Resizable ArrayBuffer: TypedArray accessors (#3028)

* Add "feature" for "Resizable ArrayBuffer" proposal

* Resizable ArrayBuffer: TypedArray accessors

test/built-ins/TypedArray/prototype/byteLength/resizable-array-buffer-auto.js

@@ -0,0 +1,46 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-get-%typedarray%.prototype.byteoffset
+description: |
+  reset to 0 if the underlying ArrayBuffer is resized beyond the boundary of
+  the dynamically-sized TypedArray instance
+includes: [testTypedArray.js]
+features: [TypedArray, resizable-arraybuffer]
+---*/
+
+// If the host chooses to throw as allowed by the specification, the observed
+// behavior will be identical to the case where `ArrayBuffer.prototype.resize`
+// has not been implemented. The following assertion prevents this test from
+// passing in runtimes which have not implemented the method.
+assert.sameValue(typeof ArrayBuffer.prototype.resize, "function");
+
+testWithTypedArrayConstructors(function(TA) {
+  var BPE = TA.BYTES_PER_ELEMENT;
+  var ab = new ArrayBuffer(BPE * 4, {maxByteLength: BPE * 5});
+  var array = new TA(ab, BPE);
+  var expected = BPE * 3;
+
+  assert.sameValue(array.byteLength, expected);
+
+  try {
+    ab.resize(BPE * 5);
+    expected = BPE * 4;
+  } catch (_) {}
+
+  assert.sameValue(array.byteLength, expected, "following grow");
+
+  try {
+    ab.resize(BPE * 3);
+    expected = BPE * 2;
+  } catch (_) {}
+
+  assert.sameValue(array.byteLength, expected, "following shrink (within bounds)");
+
+  try {
+    ab.resize(BPE);
+    expected = 0;
+  } catch (_) {}
+
+  assert.sameValue(array.byteLength, expected, "following shrink (out of bounds)");
+});

test/built-ins/TypedArray/prototype/byteLength/resizable-array-buffer-fixed.js

@@ -0,0 +1,46 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-get-%typedarray%.prototype.bytelength
+description: |
+  reset to 0 if the underlying ArrayBuffer is resized beyond the boundary of
+  the fixed-sized TypedArray instance
+includes: [testTypedArray.js]
+features: [TypedArray, resizable-arraybuffer]
+---*/
+
+// If the host chooses to throw as allowed by the specification, the observed
+// behavior will be identical to the case where `ArrayBuffer.prototype.resize`
+// has not been implemented. The following assertion prevents this test from
+// passing in runtimes which have not implemented the method.
+assert.sameValue(typeof ArrayBuffer.prototype.resize, "function");
+
+testWithTypedArrayConstructors(function(TA) {
+  var BPE = TA.BYTES_PER_ELEMENT;
+  var ab = new ArrayBuffer(BPE * 4, {maxByteLength: BPE * 5});
+  var array = new TA(ab, BPE, 2);
+
+  assert.sameValue(array.byteLength, BPE * 2);
+
+  try {
+    ab.resize(BPE * 5);
+  } catch (_) {}
+
+  assert.sameValue(array.byteLength, BPE * 2, "following grow");
+
+  try {
+    ab.resize(BPE * 3);
+  } catch (_) {}
+
+  assert.sameValue(array.byteLength, BPE * 2, "following shrink (within bounds)");
+
+  var expected;
+  try {
+    ab.resize(BPE * 2);
+    expected = 0;
+  } catch (_) {
+    expected = BPE * 2;
+  }
+
+  assert.sameValue(array.byteLength, expected, "following shrink (out of bounds)");
+});

test/built-ins/TypedArray/prototype/byteOffset/resizable-array-buffer-auto.js

@@ -0,0 +1,46 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-get-%typedarray%.prototype.byteoffset
+description: |
+  reset to 0 if the underlying ArrayBuffer is resized beyond the boundary of
+  the dynamically-sized TypedArray instance
+includes: [testTypedArray.js]
+features: [TypedArray, resizable-arraybuffer]
+---*/
+
+// If the host chooses to throw as allowed by the specification, the observed
+// behavior will be identical to the case where `ArrayBuffer.prototype.resize`
+// has not been implemented. The following assertion prevents this test from
+// passing in runtimes which have not implemented the method.
+assert.sameValue(typeof ArrayBuffer.prototype.resize, "function");
+
+testWithTypedArrayConstructors(function(TA) {
+  var BPE = TA.BYTES_PER_ELEMENT;
+  var ab = new ArrayBuffer(BPE * 4, {maxByteLength: BPE * 5});
+  var array = new TA(ab, BPE);
+
+  assert.sameValue(array.byteOffset, BPE);
+
+  try {
+    ab.resize(BPE * 5);
+  } catch (_) {}
+
+  assert.sameValue(array.byteOffset, BPE, "following grow");
+
+  try {
+    ab.resize(BPE * 3);
+  } catch (_) {}
+
+  assert.sameValue(array.byteOffset, BPE, "following shrink (within bounds)");
+
+  var expected;
+  try {
+    ab.resize(BPE);
+    expected = 0;
+  } catch (_) {
+    expected = BPE;
+  }
+
+  assert.sameValue(array.byteOffset, expected, "following shrink (out of bounds)");
+});

