1 files changed, 25 insertions, 0 deletions
diff --git a/js/src/tests/test262/prs/3994/built-ins/Uint8Array/fromBase64/alphabet.js b/js/src/tests/test262/prs/3994/built-ins/Uint8Array/fromBase64/alphabet.js
new file mode 100644
index 0000000000..c893bf952a
--- /dev/null
+++ b/js/src/tests/test262/prs/3994/built-ins/Uint8Array/fromBase64/alphabet.js
@@ -0,0 +1,25 @@
+// |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.frombase64
+description: Conversion of base64 strings to Uint8Arrays exercising the alphabet option
+includes: [compareArray.js]
+features: [uint8array-base64, TypedArray]
+---*/
+
+assert.compareArray(Uint8Array.fromBase64('x+/y'), [199, 239, 242]);
+assert.compareArray(Uint8Array.fromBase64('x+/y', { alphabet: 'base64' }), [199, 239, 242]);
+assert.throws(SyntaxError, function() {
+  Uint8Array.fromBase64('x+/y', { alphabet: 'base64url' });
+});
+
+assert.compareArray(Uint8Array.fromBase64('x-_y', { alphabet: 'base64url' }), [199, 239, 242]);
+assert.throws(SyntaxError, function() {
+  Uint8Array.fromBase64('x-_y');
+});
+assert.throws(SyntaxError, function() {
+  Uint8Array.fromBase64('x-_y', { alphabet: 'base64' });
+});
+
+reportCompare(0, 0);