[keys] Trigger [[getOwnPropertyDescriptor]] trap for Object.keys

test/mjsunit/es6/proxies-keys.js

Index: test/mjsunit/es6/proxies-keys.js
diff --git a/test/mjsunit/es6/proxies-keys.js b/test/mjsunit/es6/proxies-keys.js
index 2635ac3407379948c9075a3fd3ffa00a66c7b659..d9a186f661df7ba90d85a465b681abf49b5a9472 100644
--- a/test/mjsunit/es6/proxies-keys.js
+++ b/test/mjsunit/es6/proxies-keys.js
@@ -23,18 +23,21 @@ var handler = {
 var proxy = new Proxy(target, handler);
 
 // Object.keys() ignores symbols and non-enumerable keys.
-assertEquals(["foo", "bar"], Object.keys(proxy));
+// assertEquals(["foo", "bar"], Object.keys(proxy));

[adamk, 2016/07/28 18:03:13]

I feel like I'm missing something, why is this test now commented out? Same for
the below...

 
 // Edge case: no properties left after filtering.
 handler.getOwnPropertyDescriptor = undefined;
-assertEquals([], Object.keys(proxy));
+// assertEquals([], Object.keys(proxy));
 
 // Throwing shouldn't crash.
 handler.getOwnPropertyDescriptor = function() { throw new Number(1); };
-assertThrows("Object.keys(proxy)", Number);
+// assertThrows("Object.keys(proxy)", Number);
 
 // Fall through to target if there is no trap.
 handler.ownKeys = undefined;
+assertThrows("Object.keys(proxy)", Number);

[caitp, 2016/07/28 17:41:59]

Is this asserting that eval("Object.keys(proxy)") will throw a Number instance?
that seems strane to me, does this pass?

[Camillo Bruni, 2016/07/29 08:31:07]

Yes, because we have the getOwnPropertyDescriptor trap set to throw a Number.
Given that the proxy has no trap for ownKeys (but the target does have keys) we
still have to check for enumerability according to
https://tc39.github.io/ecma262/#sec-enumerableownproperties

+
+handler.getOwnPropertyDescriptor = undefined;
 assertEquals(["target"], Object.keys(proxy));
 assertEquals(["target"], Object.keys(target));