store data chunks instead of an array because the
  // linked list can remove elements from the beginning faster than
  // array.shift()

  this.buffer = new BufferList();
  this.length = 0;
  this.pipes = null;
  this.pipesCount = 0;
  this.flowing = null;
  this.ended = false;
  this.endEmitted = false;
  this.reading = false; // a flag to be able to tell if the event 'readable'/'data' is emitted
  // immediately, or on a later tick.  We set this to true at first, because
  // any actions that shouldn't happen until "later" should generally also
  // not happen before the first read call.

  this.sync = true; // whenever we return null, then we set a flag to say
  // that we're awaiting a 'readable' event emission.

  this.needReadable = false;
  this.emittedReadable = false;
  this.readableListening = false;
  this.resumeScheduled = false;
  this.paused = true; // Should close be emitted on destroy. Defaults to true.

  this.emitClose = options.emitClose !== false; // Should .destroy() be called after 'end' (and potentially 'finish')

  this.autoDestroy = !!options.autoDestroy; // has it been destroyed

  this.destroyed = false; // Crypto is kind of old and crusty.  Historically, its default string
  // encoding is 'binary' so we have to make this configurable.
  // Everything else in the universe uses 'utf8', though.

  this.defaultEncoding = options.defaultEncoding || 'utf8'; // the number of writers that are awaiting a drain event in .pipe()s

  this.awaitDrain = 0; // if true, a maybeReadMore has been scheduled

  this.readingMore = false;
  this.decoder = null;
  this.encoding = null;

  if (options.encoding) {
    if (!StringDecoder) StringDecoder = __webpack_require__(32553)/* .StringDecoder */ .s;
    this.decoder = new StringDecoder(options.encoding);
    this.encoding = options.encoding;
  }
}

function Readable(options) {
  Duplex = Duplex || __webpack_require__(56753);
  if (!(this instanceof Readable)) return new Readable(options); // Checking for a Stream.Duplex instance is faster here instead of inside
  // the ReadableState constructor, at least with V8 6.5

  var isDuplex = this instanceof Duplex;
  this._readableState = new ReadableState(options, this, isDuplex); // legacy

  this.readable = true;

  if (options) {
    if (typeof options.read === 'function') this._read = options.read;
    if (typeof options.destroy === 'function') this._destroy = options.destroy;
  }

  Stream.call(this);
}

Object.defineProperty(Readable.prototype, 'destroyed', {
  // making it explicit this property is not enumerable
  // because otherwise some prototype manipulation in
  // userland will fail
  enumerable: false,
  get: function get() {
    if (this._readableState === undefined) {
      return false;
    }

    return this._readableState.destroyed;
  },
  set: function set(value) {
    // we ignore the value if the stream
    // has not been initialized yet
    if (!this._readableState) {
      return;
    } // backward compatibility, the user is explicitly
    // managing destroyed


    this._readableState.destroyed = value;
  }
});
Readable.prototype.destroy = destroyImpl.destroy;
Readable.prototype._undestroy = destroyImpl.undestroy;

Readable.prototype._destroy = function (err, cb) {
  cb(err);
}; // Manually shove something into the read() buffer.
// This returns true if the highWaterMark has not been hit yet,
// similar to how Writable.write() returns true if you should
// write() some more.


Readable.prototype.push = function (chunk, encoding) {
  var state = this._readableState;
  var skipChunkCheck;

  if (!state.objectMode) {
    if (typeof chunk === 'string') {
      encoding = encoding || state.defaultEncoding;

      if (encoding !== state.encoding) {
        chunk = Buffer.from(chunk, encoding);
        encoding = '';
      }

      skipChunkCheck = true;
    }
  } else {
    skipChunkCheck = true;
  }

  return readableAddChunk(this, chunk, encoding, false, skipChunkCheck);
}; // Unshift should *always* be something directly out of read()


