Editorial: add cross-links to internal slots

reference-implementation/lib/ReadableStreamBYOBReader-impl.js

@@ -2,24 +2,14 @@
 
 const { newPromise, resolvePromise, rejectPromise, promiseRejectedWith } = require('./helpers/webidl.js');
 const aos = require('./abstract-ops/readable-streams.js');
+const { mixin } = require('./helpers/miscellaneous.js');
+const ReadableStreamGenericReaderImpl = require('./ReadableStreamGenericReader-impl.js').implementation;
 
-exports.implementation = class ReadableStreamBYOBReaderImpl {
+class ReadableStreamBYOBReaderImpl {
   constructor(globalObject, [stream]) {
     aos.SetUpReadableStreamBYOBReader(this, stream);
   }
 
-  get closed() {
-    return this._closedPromise;
-  }
-
-  cancel(reason) {
-    if (this._stream === undefined) {
-      return promiseRejectedWith(readerLockException('cancel'));
-    }
-
-    return aos.ReadableStreamReaderGenericCancel(this, reason);
-  }
-
   read(view) {
     if (view.byteLength === 0) {
       return promiseRejectedWith(new TypeError('view must have non-zero byteLength'));
@@ -53,7 +43,11 @@ exports.implementation = class ReadableStreamBYOBReaderImpl {
 
     aos.ReadableStreamReaderGenericRelease(this);
   }
-};
+}
+
+mixin(ReadableStreamBYOBReaderImpl.prototype, ReadableStreamGenericReaderImpl.prototype);
+
+exports.implementation = ReadableStreamBYOBReaderImpl;
 
 function readerLockException(name) {
   return new TypeError('Cannot ' + name + ' a stream using a released reader');

reference-implementation/lib/ReadableStreamBYOBReader.webidl

@@ -2,9 +2,7 @@
 interface ReadableStreamBYOBReader {
   constructor(ReadableStream stream);
 
-  readonly attribute Promise<void> closed;
-
-  Promise<void> cancel(optional any reason);
   Promise<ReadableStreamBYOBReadResult> read(ArrayBufferView view);
   void releaseLock();
 };
+ReadableStreamBYOBReader includes ReadableStreamGenericReader;

reference-implementation/lib/ReadableStreamDefaultReader-impl.js

@@ -2,24 +2,14 @@
 
 const { newPromise, resolvePromise, rejectPromise, promiseRejectedWith } = require('./helpers/webidl.js');
 const aos = require('./abstract-ops/readable-streams.js');
+const { mixin } = require('./helpers/miscellaneous.js');
+const ReadableStreamGenericReaderImpl = require('./ReadableStreamGenericReader-impl.js').implementation;
 
-exports.implementation = class ReadableStreamDefaultReaderImpl {
+class ReadableStreamDefaultReaderImpl {
   constructor(globalObject, [stream]) {
     aos.SetUpReadableStreamDefaultReader(this, stream);
   }
 
-  get closed() {
-    return this._closedPromise;
-  }
-
-  cancel(reason) {
-    if (this._stream === undefined) {
-      return promiseRejectedWith(readerLockException('cancel'));
-    }
-
-    return aos.ReadableStreamReaderGenericCancel(this, reason);
-  }
-
   read() {
     if (this._stream === undefined) {
       return promiseRejectedWith(readerLockException('read from'));
@@ -47,7 +37,11 @@ exports.implementation = class ReadableStreamDefaultReaderImpl {
 
     aos.ReadableStreamReaderGenericRelease(this);
   }
-};
+}
+
+mixin(ReadableStreamDefaultReaderImpl.prototype, ReadableStreamGenericReaderImpl.prototype);
+
+exports.implementation = ReadableStreamDefaultReaderImpl;
 
 function readerLockException(name) {
   return new TypeError('Cannot ' + name + ' a stream using a released reader');

reference-implementation/lib/ReadableStreamDefaultReader.webidl

@@ -2,9 +2,7 @@
 interface ReadableStreamDefaultReader {
   constructor(ReadableStream stream);
 
-  readonly attribute Promise<void> closed;
-
-  Promise<void> cancel(optional any reason);
   Promise<ReadableStreamDefaultReadResult> read();
   void releaseLock();
 };
+ReadableStreamDefaultReader includes ReadableStreamGenericReader;

reference-implementation/lib/ReadableStreamGenericReader-impl.js

@@ -0,0 +1,22 @@
+'use strict';
+
+const { promiseRejectedWith } = require('./helpers/webidl.js');
+const aos = require('./abstract-ops/readable-streams.js');
+
+exports.implementation = class ReadableStreamGenericReaderImpl {
+  get closed() {
+    return this._closedPromise;
+  }
+
+  cancel(reason) {
+    if (this._stream === undefined) {
+      return promiseRejectedWith(readerLockException('cancel'));
+    }
+
+    return aos.ReadableStreamReaderGenericCancel(this, reason);
+  }
+};
+
+function readerLockException(name) {
+  return new TypeError('Cannot ' + name + ' a stream using a released reader');
+}

reference-implementation/lib/ReadableStreamGenericReader.webidl

@@ -0,0 +1,5 @@
+interface mixin ReadableStreamGenericReader {
+  readonly attribute Promise<void> closed;
+
+  Promise<void> cancel(optional any reason);
+};

reference-implementation/lib/helpers/miscellaneous.js

@@ -11,3 +11,14 @@ exports.rethrowAssertionErrorRejection = e => {
     }, 0);
   }
 };
+
+exports.mixin = (target, source) => {
+  const keys = Reflect.ownKeys(source);
+  for (let i = 0; i < keys.length; ++i) {
+    if (keys[i] in target) {
+      continue;
+    }
+
+    Object.defineProperty(target, keys[i], Object.getOwnPropertyDescriptor(source, keys[i]));
+  }
+};