1 files changed, 42 insertions, 0 deletions
diff --git a/js/src/tests/test262/prs/3994/built-ins/Uint8Array/prototype/toBase64/detached-buffer.js b/js/src/tests/test262/prs/3994/built-ins/Uint8Array/prototype/toBase64/detached-buffer.js
new file mode 100644
index 0000000000..0904454743
--- /dev/null
+++ b/js/src/tests/test262/prs/3994/built-ins/Uint8Array/prototype/toBase64/detached-buffer.js
@@ -0,0 +1,42 @@
+// |reftest| shell-option(--enable-uint8array-base64) skip-if(!Uint8Array.fromBase64||!xulRuntime.shell) -- uint8array-base64 is not enabled unconditionally, requires shell-options
+// Copyright (C) 2024 Kevin Gibbons. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-uint8array.prototype.tobase64
+description: Uint8Array.prototype.toBase64 checks for detachedness after side-effects are finished
+includes: [detachArrayBuffer.js]
+features: [uint8array-base64, TypedArray]
+---*/
+
+var array = new Uint8Array(2);
+var getterCalls = 0;
+var receiverDetachingOptions = {};
+Object.defineProperty(receiverDetachingOptions, "alphabet", {
+  get: function() {
+    getterCalls += 1;
+    $DETACHBUFFER(array.buffer);
+    return "base64";
+  }
+});
+assert.throws(TypeError, function() {
+  array.toBase64(receiverDetachingOptions);
+});
+assert.sameValue(getterCalls, 1);
+
+
+var detached = new Uint8Array(2);
+$DETACHBUFFER(detached.buffer);
+var getterCalls = 0;
+var sideEffectingOptions = {};
+Object.defineProperty(sideEffectingOptions, "alphabet", {
+  get: function() {
+    getterCalls += 1;
+    return "base64";
+  }
+});
+assert.throws(TypeError, function() {
+  detached.toBase64(sideEffectingOptions);
+});
+assert.sameValue(getterCalls, 1);
+
+reportCompare(0, 0);