[Fix] babel's "loose mode" class transform enbrittles BufferList (#428)

```js Object.defineProperty(Object.prototype, util.inspect.custom, { set(v) { throw 'this should not happen inside readable-stream'; } }); ``` With this change, I believe the output will use [[Define]] instead of [[Set]] for https://github.com/nodejs/node/blob/c101251a95cc82142bee4637f8db6cc360a06d82/lib/internal/streams/buffer_list.js#L167, and thus no longer fail when Object.prototype is modified.

Author: ljharb

.babelrc

@@ -13,11 +13,5 @@
  ],
  "debug": true
  }]
- ],
- "plugins": [
- // Included in the preset, but we can't specify per-plugin options there
- ["@babel/plugin-transform-classes", {
- "loose": true
- }]
  ]
 }

README.md

@@ -15,7 +15,7 @@ npm install --save readable-stream
 
 This package is a mirror of the streams implementations in Node.js.
 
-Full documentation may be found on the [Node.js website](https://nodejs.org/dist/v10.18.1/docs/api/stream.html).
+Full documentation may be found on the [Node.js website](https://nodejs.org/dist/v10.19.0/docs/api/stream.html).
 
 If you want to guarantee a stable streams base, regardless of what version of
 Node you, or the users of your libraries are using, use **readable-stream** *only* and avoid the *"stream"* module in Node-core, for background see [this blogpost](http://r.va.gg/2014/06/why-i-dont-use-nodes-core-stream-module.html).

lib/internal/streams/buffer_list.js

@@ -6,6 +6,12 @@ function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { va
 
 function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
 
+function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
+
+function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }
+
+function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); return Constructor; }
+
 var _require = require('buffer'),
  Buffer = _require.Buffer;
 
@@ -22,170 +28,183 @@ module.exports =
 /*#__PURE__*/
 function () {
  function BufferList() {
+ _classCallCheck(this, BufferList);
+
  this.head = null;
  this.tail = null;
  this.length = 0;
  }
 
- var _proto = BufferList.prototype;
-
- _proto.push = function push(v) {
- var entry = {
- data: v,
- next: null
- };
- if (this.length > 0) this.tail.next = entry;else this.head = entry;
- this.tail = entry;
- ++this.length;
- };
-
- _proto.unshift = function unshift(v) {
- var entry = {
- data: v,
- next: this.head
- };
- if (this.length === 0) this.tail = entry;
- this.head = entry;
- ++this.length;
- };
-
- _proto.shift = function shift() {
- if (this.length === 0) return;
- var ret = this.head.data;
- if (this.length === 1) this.head = this.tail = null;else this.head = this.head.next;
- --this.length;
- return ret;
- };
-
- _proto.clear = function clear() {
- this.head = this.tail = null;
- this.length = 0;
- };
-
- _proto.join = function join(s) {
- if (this.length === 0) return '';
- var p = this.head;
- var ret = '' + p.data;
-
- while (p = p.next) {
- ret += s + p.data;
+ _createClass(BufferList, [{
+ key: "push",
+ value: function push(v) {
+ var entry = {
+ data: v,
+ next: null
+ };
+ if (this.length > 0) this.tail.next = entry;else this.head = entry;
+ this.tail = entry;
+ ++this.length;
  }
-
- return ret;
- };
-
- _proto.concat = function concat(n) {
- if (this.length === 0) return Buffer.alloc(0);
- var ret = Buffer.allocUnsafe(n >>> 0);
- var p = this.head;
- var i = 0;
-
- while (p) {
- copyBuffer(p.data, ret, i);
- i += p.data.length;
- p = p.next;
+ }, {
+ key: "unshift",
+ value: function unshift(v) {
+ var entry = {
+ data: v,
+ next: this.head
+ };
+ if (this.length === 0) this.tail = entry;
+ this.head = entry;
+ ++this.length;
  }
-
- return ret;
- } // Consumes a specified amount of bytes or characters from the buffered data.
- ;
-
- _proto.consume = function consume(n, hasStrings) {
- var ret;
-
- if (n < this.head.data.length) {
- // `slice` is the same for buffers and strings.
- ret = this.head.data.slice(0, n);
- this.head.data = this.head.data.slice(n);
- } else if (n === this.head.data.length) {
- // First chunk is a perfect match.
- ret = this.shift();
- } else {
- // Result spans more than one buffer.
- ret = hasStrings ? this._getString(n) : this._getBuffer(n);
+ }, {
+ key: "shift",
+ value: function shift() {
+ if (this.length === 0) return;
+ var ret = this.head.data;
+ if (this.length === 1) this.head = this.tail = null;else this.head = this.head.next;
+ --this.length;
+ return ret;
+ }
+ }, {
+ key: "clear",
+ value: function clear() {
+ this.head = this.tail = null;
+ this.length = 0;
  }
+ }, {
+ key: "join",
+ value: function join(s) {
+ if (this.length === 0) return '';
+ var p = this.head;
+ var ret = '' + p.data;
+
+ while (p = p.next) {
+ ret += s + p.data;
+ }
 
- return ret;
- };
-
- _proto.first = function first() {
- return this.head.data;
- } // Consumes a specified amount of characters from the buffered data.
