1 files changed, 40 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/Set/NaN-as-key.js b/js/src/jit-test/tests/Set/NaN-as-key.js
new file mode 100644
index 0000000000..1a24010a83
--- /dev/null
+++ b/js/src/jit-test/tests/Set/NaN-as-key.js
@@ -0,0 +1,40 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+// All NaNs must be treated as identical keys for Set.
+
+// Avoid constant-folding that would happen were |undefined| to be used.
+var key = -/a/g.missingProperty;
+
+var s = new Set();
+s.add(key, 17);
+assertEq(s.has(key), true);
+assertEq(s.has(-key), true);
+assertEq(s.has(NaN), true);
+
+s.delete(-key);
+assertEq(s.has(key), false);
+assertEq(s.has(-key), false);
+assertEq(s.has(NaN), false);
+
+s.add(-key, 17);
+assertEq(s.has(key), true);
+assertEq(s.has(-key), true);
+assertEq(s.has(NaN), true);
+
+s.delete(NaN);
+assertEq(s.has(key), false);
+assertEq(s.has(-key), false);
+assertEq(s.has(NaN), false);
+
+s.add(NaN, 17);
+assertEq(s.has(key), true);
+assertEq(s.has(-key), true);
+assertEq(s.has(NaN), true);
+
+s.delete(key);
+assertEq(s.has(key), false);
+assertEq(s.has(-key), false);
+assertEq(s.has(NaN), false);