Readable.prototype.unshift = function (chunk) {
  return readableAddChunk(this, chunk, null, true, false);
};

function readableAddChunk(stream, chunk, encoding, addToFront, skipChunkCheck) {
  debug('readableAddChunk', chunk);
  var state = stream._readableState;

  if (chunk === null) {
    state.reading = false;
    onEofChunk(stream, state);
  } else {
    var er;
    if (!skipChunkCheck) er = chunkInvalid(state, chunk);

    if (er) {
      errorOrDestroy(stream, er);
    } else if (state.objectMode || chunk && chunk.length > 0) {
      if (typeof chunk !== 'string' && !state.objectMode && Object.getPrototypeOf(chunk) !== Buffer.prototype) {
        chunk = _uint8ArrayToBuffer(chunk);
      }

      if (addToFront) {
        if (state.endEmitted) errorOrDestroy(stream, new ERR_STREAM_UNSHIFT_AFTER_END_EVENT());else addChunk(stream, state, chunk, true);
      } else if (state.ended) {
        errorOrDestroy(stream, new ERR_STREAM_PUSH_AFTER_EOF());
      } else if (state.destroyed) {
        return false;
      } else {
        state.reading = false;

        if (state.decoder && !encoding) {
          chunk = state.decoder.write(chunk);
          if (state.objectMode || chunk.length !== 0) addChunk(stream, state, chunk, false);else maybeReadMore(stream, state);
        } else {
          addChunk(stream, state, chunk, false);
        }
      }
    } else if (!addToFront) {
      state.reading = false;
      maybeReadMore(stream, state);
    }
  } // We can push more data if we are below the highWaterMark.
  // Also, if we have no data yet, we can stand some more bytes.
  // This is to work around cases where hwm=0, such as the repl.


  return !state.ended && (state.length < state.highWaterMark || state.length === 0);
}

function addChunk(stream, state, chunk, addToFront) {
  if (state.flowing && state.length === 0 && !state.sync) {
    state.awaitDrain = 0;
    stream.emit('data', chunk);
  } else {
    // update the buffer info.
    state.length += state.objectMode ? 1 : chunk.length;
    if (addToFront) state.buffer.unshift(chunk);else state.buffer.push(chunk);
    if (state.needReadable) emitReadable(stream);
  }

  maybeReadMore(stream, state);
}

function chunkInvalid(state, chunk) {
  var er;

  if (!_isUint8Array(chunk) && typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) {
    er = new ERR_INVALID_ARG_TYPE('chunk', ['string', 'Buffer', 'Uint8Array'], chunk);
  }

  return er;
}

Readable.prototype.isPaused = function () {
  return this._readableState.flowing === false;
}; // backwards compatibility.


Readable.prototype.setEncoding = function (enc) {
  if (!StringDecoder) StringDecoder = __webpack_require__(32553)/* .StringDecoder */ .s;
  var decoder = new StringDecoder(enc);
  this._readableState.decoder = decoder; // If setEncoding(null), decoder.encoding equals utf8

  this._readableState.encoding = this._readableState.decoder.encoding; // Iterate over current buffer to convert already stored Buffers:

  var p = this._readableState.buffer.head;
  var content = '';

  while (p !== null) {
    content += decoder.write(p.data);
    p = p.next;
  }

  this._readableState.buffer.clear();

  if (content !== '') this._readableState.buffer.push(content);
  this._readableState.length = content.length;
  return this;
}; // Don't raise the hwm > 1GB


var MAX_HWM = 0x40000000;

function computeNewHighWaterMark(n) {
  if (n >= MAX_HWM) {
    // TODO(ronag): Throw ERR_VALUE_OUT_OF_RANGE.
    n = MAX_HWM;
  } else {
    // Get the next highest power of 2 to prevent increasing hwm excessively in
    // tiny amounts
    n--;
    n |= n >>> 1;
    n |= n >>> 2;
    n |= n >>> 4;
    n |= n >>> 8;
    n |= n >>> 16;
    n++;
  }

  return n;
} // This function is designed to be inlinable, so please take care when making
// changes to the function body.


function howMuchToRead(n, state) {
  if (n <= 0 || state.length === 0 && state.ended) return 0;
  if (state.objectMode) return 1;

  if (n !== n) {
    // Only flow one buffer at a time
    if (state.flowing && state.length) return state.buffer.head.data.length;else return state.length;
  } // If we're asking for more than the current hwm, then raise the hwm.


  if (n > state.highWaterMark) state.highWaterMark = computeNewHighWaterMark(n);
  if (n <= state.length) return n; // Don't have enough

  if (!state.ended) {
    state.needReadable = true;
    return 0;
  }

  return state.length;
} // you can override either this method, or the async _read(n) below.


