1 files changed, 30 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/String/prototype/toWellFormed/to-string.js b/js/src/tests/test262/built-ins/String/prototype/toWellFormed/to-string.js
new file mode 100644
index 0000000000..200f9ccd16
--- /dev/null
+++ b/js/src/tests/test262/built-ins/String/prototype/toWellFormed/to-string.js
@@ -0,0 +1,30 @@
+// |reftest| shell-option(--enable-well-formed-unicode-strings) skip-if(!String.prototype.toWellFormed||!xulRuntime.shell) -- String.prototype.toWellFormed is not enabled unconditionally, requires shell-options
+// Copyright (C) 2022 Jordan Harband. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-string.prototype.towellformed
+description: >
+  The method should coerce the receiver to a string.
+info: |
+  String.prototype.toWellFormed ( )
+
+  1. Let O be ? RequireObjectCoercible(this value).
+  2. Let S be ? ToString(O).
+  …
+
+features: [String.prototype.toWellFormed]
+---*/
+
+var obj = {
+    toString: function () {
+        throw new Test262Error('calls ToString');
+    }
+};
+
+assert.throws(
+    Test262Error,
+    function () { String.prototype.toWellFormed.call(obj); },
+    'coerces the receiver to a string'
+);
+
+reportCompare(0, 0);