zlib: fix inheritance of DeflateRaw without classes

lib/internal/util.js

@@ -9,6 +9,7 @@ const { createPromise, promiseResolve, promiseReject } = binding;
 const kArrowMessagePrivateSymbolIndex = binding['arrow_message_private_symbol'];
 const kDecoratedPrivateSymbolIndex = binding['decorated_private_symbol'];
 const noCrypto = !process.versions.openssl;
+const constructor = Symbol('constructor');
 
 function isError(e) {
   return objectToString(e) === '[object Error]' || e instanceof Error;
@@ -146,7 +147,12 @@ function cachedResult(fn) {
 //   B() instanceof B // true
 function createClassWrapper(type) {
   function fn(...args) {
-    return Reflect.construct(type, args, new.target || type);
+    if (this && !new.target && this[constructor]) {
+      this[constructor](...args);
+      return this;
+    } else {
+      return Reflect.construct(type, args, new.target || type);
+    }
   }
   // Mask the wrapper function name and length values
   Object.defineProperties(fn, {
@@ -267,6 +273,7 @@ module.exports = {
   normalizeEncoding,
   objectToString,
   promisify,
+  constructor,
 
   // Symbol used to customize promisify conversion
   customPromisifyArgs: kCustomPromisifyArgsSymbol,

lib/zlib.js

@@ -32,6 +32,7 @@ const kRangeErrorMessage = 'Cannot create final Buffer. It would be larger ' +
 
 const constants = process.binding('constants').zlib;
 const createClassWrapper = internalUtil.createClassWrapper;
+const constructor = internalUtil.constructor;
 
 // translation table for return codes.
 const codes = {
@@ -175,8 +176,17 @@ class Zlib extends Transform {
     opts = opts || {};
     super(opts);
 
-    this.bytesRead = 0;
+    this[constructor](opts, mode);
+  }
 
+  [constructor](opts, mode) {
+    if (!this._readableState) {
+      // this is being called through util.inherits
+      opts = opts || {};
+      Transform.call(this, opts);
+    }
+
+    this.bytesRead = 0;
     this._opts = opts;
     this._chunkSize = opts.chunkSize || constants.Z_DEFAULT_CHUNK;
 
@@ -506,42 +516,70 @@ class Deflate extends Zlib {
   constructor(opts) {
     super(opts, constants.DEFLATE);
   }
+
+  [constructor](opts) {
+    super[constructor](opts, constants.DEFLATE);
+  }
 }
 
 class Inflate extends Zlib {
   constructor(opts) {
     super(opts, constants.INFLATE);
   }
+
+  [constructor](opts) {
+    super[constructor](opts, constants.INFLATE);
+  }
 }
 
 class Gzip extends Zlib {
   constructor(opts) {
     super(opts, constants.GZIP);
   }
+
+  [constructor](opts) {
+    super[constructor](opts, constants.GZIP);
+  }
 }
 
 class Gunzip extends Zlib {
   constructor(opts) {
     super(opts, constants.GUNZIP);
   }
+
+  [constructor](opts) {
+    super[constructor](opts, constants.GUNZIP);
+  }
 }
 
 class DeflateRaw extends Zlib {
   constructor(opts) {
     super(opts, constants.DEFLATERAW);
   }
+
+  [constructor](opts) {
+    super[constructor](opts, constants.DEFLATERAW);
+  }
 }
 
 class InflateRaw extends Zlib {
   constructor(opts) {
     super(opts, constants.INFLATERAW);
   }
+
+  [constructor](opts) {
+    super[constructor](opts, constants.INFLATERAW);
+  }
 }
 
 class Unzip extends Zlib {
   constructor(opts) {
     super(opts, constants.UNZIP);
   }
+
+  [constructor](opts) {
+    super[constructor](opts, constants.UNZIP);
+  }
 }
 
 function createConvenienceMethod(type, sync) {

test/parallel/test-internal-util-classwrapper.js

@@ -4,11 +4,16 @@
 require('../common');
 const assert = require('assert');
 const util = require('internal/util');
+const { inherits } = require('util');
 
 const createClassWrapper = util.createClassWrapper;
 
 class A {
-  constructor(a, b, c) {
+  constructor() {
+    this[util.constructor](...arguments);
+  }
+
+  [util.constructor](a, b, c) {
     this.a = a;
     this.b = b;
     this.c = c;
@@ -17,6 +22,8 @@ class A {
 
 const B = createClassWrapper(A);
 
+B.prototype.func = function() {};
+
 assert.strictEqual(typeof B, 'function');
 assert(B(1, 2, 3) instanceof B);
 assert(B(1, 2, 3) instanceof A);
@@ -29,3 +36,29 @@ const b = new B(1, 2, 3);
 assert.strictEqual(b.a, 1);
 assert.strictEqual(b.b, 2);
 assert.strictEqual(b.c, 3);
+assert.strictEqual(b.func, B.prototype.func);
+
+function C(a, b, c) {
+  if (!(this instanceof C)) {
+    return new C(a, b, c);
+  }
+  B.call(this, a, b, c);
+}
+
+inherits(C, B);
+
+C.prototype.kaboom = function() {};
+
+const c = new C(4, 2, 3);
+assert.strictEqual(c.a, 4);
+assert.strictEqual(c.b, 2);
+assert.strictEqual(c.c, 3);
+assert.strictEqual(c.kaboom, C.prototype.kaboom);
+assert.strictEqual(c.func, B.prototype.func);
+
+const c2 = C(4, 2, 3);
+assert.strictEqual(c2.a, 4);
+assert.strictEqual(c2.b, 2);
+assert.strictEqual(c2.c, 3);
+assert.strictEqual(c2.kaboom, C.prototype.kaboom);
+assert.strictEqual(c2.func, B.prototype.func);

test/parallel/test-zlib-deflate-raw-inherits.js

@@ -0,0 +1,27 @@
+'use strict';
+
+require('../common');
+const zlib = require('zlib');
+const inherits = require('util').inherits;
+const { Readable } = require('stream');
+
+// validates that zlib.DeflateRaw can be inherited
+// with util.inherits
+
+function NotInitialized(options) {
+  zlib.DeflateRaw.call(this, options);
+  this.prop = true;
+}
+inherits(NotInitialized, zlib.DeflateRaw);
+
+const dest = new NotInitialized();
+
+const read = new Readable({
+  read() {
+    this.push(Buffer.from('a test string'));
+    this.push(null);
+  }
+});
+
+read.pipe(dest);
+dest.resume();