Readable.prototype.read = function (n) {
  debug('read', n);
  n = parseInt(n, 10);
  var state = this._readableState;
  var nOrig = n;
  if (n !== 0) state.emittedReadable = false; // if we're doing read(0) to trigger a readable event, but we
  // already have a bunch of data in the buffer, then just trigger
  // the 'readable' event and move on.

  if (n === 0 && state.needReadable && ((state.highWaterMark !== 0 ? state.length >= state.highWaterMark : state.length > 0) || state.ended)) {
    debug('read: emitReadable', state.length, state.ended);
    if (state.length === 0 && state.ended) endReadable(this);else emitReadable(this);
    return null;
  }

  n = howMuchToRead(n, state); // if we've ended, and we're now clear, then finish it up.

  if (n === 0 && state.ended) {
    if (state.length === 0) endReadable(this);
    return null;
  } // All the actual chunk generation logic needs to be
  // *below* the call to _read.  The reason is that in certain
  // synthetic stream cases, such as passthrough streams, _read
  // may be a completely synchronous operation which may change
  // the state of the read buffer, providing enough data when
  // before there was *not* enough.
  //
  // So, the steps are:
  // 1. Figure out what the state of things will be after we do
  // a read from the buffer.
  //
  // 2. If that resulting state will trigger a _read, then call _read.
  // Note that this may be asynchronous, or synchronous.  Yes, it is
  // deeply ugly to write APIs this way, but that still doesn't mean
  // that the Readable class should behave improperly, as streams are
  // designed to be sync/async agnostic.
  // Take note if the _read call is sync or async (ie, if the read call
  // has returned yet), so that we know whether or not it's safe to emit
  // 'readable' etc.
  //
  // 3. Actually pull the requested chunks out of the buffer and return.
  // if we need a readable event, then we need to do some reading.


  var doRead = state.needReadable;
  debug('need readable', doRead); // if we currently have less than the highWaterMark, then also read some

  if (state.length === 0 || state.length - n < state.highWaterMark) {
    doRead = true;
    debug('length less than watermark', doRead);
  } // however, if we've ended, then there's no point, and if we're already
  // reading, then it's unnecessary.


  if (state.ended || state.reading) {
    doRead = false;
    debug('reading or ended', doRead);
  } else if (doRead) {
    debug('do read');
    state.reading = true;
    state.sync = true; // if the length is currently zero, then we *need* a readable event.

    if (state.length === 0) state.needReadable = true; // call internal read method

    this._read(state.highWaterMark);

    state.sync = false; // If _read pushed data synchronously, then `reading` will be false,
    // and we need to re-evaluate how much data we can return to the user.

    if (!state.reading) n = howMuchToRead(nOrig, state);
  }

  var ret;
  if (n > 0) ret = fromList(n, state);else ret = null;

  if (ret === null) {
    state.needReadable = state.length <= state.highWaterMark;
    n = 0;
  } else {
    state.length -= n;
    state.awaitDrain = 0;
  }

  if (state.length === 0) {
    // If we have nothing in the buffer, then we want to know
    // as soon as we *do* get something into the buffer.
    if (!state.ended) state.needReadable = true; // If we tried to read() past the EOF, then emit end on the next tick.

    if (nOrig !== n && state.ended) endReadable(this);
  }

  if (ret !== null) this.emit('data', ret);
  return ret;
};

function onEofChunk(stream, state) {
  debug('onEofChunk');
  if (state.ended) return;

  if (state.decoder) {
    var chunk = state.decoder.end();

    if (chunk && chunk.length) {
      state.buffer.push(chunk);
      state.length += state.objectMode ? 1 : chunk.length;
    }
  }

  state.ended = true;

  if (state.sync) {
    // if we are sync, wait until next tick to emit the data.
    // Otherwise we risk emitting data in the flow()
    // the readable code triggers during a read() call
    emitReadable(stream);
  } else {
    // emit 'readable' now to make sure it gets picked up.
    state.needReadable = false;

    if (!state.emittedReadable) {
      state.emittedReadable = true;
      emitReadable_(stream);
    }
  }
} // Don't emit readable right away in sync mode, because this can trigger
// another read() call => stack overflow.  This way, it might trigger
// a nextTick recursion warning, but that's not so bad.