- ;
-
- _proto._getString = function _getString(n) {
- var p = this.head;
- var c = 1;
- var ret = p.data;
- n -= ret.length;
-
- while (p = p.next) {
- var str = p.data;
- var nb = n > str.length ? str.length : n;
- if (nb === str.length) ret += str;else ret += str.slice(0, n);
- n -= nb;
-
- if (n === 0) {
- if (nb === str.length) {
- ++c;
- if (p.next) this.head = p.next;else this.head = this.tail = null;
- } else {
- this.head = p;
- p.data = str.slice(nb);
- }
+ return ret;
+ }
+ }, {
+ key: "concat",
+ value: function concat(n) {
+ if (this.length === 0) return Buffer.alloc(0);
+ var ret = Buffer.allocUnsafe(n >>> 0);
+ var p = this.head;
+ var i = 0;
+
+ while (p) {
+ copyBuffer(p.data, ret, i);
+ i += p.data.length;
+ p = p.next;
+ }
 
- break;
+ return ret;
+ } // Consumes a specified amount of bytes or characters from the buffered data.
+
+ }, {
+ key: "consume",
+ value: function consume(n, hasStrings) {
+ var ret;
+
+ if (n < this.head.data.length) {
+ // `slice` is the same for buffers and strings.
+ ret = this.head.data.slice(0, n);
+ this.head.data = this.head.data.slice(n);
+ } else if (n === this.head.data.length) {
+ // First chunk is a perfect match.
+ ret = this.shift();
+ } else {
+ // Result spans more than one buffer.
+ ret = hasStrings ? this._getString(n) : this._getBuffer(n);
  }
 
- ++c;
+ return ret;
  }
+ }, {
+ key: "first",
+ value: function first() {
+ return this.head.data;
+ } // Consumes a specified amount of characters from the buffered data.
+
+ }, {
+ key: "_getString",
+ value: function _getString(n) {
+ var p = this.head;
+ var c = 1;
+ var ret = p.data;
+ n -= ret.length;
+
+ while (p = p.next) {
+ var str = p.data;
+ var nb = n > str.length ? str.length : n;
+ if (nb === str.length) ret += str;else ret += str.slice(0, n);
+ n -= nb;
+
+ if (n === 0) {
+ if (nb === str.length) {
+ ++c;
+ if (p.next) this.head = p.next;else this.head = this.tail = null;
+ } else {
+ this.head = p;
+ p.data = str.slice(nb);
+ }
+
+ break;
+ }
 
- this.length -= c;
- return ret;
- } // Consumes a specified amount of bytes from the buffered data.
- ;
-
- _proto._getBuffer = function _getBuffer(n) {
- var ret = Buffer.allocUnsafe(n);
- var p = this.head;
- var c = 1;
- p.data.copy(ret);
- n -= p.data.length;
-
- while (p = p.next) {
- var buf = p.data;
- var nb = n > buf.length ? buf.length : n;
- buf.copy(ret, ret.length - n, 0, nb);
- n -= nb;
-
- if (n === 0) {
- if (nb === buf.length) {
- ++c;
- if (p.next) this.head = p.next;else this.head = this.tail = null;
- } else {
- this.head = p;
- p.data = buf.slice(nb);
+ ++c;
+ }
+
+ this.length -= c;
+ return ret;
+ } // Consumes a specified amount of bytes from the buffered data.
+
+ }, {
+ key: "_getBuffer",
+ value: function _getBuffer(n) {
+ var ret = Buffer.allocUnsafe(n);
+ var p = this.head;
+ var c = 1;
+ p.data.copy(ret);
+ n -= p.data.length;
+
+ while (p = p.next) {
+ var buf = p.data;
+ var nb = n > buf.length ? buf.length : n;
+ buf.copy(ret, ret.length - n, 0, nb);
+ n -= nb;
+
+ if (n === 0) {
+ if (nb === buf.length) {
+ ++c;
+ if (p.next) this.head = p.next;else this.head = this.tail = null;
+ } else {
+ this.head = p;
+ p.data = buf.slice(nb);
+ }
+
+ break;
  }
 
- break;
+ ++c;
  }
 
- ++c;
+ this.length -= c;
+ return ret;
+ } // Make sure the linked list only shows the minimal necessary information.
+
+ }, {
+ key: custom,
+ value: function value(_, options) {
+ return inspect(this, _objectSpread({}, options, {
+ // Only inspect one level.
+ depth: 0,
+ // It should not recurse.
+ customInspect: false
+ }));
  }
-
- this.length -= c;
- return ret;
- } // Make sure the linked list only shows the minimal necessary information.
- ;
-
- _proto[custom] = function (_, options) {
- return inspect(this, _objectSpread({}, options, {
- // Only inspect one level.
- depth: 0,
- // It should not recurse.
- customInspect: false
- }));
- };
+ }]);
 
  return BufferList;
 }();