test/built-ins/TypedArray/prototype/byteOffset/resizable-array-buffer-fixed.js

@@ -0,0 +1,46 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-get-%typedarray%.prototype.byteoffset
+description: |
+  reset to 0 if the underlying ArrayBuffer is resized beyond the boundary of
+  the fixed-sized TypedArray instance
+includes: [testTypedArray.js]
+features: [TypedArray, resizable-arraybuffer]
+---*/
+
+// If the host chooses to throw as allowed by the specification, the observed
+// behavior will be identical to the case where `ArrayBuffer.prototype.resize`
+// has not been implemented. The following assertion prevents this test from
+// passing in runtimes which have not implemented the method.
+assert.sameValue(typeof ArrayBuffer.prototype.resize, "function");
+
+testWithTypedArrayConstructors(function(TA) {
+  var BPE = TA.BYTES_PER_ELEMENT;
+  var ab = new ArrayBuffer(BPE * 4, {maxByteLength: BPE * 5});
+  var array = new TA(ab, BPE, 2);
+
+  assert.sameValue(array.byteOffset, BPE);
+
+  try {
+    ab.resize(BPE * 5);
+  } catch (_) {}
+
+  assert.sameValue(array.byteOffset, BPE, "following grow");
+
+  try {
+    ab.resize(BPE * 3);
+  } catch (_) {}
+
+  assert.sameValue(array.byteOffset, BPE, "following shrink (within bounds)");
+
+  var expected;
+  try {
+    ab.resize(BPE * 2);
+    expected = 0;
+  } catch (_) {
+    expected = BPE;
+  }
+
+  assert.sameValue(array.byteOffset, expected, "following shrink (out of bounds)");
+});

test/built-ins/TypedArray/prototype/length/resizable-array-buffer-auto.js

@@ -0,0 +1,46 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-get-%typedarray%.prototype.length
+description: |
+  reset to 0 if the underlying ArrayBuffer is resized beyond the boundary of
+  the dynamically-sized TypedArray instance
+includes: [testTypedArray.js]
+features: [TypedArray, resizable-arraybuffer]
+---*/
+
+// If the host chooses to throw as allowed by the specification, the observed
+// behavior will be identical to the case where `ArrayBuffer.prototype.resize`
+// has not been implemented. The following assertion prevents this test from
+// passing in runtimes which have not implemented the method.
+assert.sameValue(typeof ArrayBuffer.prototype.resize, "function");
+
+testWithTypedArrayConstructors(function(TA) {
+  var BPE = TA.BYTES_PER_ELEMENT;
+  var ab = new ArrayBuffer(BPE * 4, {maxByteLength: BPE * 5});
+  var array = new TA(ab, BPE);
+  var expected = 3;
+
+  assert.sameValue(array.length, expected, "initial value");
+
+  try {
+    ab.resize(BPE * 5);
+    expected = 4;
+  } catch (_) {}
+
+  assert.sameValue(array.length, expected, "following grow");
+
+  try {
+    ab.resize(BPE * 3);
+    expected = 2;
+  } catch (_) {}
+
+  assert.sameValue(array.length, expected, "following shrink (within bounds)");
+
+  try {
+    ab.resize(BPE);
+    expected = 0;
+  } catch (_) {}
+
+  assert.sameValue(array.length, expected, "following shrink (out of bounds)");
+});

test/built-ins/TypedArray/prototype/length/resizable-array-buffer-fixed.js

@@ -0,0 +1,46 @@
+// Copyright (C) 2021 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-get-%typedarray%.prototype.length
+description: |
+  reset to 0 if the underlying ArrayBuffer is resized beyond the boundary of
+  the fixed-sized TypedArray instance
+includes: [testTypedArray.js]
+features: [TypedArray, resizable-arraybuffer]
+---*/
+
+// If the host chooses to throw as allowed by the specification, the observed
+// behavior will be identical to the case where `ArrayBuffer.prototype.resize`
+// has not been implemented. The following assertion prevents this test from
+// passing in runtimes which have not implemented the method.
+assert.sameValue(typeof ArrayBuffer.prototype.resize, "function");
+
+testWithTypedArrayConstructors(function(TA) {
+  var BPE = TA.BYTES_PER_ELEMENT;
+  var ab = new ArrayBuffer(BPE * 4, {maxByteLength: BPE * 5});
+  var array = new TA(ab, BPE, 2);
+
+  assert.sameValue(array.length, 2, "initial value");
+
+  try {
+    ab.resize(BPE * 5);
+  } catch (_) {}
+
+  assert.sameValue(array.length, 2, "following grow");
+
+  try {
+    ab.resize(BPE * 3);
+  } catch (_) {}
+
+  assert.sameValue(array.length, 2, "following shrink (within bounds)");
+
+  var expected;
+  try {
+    ab.resize(BPE * 2);
+    expected = 0;
+  } catch (_) {
+    expected = 2;
+  }
+
+  assert.sameValue(array.length, expected, "following shrink (out of bounds)");
+});