1 files changed, 31 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/JSON/stringify/replacer-array-duplicates.js b/js/src/tests/test262/built-ins/JSON/stringify/replacer-array-duplicates.js
new file mode 100644
index 0000000000..5351d6fb56
--- /dev/null
+++ b/js/src/tests/test262/built-ins/JSON/stringify/replacer-array-duplicates.js
@@ -0,0 +1,31 @@
+// Copyright (C) 2019 Aleksey Shvayka. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-json.stringify
+description: >
+  Replacer array is deduped before Get.
+info: |
+  JSON.stringify ( value [ , replacer [ , space ] ] )
+
+  [...]
+  4. If Type(replacer) is Object, then
+    [...]
+    4. Repeat, while k < len,
+      a. Let v be ? Get(replacer, ! ToString(k)).
+      [...]
+      f. If item is not undefined and item is not currently an element of PropertyList, then
+        i. Append item to the end of PropertyList.
+---*/
+
+var getCalls = 0;
+var value = {
+  get key() {
+    getCalls += 1;
+    return true;
+  },
+};
+
+assert.sameValue(JSON.stringify(value, ['key', 'key']), '{"key":true}');
+assert.sameValue(getCalls, 1);
+
+reportCompare(0, 0);