Bug 1523562 [wpt PR 14794] - TextDecoderStream: Permit detached buffers, a=testonly

Automatic update from web-platform-tests
TextDecoderStream: Permit detached buffers

Since https://github.com/heycam/webidl/pull/605 converting a chunk to a
BufferSource no longer throws if the chunk is detached. Update the
TextDecoderStream implementation and tests to match the new behaviour.

Change-Id: I26230d9cbfce871b3dae75e612539564d4578977
Reviewed-on: https://chromium-review.googlesource.com/c/1404906
Reviewed-by: Joshua Bell <jsbell@chromium.org>
Commit-Queue: Adam Rice <ricea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#621897}

--

wpt-commits: 35d1ca9cb52f755566ba6681fe555626379b9e2c
wpt-pr: 14794

testing/web-platform/tests/encoding/streams/decode-bad-chunks.any.js

@@ -23,26 +23,6 @@ const badChunks = [
     name: 'array',
     value: [65]
   },
-  {
-    name: 'detached ArrayBufferView',
-    value: (() => {
-      const u8 = new Uint8Array([65]);
-      const ab = u8.buffer;
-      const mc = new MessageChannel();
-      mc.port1.postMessage(ab, [ab]);
-      return u8;
-    })()
-  },
-  {
-    name: 'detached ArrayBuffer',
-    value: (() => {
-      const u8 = new Uint8Array([65]);
-      const ab = u8.buffer;
-      const mc = new MessageChannel();
-      mc.port1.postMessage(ab, [ab]);
-      return ab;
-    })()
-  },
   {
     name: 'SharedArrayBuffer',
     // Use a getter to postpone construction so that all tests don't fail where

testing/web-platform/tests/encoding/streams/decode-utf8.any.js

@@ -39,3 +39,23 @@ promise_test(async () => {
   assert_array_equals(array, [expectedOutputString],
                       'the output should be in one chunk');
 }, 'a trailing empty chunk should be ignored');
+
+promise_test(async () => {
+  const buffer = new ArrayBuffer(3);
+  const view = new Uint8Array(buffer, 1, 1);
+  view[0] = 65;
+  new MessageChannel().port1.postMessage(buffer, [buffer]);
+  const input = readableStreamFromArray([view]);
+  const output = input.pipeThrough(new TextDecoderStream());
+  const array = await readableStreamToArray(output);
+  assert_array_equals(array, [], 'no chunks should be output');
+}, 'decoding a transferred Uint8Array chunk should give no output');
+
+promise_test(async () => {
+  const buffer = new ArrayBuffer(1);
+  new MessageChannel().port1.postMessage(buffer, [buffer]);
+  const input = readableStreamFromArray([buffer]);
+  const output = input.pipeThrough(new TextDecoderStream());
+  const array = await readableStreamToArray(output);
+  assert_array_equals(array, [], 'no chunks should be output');
+}, 'decoding a transferred ArrayBuffer chunk should give no output');