1 files changed, 54 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/ion/object-keys-02.js b/js/src/jit-test/tests/ion/object-keys-02.js
new file mode 100644
index 0000000000..077433431b
--- /dev/null
+++ b/js/src/jit-test/tests/ion/object-keys-02.js
@@ -0,0 +1,54 @@
+
+// This test case check some code frequently used in the wild, with some object
+// (proxy) for which the optimization we have deployed do not work, as the
+// assumption the Object.keys(...) can be elided without having noticeable
+// side-effects.
+
+// Similar functions are part of popular framework such as React and Angular.
+function shallowEqual(o1, o2) {
+    var k1 = Object.keys(o1);
+    var k2 = Object.keys(o2);
+    if (k1.length != k2.length) {
+        return false;
+    }
+    for (var k = 0; k < k1.length; k++) {
+        if (!Object.hasOwnProperty.call(o2, k1[k]) || !Object.is(o1[k1[k]], o2[k1[k]])) {
+            return false;
+        }
+    }
+    return true;
+}
+
+let sideEffectCounter = 0;
+const payload = {x: 5, a: 1, b: 2, c: 3, d: 4};
+const handler = {
+    ownKeys(target) {
+        // side-effect that should not be removed.
+        sideEffectCounter++;
+        // answer returned.
+        return Reflect.ownKeys(target);
+    },
+};
+const proxy = new Proxy(payload, handler);
+
+let objs = [
+    {x:0, a: 1, b: 2},
+    {x:1, b: 1, c: 2},
+    {x:2, c: 1, d: 2},
+    {x:3, a: 1, b: 2, c: 3},
+    {x:4, b: 1, c: 2, d: 3},
+    proxy
+];
+
+with({}) {}
+let iterMax = 1000;
+for (let i = 0; i < iterMax; i++) {
+    for (let o1 of objs) {
+        for (let o2 of objs) {
+            assertEq(shallowEqual(o1, o2), Object.is(o1, o2));
+        }
+    }
+}
+
+let expectedSideEffects = 2 * objs.length * iterMax;
+assertEq(sideEffectCounter, expectedSideEffects);