1 files changed, 64 insertions, 0 deletions
diff --git a/js/src/tests/non262/Array/shift-no-has-trap.js b/js/src/tests/non262/Array/shift-no-has-trap.js
new file mode 100644
index 0000000000..e941ba7205
--- /dev/null
+++ b/js/src/tests/non262/Array/shift-no-has-trap.js
@@ -0,0 +1,64 @@
+// Test that Array.prototype.shift doesn't call the [[HasProperty]] internal
+// method of objects when retrieving the element at index 0.
+
+var log = [];
+var array = [];
+var proxy = new Proxy(array, new Proxy({}, {
+    get(t, trap, r) {
+      return (t, pk, ...more) => {
+        log.push(`${trap}:${String(pk)}`);
+        return Reflect[trap](t, pk, ...more);
+      };
+    }
+}));
+
+var result;
+
+result = Array.prototype.shift.call(proxy);
+assertEqArray(log, [
+  "get:length",
+  "set:length", "getOwnPropertyDescriptor:length", "defineProperty:length"
+]);
+assertEq(result, undefined);
+
+log.length = 0;
+array.push(1);
+
+result = Array.prototype.shift.call(proxy);
+assertEqArray(log, [
+  "get:length",
+  "get:0",
+  "deleteProperty:0",
+  "set:length", "getOwnPropertyDescriptor:length", "defineProperty:length"
+]);
+assertEq(result, 1);
+
+log.length = 0;
+array.push(2, 3);
+
+result = Array.prototype.shift.call(proxy);
+assertEqArray(log, [
+  "get:length",
+  "get:0",
+  "has:1", "get:1", "set:0", "getOwnPropertyDescriptor:0", "defineProperty:0",
+  "deleteProperty:1",
+  "set:length", "getOwnPropertyDescriptor:length", "defineProperty:length"
+]);
+assertEq(result, 2);
+
+log.length = 0;
+array.push(4, 5);
+
+result = Array.prototype.shift.call(proxy);
+assertEqArray(log, [
+  "get:length",
+  "get:0",
+  "has:1", "get:1", "set:0", "getOwnPropertyDescriptor:0", "defineProperty:0",
+  "has:2", "get:2", "set:1", "getOwnPropertyDescriptor:1", "defineProperty:1",
+  "deleteProperty:2",
+  "set:length", "getOwnPropertyDescriptor:length", "defineProperty:length"
+]);
+assertEq(result, 3);
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);