1 files changed, 18 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/collections/Map-delete.js b/js/src/jit-test/tests/collections/Map-delete.js
new file mode 100644
index 0000000000..d200eb873f
--- /dev/null
+++ b/js/src/jit-test/tests/collections/Map-delete.js
@@ -0,0 +1,18 @@
+// Map.prototype.delete works whether the key is present or not.
+
+var m = new Map;
+var key = {};
+
+// when the map is new
+assertEq(m.delete(key), false);
+assertEq(m.has(key), false);
+
+// when the key is present
+assertEq(m.set(key, 'x'), m);
+assertEq(m.delete(key), true);
+assertEq(m.has(key), false);
+assertEq(m.get(key), undefined);
+
+// when the key has already been deleted
+assertEq(m.delete(key), false);
+assertEq(m.has(key), false);