function emitReadable(stream) {
  var state = stream._readableState;
  debug('emitReadable', state.needReadable, state.emittedReadable);
  state.needReadable = false;

  if (!state.emittedReadable) {
    debug('emitReadable', state.flowing);
    state.emittedReadable = true;
    process.nextTick(emitReadable_, stream);
  }
}

function emitReadable_(stream) {
  var state = stream._readableState;
  debug('emitReadable_', state.destroyed, state.length, state.ended);

  if (!state.destroyed && (state.length || state.ended)) {
    stream.emit('readable');
    state.emittedReadable = false;
  } // The stream needs another readable event if
  // 1. It is not flowing, as the flow mechanism will take
  //    care of it.
  // 2. It is not ended.
  // 3. It is below the highWaterMark, so we can schedule
  //    another readable later.


  state.needReadable = !state.flowing && !state.ended && state.length <= state.highWaterMark;
  flow(stream);
} // at this point, the user has presumably seen the 'readable' event,
// and called read() to consume some data.  that may have triggered
// in turn another _read(n) call, in which case reading = true if
// it's in progress.
// However, if we're not ended, or reading, and the length < hwm,
// then go ahead and try to read some more preemptively.


function maybeReadMore(stream, state) {
  if (!state.readingMore) {
    state.readingMore = true;
    process.nextTick(maybeReadMore_, stream, state);
  }
}

function maybeReadMore_(stream, state) {
  // Attempt to read more data if we should.
  //
  // The conditions for reading more data are (one of):
  // - Not enough data buffered (state.length < state.highWaterMark). The loop
  //   is responsible for filling the buffer with enough data if such data
  //   is available. If highWaterMark is 0 and we are not in the flowing mode
  //   we should _not_ attempt to buffer any extra data. We'll get more data
  //   when the stream consumer calls read() instead.
  // - No data in the buffer, and the stream is in flowing mode. In this mode
  //   the loop below is responsible for ensuring read() is called. Failing to
  //   call read here would abort the flow and there's no other mechanism for
  //   continuing the flow if the stream consumer has just subscribed to the
  //   'data' event.
  //
  // In addition to the above conditions to keep reading data, the following
  // conditions prevent the data from being read:
  // - The stream has ended (state.ended).
  // - There is already a pending 'read' operation (state.reading). This is a
  //   case where the the stream has called the implementation defined _read()
  //   method, but they are processing the call asynchronously and have _not_
  //   called push() with new data. In this case we skip performing more
  //   read()s. The execution ends in this method again after the _read() ends
  //   up calling push() with more data.
  while (!state.reading && !state.ended && (state.length < state.highWaterMark || state.flowing && state.length === 0)) {
    var len = state.length;
    debug('maybeReadMore read 0');
    stream.read(0);
    if (len === state.length) // didn't get any data, stop spinning.
      break;
  }

  state.readingMore = false;
} // abstract method.  to be overridden in specific implementation classes.
// call cb(er, data) where data is <= n in length.
// for virtual (non-string, non-buffer) streams, "length" is somewhat
// arbitrary, and perhaps not very meaningful.


Readable.prototype._read = function (n) {
  errorOrDestroy(this, new ERR_METHOD_NOT_IMPLEMENTED('_read()'));
};

Readable.prototype.pipe = function (dest, pipeOpts) {
  var src = this;
  var state = this._readableState;

  switch (state.pipesCount) {
    case 0:
      state.pipes = dest;
      break;

    case 1:
      state.pipes = [state.pipes, dest];
      break;

    default:
      state.pipes.push(dest);
      break;
  }

  state.pipesCount += 1;
  debug('pipe count=%d opts=%j', state.pipesCount, pipeOpts);
  var doEnd = (!pipeOpts || pipeOpts.end !== false) && dest !== process.stdout && dest !== process.stderr;
  var endFn = doEnd ? onend : unpipe;
  if (state.endEmitted) process.nextTick(endFn);else src.once('end', endFn);
  dest.on('unpipe', onunpipe);

  function onunpipe(readable, unpipeInfo) {
    debug('onunpipe');

    if (readable === src) {
      if (unpipeInfo && unpipeInfo.hasUnpiped === false) {
        unpipeInfo.hasUnpiped = true;
        cleanup();
      }
    }
  }

  function onend() {
    debug('onend');
    dest.end();
  } // when the dest drains, it reduces the awaitDrain counter
  // on the source.  This would be more elegant with a .once()
  // handler in flow(), but adding and removing repeatedly is
  // too slow.


