1 files changed, 36 insertions, 0 deletions
diff --git a/js/src/tests/test262/language/statements/class/elements/private-method-double-initialisation-set.js b/js/src/tests/test262/language/statements/class/elements/private-method-double-initialisation-set.js
new file mode 100644
index 0000000000..41a8f92878
--- /dev/null
+++ b/js/src/tests/test262/language/statements/class/elements/private-method-double-initialisation-set.js
@@ -0,0 +1,36 @@
+// Copyright (C) 2021 André Bargull. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: >
+  Throws TypeError when attempting to install private methods multiple times.
+esid: sec-privatemethodoraccessoradd
+info: |
+  7.3.28 PrivateMethodOrAccessorAdd ( method, O )
+    1. Assert: method.[[Kind]] is either method or accessor.
+    2. Let entry be ! PrivateElementFind(method.[[Key]], O).
+    3. If entry is not empty, throw a TypeError exception.
+    ...
+
+features: [class, class-methods-private]
+---*/
+
+class Base {
+  constructor(o) {
+    return o;
+  }
+}
+
+class C extends Base {
+  set #p(x) {}
+}
+
+var obj = {};
+
+new C(obj);
+
+assert.throws(TypeError, function() {
+  new C(obj);
+});
+
+reportCompare(0, 0);