[Fix] ES2024+: GetViewByteLength, TypedArrayByteLength, `TypedA…

…rrayLength`: properly handle resizable arrays
es-shims · Jan 21, 2025 · bfe049d · bfe049d
1 parent b39976e
commit bfe049d
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Showing 4 changed files with 59 additions and 8 deletions.
diff --git a/2024/GetViewByteLength.js b/2024/GetViewByteLength.js
@@ -24,12 +24,14 @@ module.exports = function GetViewByteLength(viewRecord) {
 
 	var view = viewRecord['[[Object]]']; // step 2
 
-	var viewByteLength = dataViewByteLength(view); // view.[[ByteLength]]
+	var isFixed = IsFixedLengthArrayBuffer(dataViewBuffer(view));
+
+	var viewByteLength = isFixed ? dataViewByteLength(view) : 'AUTO'; // view.[[ByteLength]]
 	if (viewByteLength !== 'AUTO') {
 		return viewByteLength; // step 3
 	}
 
-	if (IsFixedLengthArrayBuffer(dataViewBuffer(view))) {
+	if (isFixed) {
 		throw new $TypeError('Assertion failed: DataView’s ArrayBuffer is not fixed length'); // step 4
 	}
 

diff --git a/2024/TypedArrayByteLength.js b/2024/TypedArrayByteLength.js
@@ -2,12 +2,14 @@
 
 var $TypeError = require('es-errors/type');
 
+var IsFixedLengthArrayBuffer = require('./IsFixedLengthArrayBuffer');
 var IsTypedArrayOutOfBounds = require('./IsTypedArrayOutOfBounds');
 var TypedArrayElementSize = require('./TypedArrayElementSize');
 var TypedArrayLength = require('./TypedArrayLength');
 
 var isTypedArrayWithBufferWitnessRecord = require('../helpers/records/typed-array-with-buffer-witness-record');
 
+var typedArrayByffer = require('typed-array-buffer');
 var typedArrayByteLength = require('typed-array-byte-length');
 
 // https://262.ecma-international.org/15.0/#sec-typedarraybytelength
@@ -28,7 +30,9 @@ module.exports = function TypedArrayByteLength(taRecord) {
 
 	var O = taRecord['[[Object]]']; // step 4
 
-	var byteLength = typedArrayByteLength(O);
+	var isFixed = IsFixedLengthArrayBuffer(typedArrayByffer(O));
+
+	var byteLength = isFixed ? typedArrayByteLength(O) : 'AUTO';
 	if (byteLength !== 'AUTO') {
 		return byteLength; // step 5
 	}

diff --git a/2024/TypedArrayLength.js b/2024/TypedArrayLength.js
@@ -13,7 +13,7 @@ var typedArrayBuffer = require('typed-array-buffer');
 var typedArrayByteOffset = require('typed-array-byte-offset');
 var typedArrayLength = require('typed-array-length');
 
-// http://www.ecma-international.org/ecma-262/15.0/#sec-typedarraylength
+// https://www.ecma-international.org/ecma-262/15.0/#sec-typedarraylength
 
 module.exports = function TypedArrayLength(taRecord) {
 	if (!isTypedArrayWithBufferWitnessRecord(taRecord)) {
@@ -26,12 +26,14 @@ module.exports = function TypedArrayLength(taRecord) {
 
 	var O = taRecord['[[Object]]']; // step 2
 
-	var length = typedArrayLength(O);
+	var isFixed = IsFixedLengthArrayBuffer(typedArrayBuffer(O));
+
+	var length = isFixed ? typedArrayLength(O) : 'AUTO';
 	if (length !== 'AUTO') {
 		return length; // step 3
 	}
 
-	if (IsFixedLengthArrayBuffer(typedArrayBuffer(O))) {
+	if (isFixed) {
 		throw new $TypeError('Assertion failed: array buffer is not fixed length'); // step 4
 	}
 

diff --git a/test/tests.js b/test/tests.js
@@ -18007,9 +18007,52 @@ var es2024 = function ES2024(ES, ops, expectedMissing, skips) {
 
 					// TODO: actual TA byteLength auto, but not fixed length? (may not be possible)
 
-					tat.test('non-fixed length, return floor((byteLength - byteOffset) / elementSize)', { todo: 'blocked on native resizable ABs/growable SABs' });
+					var elementSize = elementSizes['$' + type];
+
+					tat.test(
+						'non-fixed length, return floor((byteLength - byteOffset) / elementSize)',
+						{ skip: !('resizable' in ArrayBuffer.prototype) },
+						function (tsat) {
+							var rab = new ArrayBuffer(17, { maxByteLength: 64 });
+							var arr = new TA(rab, 8);
+							record = ES.MakeTypedArrayWithBufferWitnessRecord(arr, 'UNORDERED');
+
+							tsat.equal(
+								ES.TypedArrayLength(record),
+								Math.floor((17 - 8) / elementSize),
+								type + ' + resizable AB: has expected length'
+							);
+
+							tsat.end();
+						}
+					);
+
+					tat.test(
+						'non-fixed length, detached throws',
+						{ skip: !('resizable' in ArrayBuffer.prototype) || !canDetach },
+						function (tsat) {
+							var rab = new ArrayBuffer(17, { maxByteLength: 64 });
+							var arr = new TA(rab, 8);
+							record = ES.MakeTypedArrayWithBufferWitnessRecord(arr, 'UNORDERED');
+
+							ES.DetachArrayBuffer(rab);
 
-					tat.test('non-fixed length, detached throws', { todo: 'blocked on native resizable ABs/growable SABs' });
+							tsat['throws'](
+								function () { ES.TypedArrayLength(record); },
+								TypeError,
+								'detached RAB with a non-detached TAWBR throws'
+							);
+
+							record = ES.MakeTypedArrayWithBufferWitnessRecord(arr, 'UNORDERED');
+							tsat['throws'](
+								function () { ES.TypedArrayLength(record); },
+								TypeError,
+								'detached RAB with a detached TAWBR throws'
+							);
+
+							tsat.end();
+						}
+					);
 				});
 			});