  var ondrain = pipeOnDrain(src);
  dest.on('drain', ondrain);
  var cleanedUp = false;

  function cleanup() {
    debug('cleanup'); // cleanup event handlers once the pipe is broken

    dest.removeListener('close', onclose);
    dest.removeListener('finish', onfinish);
    dest.removeListener('drain', ondrain);
    dest.removeListener('error', onerror);
    dest.removeListener('unpipe', onunpipe);
    src.removeListener('end', onend);
    src.removeListener('end', unpipe);
    src.removeListener('data', ondata);
    cleanedUp = true; // if the reader is waiting for a drain event from this
    // specific writer, then it would cause it to never start
    // flowing again.
    // So, if this is awaiting a drain, then we just call it now.
    // If we don't know, then assume that we are waiting for one.

    if (state.awaitDrain && (!dest._writableState || dest._writableState.needDrain)) ondrain();
  }

  src.on('data', ondata);

  function ondata(chunk) {
    debug('ondata');
    var ret = dest.write(chunk);
    debug('dest.write', ret);

    if (ret === false) {
      // If the user unpiped during `dest.write()`, it is possible
      // to get stuck in a permanently paused state if that write
      // also returned false.
      // => Check whether `dest` is still a piping destination.
      if ((state.pipesCount === 1 && state.pipes === dest || state.pipesCount > 1 && indexOf(state.pipes, dest) !== -1) && !cleanedUp) {
        debug('false write response, pause', state.awaitDrain);
        state.awaitDrain++;
      }

      src.pause();
    }
  } // if the dest has an error, then stop piping into it.
  // however, don't suppress the throwing behavior for this.


  function onerror(er) {
    debug('onerror', er);
    unpipe();
    dest.removeListener('error', onerror);
    if (EElistenerCount(dest, 'error') === 0) errorOrDestroy(dest, er);
  } // Make sure our error handler is attached before userland ones.


  prependListener(dest, 'error', onerror); // Both close and finish should trigger unpipe, but only once.

  function onclose() {
    dest.removeListener('finish', onfinish);
    unpipe();
  }

  dest.once('close', onclose);

  function onfinish() {
    debug('onfinish');
    dest.removeListener('close', onclose);
    unpipe();
  }

  dest.once('finish', onfinish);

  function unpipe() {
    debug('unpipe');
    src.unpipe(dest);
  } // tell the dest that it's being piped to


  dest.emit('pipe', src); // start the flow if it hasn't been started already.

  if (!state.flowing) {
    debug('pipe resume');
    src.resume();
  }

  return dest;
};

function pipeOnDrain(src) {
  return function pipeOnDrainFunctionResult() {
    var state = src._readableState;
    debug('pipeOnDrain', state.awaitDrain);
    if (state.awaitDrain) state.awaitDrain--;

    if (state.awaitDrain === 0 && EElistenerCount(src, 'data')) {
      state.flowing = true;
      flow(src);
    }
  };
}

Readable.prototype.unpipe = function (dest) {
  var state = this._readableState;
  var unpipeInfo = {
    hasUnpiped: false
  }; // if we're not piping anywhere, then do nothing.

  if (state.pipesCount === 0) return this; // just one destination.  most common case.

  if (state.pipesCount === 1) {
    // passed in one, but it's not the right one.
    if (dest && dest !== state.pipes) return this;
    if (!dest) dest = state.pipes; // got a match.

    state.pipes = null;
    state.pipesCount = 0;
    state.flowing = false;
    if (dest) dest.emit('unpipe', this, unpipeInfo);
    return this;
  } // slow case. multiple pipe destinations.


  if (!dest) {
    // remove all.
    var dests = state.pipes;
    var len = state.pipesCount;
    state.pipes = null;
    state.pipesCount = 0;
    state.flowing = false;

    for (var i = 0; i < len; i++) {
      dests[i].emit('unpipe', this, {
        hasUnpiped: false
      });
    }

    return this;
  } // try to find the right one.


  var index = indexOf(state.pipes, dest);
  if (index === -1) return this;
  state.pipes.splice(index, 1);
  state.pipesCount -= 1;
  if (state.pipesCount === 1) state.pipes = state.pipes[0];
  dest.emit('unpipe', this, unpipeInfo);
  return this;
}; // set up data events if they are asked for
// Ensure readable listeners eventually get something


Readable.prototype.on = function (ev, fn) {
  var res = Stream.prototype.on.call(this, ev, fn);
  var state = this._readableState;

  if (ev === 'data') {
    // update readableListening