1 files changed, 22 insertions, 0 deletions
diff --git a/js/src/tests/test262/annexB/built-ins/unescape/to-primitive-observe.js b/js/src/tests/test262/annexB/built-ins/unescape/to-primitive-observe.js
new file mode 100644
index 0000000000..3c6c2068e1
--- /dev/null
+++ b/js/src/tests/test262/annexB/built-ins/unescape/to-primitive-observe.js
@@ -0,0 +1,22 @@
+// Copyright (C) 2020 Qu Xing. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-unescape-string
+description: Observable operations from string coercion
+info: |
+    B.2.1.2 unescape ( string )
+
+    1. Set string to ? ToString(string).
+    ....
+features: [Symbol.toPrimitive]
+---*/
+
+var obj = {
+  toString() { throw new Test262Error('this should be unreachable'); },
+  valueOf() { throw new Test262Error('this should be unreachable'); },
+  [Symbol.toPrimitive]() { return 'success'; }
+};
+
+assert.sameValue(unescape(obj), 'success');
+
+reportCompare(0, 0);