1 files changed, 47 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/parser/fold-constant-index-access.js b/js/src/jit-test/tests/parser/fold-constant-index-access.js
new file mode 100644
index 0000000000..eabe2c5787
--- /dev/null
+++ b/js/src/jit-test/tests/parser/fold-constant-index-access.js
@@ -0,0 +1,47 @@
+// Constant folding optimizes the element access with string that contains
+// 32-bit unsignned integer.
+// The result shouldn't be visible to the script, and the optimization shouldn't
+// change the behavior.
+
+// Asserts that the property name and the value are same.
+var validator = new Proxy({}, {
+  set(that, prop, value) {
+    assertEq(prop, value);
+  }
+});
+
+// Optimizable cases.
+validator["0"] = "0";
+validator["1"] = "1";
+validator["10"] = "10";
+validator["123"] = "123";
+
+// Not optimizable cases.
+
+// More than UINT32_MAX.
+validator["4294967296"] = "4294967296";
+validator["10000000000000"] = "10000000000000";
+
+// Leading 0.
+validator["01"] = "01";
+validator["0000001"] = "0000001";
+
+// Sign.
+validator["+1"] = "+1";
+validator["-1"] = "-1";
+
+// Non-decimal
+validator["0b1"] = "0b1";
+validator["0o1"] = "0o1";
+validator["0x1"] = "0x1";
+
+// Non-integer.
+validator["1.1"] = "1.1";
+validator["1."] = "1.";
+validator[".1"] = ".1";
+validator["0.1"] = "0.1";
+
+// Extra character.
+validator["1a"] = "1a";
+validator["1 "] = "1 ";
+validator[" 1"] = " 1";