1 files changed, 36 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/Object/prototype/toString/symbol-tag-set-builtin.js b/js/src/tests/test262/built-ins/Object/prototype/toString/symbol-tag-set-builtin.js
new file mode 100644
index 0000000000..5591b1ee17
--- /dev/null
+++ b/js/src/tests/test262/built-ins/Object/prototype/toString/symbol-tag-set-builtin.js
@@ -0,0 +1,36 @@
+// |reftest| shell-option(--enable-iterator-helpers) skip-if(!this.hasOwnProperty('Iterator')||!xulRuntime.shell) -- iterator-helpers is not enabled unconditionally, requires shell-options
+// Copyright (C) 2019 Alexey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-object.prototype.tostring
+description: >
+  Non-string values of `Symbol.toStringTag` property are ignored.
+info: |
+  Object.prototype.toString ( )
+
+  [...]
+  15. Let tag be ? Get(O, @@toStringTag).
+  16. If Type(tag) is not String, set tag to builtinTag.
+  17. Return the string-concatenation of "[object ", tag, and "]".
+features: [Symbol.toStringTag, Symbol.iterator, Set, iterator-helpers]
+---*/
+
+var toString = Object.prototype.toString;
+
+var set = new Set();
+delete Set.prototype[Symbol.toStringTag];
+assert.sameValue(toString.call(set), '[object Object]');
+
+var setIter = set[Symbol.iterator]();
+var setIterProto = Object.getPrototypeOf(setIter);
+assert.sameValue(toString.call(setIter), '[object Set Iterator]');
+Object.defineProperty(setIterProto, Symbol.toStringTag, {
+  configurable: true,
+  get: function() { return new String('ShouldNotBeUnwrapped'); },
+});
+assert.sameValue(toString.call(setIter), '[object Object]');
+
+delete setIterProto[Symbol.toStringTag];
+assert.sameValue(toString.call(setIter), '[object Iterator]');
+
+reportCompare(0, 0);