squash! more

index.bs

@@ -869,16 +869,13 @@ for="ReadableStreamAsyncIteratorPrototype">return( <var>value</var> )</h4>
 <emu-alg>
   1. If ! IsReadableStreamAsyncIterator(*this*) is *false*, return <a>a promise rejected with</a> *TypeError* exception.
   1. Let _reader_ be *this*.[[asyncIteratorReader]].
+  1. If _reader_.[[ownerReadableStream]] is *undefined*, return <a>a promise rejected with</a> a *TypeError* exception.
+  1. If _reader_.[[readRequests]] is not empty, return <a>a promise rejected with</a> a *TypeError* exception.
   1. If *this*.[[preventCancel]] is *false*, then:
-    1. If _reader_.[[ownerReadableStream]] is *undefined*, return <a>a promise rejected with</a> a *TypeError*
-    exception.
-    1. If _reader_.[[readRequests]] is not empty, return <a>a promise rejected with</a> a *TypeError* exception.
     1. Let _result_ be ! ReadableStreamReaderGenericCancel(_reader_, _value_).
     1. Perform ! ReadableStreamReaderGenericRelease(_reader_).
     1. Return the result of <a>transforming</a> _result_ by a fulfillment handler that returns !
     ReadableStreamCreateReadResult(_value_, *true*, *true*).
-  1. If _reader_.[[ownerReadableStream]] is *undefined*, return <a>a promise rejected with</a> a *TypeError* exception.
-  1. If _reader_.[[readRequests]] is not empty, return <a>a promise rejected with</a> a *TypeError* exception.
   1. Perform ! ReadableStreamReaderGenericRelease(_reader_).
   1. Return <a>a promise resolved with</a> ! ReadableStreamCreateReadResult(_value_, *true*, *true*).
 </emu-alg>

reference-implementation/lib/readable-stream.js

@@ -179,7 +179,7 @@ const ReadableStreamAsyncIteratorPrototype = Object.setPrototypeOf({
     }
     const reader = this._asyncIteratorReader;
     if (reader._ownerReadableStream === undefined) {
-      return Promise.reject(readerLockException('next'));
+      return Promise.reject(readerLockException('iterate'));
     }
     return ReadableStreamDefaultReaderRead(reader, true);
   },
@@ -189,25 +189,18 @@ const ReadableStreamAsyncIteratorPrototype = Object.setPrototypeOf({
       return Promise.reject(streamAsyncIteratorBrandCheckException('next'));
     }
     const reader = this._asyncIteratorReader;
-    if (this.preventCancel === false) {
-      if (reader._ownerReadableStream === undefined) {
-        return Promise.reject(readerLockException('next'));
-      }
-      if (reader._readRequests.length > 0) {
-        return Promise.reject(new TypeError(
-          'Tried to release a reader lock when that reader has pending read() calls un-settled'));
-      }
-      const result = ReadableStreamReaderGenericCancel(reader, value);
-      ReadableStreamReaderGenericRelease(reader);
-      return result.then(() => ReadableStreamCreateReadResult(value, true, true));
-    }
     if (reader._ownerReadableStream === undefined) {
-      return Promise.reject(readerLockException('next'));
+      return Promise.reject(readerLockException('finish iterating'));
     }
     if (reader._readRequests.length > 0) {
       return Promise.reject(new TypeError(
         'Tried to release a reader lock when that reader has pending read() calls un-settled'));
     }
+    if (this._preventCancel === false) {
+      const result = ReadableStreamReaderGenericCancel(reader, value);
+      ReadableStreamReaderGenericRelease(reader);
+      return result.then(() => ReadableStreamCreateReadResult(value, true, true));
+    }
     ReadableStreamReaderGenericRelease(reader);
     return Promise.resolve(ReadableStreamCreateReadResult(value, true, true));
   }