Merge pull request #926 from littledan/typedarray-constructor-edge-case

* Tests for throwing a TypeError in the TypedArray constructor on a detached buffer

Detached buffer causes an exception
- If it's already detached going into the constructor
- If the byteOffset coercion causes it to be detached

Tests are valid in ES2017

* Test that TypedArray constructor throws when detaching buffer in length calculation

This test is only valid with the PR in tc39/ecma262#852

* Rename files per review

test/built-ins/TypedArrays/buffer-arg-byteoffset-to-number-detachbuffer.js

@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-typedarray-buffer-byteoffset-length
+description: If TypedArray() is passed a detached buffer, throw
+info: >
+  22.2.4.5 TypedArray ( buffer [ , byteOffset [ , length ] ] )
+
+  ...
+  9. If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
+  ...
+includes: [testTypedArray.js, detachArrayBuffer.js]
+---*/
+
+testWithTypedArrayConstructors(function(TA) {
+  var offset = TA.BYTES_PER_ELEMENT;
+  var buffer = new ArrayBuffer(3 * offset);
+  var byteOffset = { valueOf() { $DETACHBUFFER(buffer); return 1; } };
+  assert.throws(TypeError, () => new TA(buffer, byteOffset));
+});

test/built-ins/TypedArrays/buffer-arg-detachedbuffer.js

@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-typedarray-buffer-byteoffset-length
+description: If TypedArray() is passed a detached buffer, throw
+info: >
+  22.2.4.5 TypedArray ( buffer [ , byteOffset [ , length ] ] )
+
+  ...
+  9. If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
+  ...
+includes: [testTypedArray.js, detachArrayBuffer.js]
+---*/
+
+testWithTypedArrayConstructors(function(TA) {
+  var offset = TA.BYTES_PER_ELEMENT;
+  var buffer = new ArrayBuffer(3 * offset);
+  $DETACHBUFFER(buffer);
+  assert.throws(TypeError, () => new TA(buffer));
+});

test/built-ins/TypedArrays/buffer-arg-length-to-number-detachbuffer.js

@@ -0,0 +1,20 @@
+// Copyright (C) 2017 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-typedarray-buffer-byteoffset-length
+description: If TypedArray() is passed a detached buffer, throw
+info: >
+  22.2.4.5 TypedArray ( buffer [ , byteOffset [ , length ] ] )
+
+  ...
+  9. If IsDetachedBuffer(buffer) is true, throw a TypeError exception.
+  ...
+includes: [testTypedArray.js, detachArrayBuffer.js]
+---*/
+
+testWithTypedArrayConstructors(function(TA) {
+  var offset = TA.BYTES_PER_ELEMENT;
+  var buffer = new ArrayBuffer(3 * offset);
+  var length = { valueOf() { $DETACHBUFFER(buffer); return 1; } };
+  assert.throws(TypeError, () => new TA(buffer, 0, length));
+});