1 files changed, 20 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/basic/negative-zero-index.js b/js/src/jit-test/tests/basic/negative-zero-index.js
new file mode 100644
index 0000000000..7f585a115e
--- /dev/null
+++ b/js/src/jit-test/tests/basic/negative-zero-index.js
@@ -0,0 +1,20 @@
+function test() {
+    const array = [1];
+    for (let i = 0; i < 10; i++) {
+        assertEq(array[0], 1);
+        assertEq(array[0.0], 1);
+        assertEq(array[-0.0], 1);
+        // ToPropertyKey(-0.0) is "0", but "-0" is distinct!
+        assertEq(array["-0"], undefined);
+    }
+
+    const string = "a";
+    for (let i = 0; i < 10; i++) {
+        assertEq(string[0], "a");
+        assertEq(string[0.0], "a");
+        assertEq(string[-0.0], "a");
+        assertEq(string["-0"], undefined);
+    }
+}
+
+test();