Fix inspector preview for detached JSTypedArray

R=petermarshall@chromium.org

Bug: chromium:952455
Change-Id: Ib08a20e1d1fac7ef943f15ff524ee4e7c1c15507
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1662290
Commit-Queue: Yang Guo <yangguo@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62261}

src/debug/debug-property-iterator.cc

@@ -148,9 +148,13 @@ void DebugPropertyIterator::FillKeysForCurrentPrototypeAndStage() {
   bool has_exotic_indices = receiver->IsJSTypedArray();
   if (stage_ == kExoticIndices) {
     if (!has_exotic_indices) return;
-    // TODO(bmeurer, v8:4153): Change this to size_t later.
-    exotic_length_ =
-        static_cast<uint32_t>(Handle<JSTypedArray>::cast(receiver)->length());
+    Handle<JSTypedArray> typed_array = Handle<JSTypedArray>::cast(receiver);
+    if (typed_array->WasDetached()) {
+      exotic_length_ = 0;
+    } else {
+      // TODO(bmeurer, v8:4153): Change this to size_t later.
+      exotic_length_ = static_cast<uint32_t>(typed_array->length());
+    }
     return;
   }
   bool skip_indices = has_exotic_indices;

test/inspector/runtime/get-properties-expected.txt

@@ -103,6 +103,16 @@ Running test: testArrayBuffer
   1 own number 16843009
   __proto__ own object undefined
 
+Running test: testDetachedArrayBuffer
+[[Int8Array]]
+  __proto__ own object undefined
+[[Uint8Array]]
+  __proto__ own object undefined
+[[Int16Array]]
+  __proto__ own object undefined
+[[Int32Array]]
+  __proto__ own object undefined
+
 Running test: testArrayBufferWithBrokenUintCtor
   [[Int8Array]] own object undefined
   [[Uint8Array]] own object undefined

test/inspector/runtime/get-properties.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Flags: --harmony-private-fields
+// Flags: --harmony-private-fields --allow-natives-syntax
 
 let {session, contextGroup, Protocol} = InspectorTest.start('Checks Runtime.getProperties method');
 
@@ -52,6 +52,21 @@ InspectorTest.runAsyncTestSuite([
     }
   },
 
+  async function testDetachedArrayBuffer() {
+    await Protocol.Runtime.evaluate({ expression: 'var a = new ArrayBuffer(16)' });
+    await Protocol.Runtime.evaluate({ expression: 'var b = new Uint32Array(a)' });
+    let objectId = await evaluateToObjectId('a');
+    await Protocol.Runtime.evaluate({ expression: '%ArrayBufferDetach(a)' });
+    await Protocol.Runtime.evaluate({ expression: 'b', generatePreview: true })
+    let props = await Protocol.Runtime.getProperties({ objectId, ownProperties: true });
+    for (let prop of props.result.result) {
+      if (prop.name === '__proto__')
+        continue;
+      InspectorTest.log(prop.name);
+      await logGetPropertiesResult(prop.value.objectId);
+    }
+  },
+
   async function testArrayBufferWithBrokenUintCtor() {
     await evaluateToObjectId(`(function() {
       this.uint8array_old = this.Uint8Array;