From 6788cd6f3da47f4fa05ea80b26ecb2bf3ac20f67 Mon Sep 17 00:00:00 2001
From: Scott Kyle <scott@appden.com>
Date: Mon, 12 Oct 2015 15:25:23 -0700
Subject: [PATCH] Out of bounds list item getters return undefined

Resolves #50
---
 src/RJSArray.cpp    |  4 ++++
 tests/ArrayTests.js | 18 +++++++++++-------
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/src/RJSArray.cpp b/src/RJSArray.cpp
index 3196c26e..ca24a36a 100644
--- a/src/RJSArray.cpp
+++ b/src/RJSArray.cpp
@@ -87,6 +87,10 @@ JSValueRef ArrayGetProperty(JSContextRef ctx, JSObjectRef object, JSStringRef pr
 
         return RJSObjectCreate(ctx, Object(array->realm, array->object_schema, array->get(RJSVerifiedPositiveIndex(indexStr))));
     }
+    catch (std::out_of_range &exp) {
+        // getters for nonexistent properties in JS should always return undefined
+        return JSValueMakeUndefined(ctx);
+    }
     catch (std::invalid_argument &exp) {
         // for stol failure this could be another property that is handled externally, so ignore
         return NULL;
diff --git a/tests/ArrayTests.js b/tests/ArrayTests.js
index 7a4c4f7f..85a93df5 100644
--- a/tests/ArrayTests.js
+++ b/tests/ArrayTests.js
@@ -30,6 +30,10 @@ var ArrayTests = {
 
             obj.arrayCol = [[1], [2]];
             TestCase.assertEqual(obj.arrayCol.length, 2);
+
+            TestCase.assertThrows(function() {
+                obj.arrayCol.length = 0;
+            }, 'cannot set length property on lists');
         });
     },
 
@@ -44,8 +48,8 @@ var ArrayTests = {
 
         TestCase.assertEqual(array[0].doubleCol, 3);
         TestCase.assertEqual(array[1].doubleCol, 4);
-        TestCase.assertThrows(function() { array[2]; }, 'Invalid index');
-        TestCase.assertThrows(function() { array[-1]; }, 'Invalid index');
+        TestCase.assertEqual(array[2], undefined);
+        TestCase.assertEqual(array[-1], undefined);
     },
 
     testArraySubscriptSetters: function() {
@@ -62,13 +66,13 @@ var ArrayTests = {
             TestCase.assertEqual(array[0].doubleCol, 5);
             TestCase.assertEqual(array[1].doubleCol, 6);
 
-            TestCase.assertThrows(function() {
-                array.length = 0;
-            }, 'cannot set length property on lists');
-
             TestCase.assertThrows(function() {
                 array[2] = [1];
             }, 'cannot set list item beyond its bounds');
+
+            TestCase.assertThrows(function() {
+                array[-1] = [1];
+            }, 'cannot set list item with negative index');
         });
 
         TestCase.assertThrows(function() {
@@ -133,7 +137,7 @@ var ArrayTests = {
             TestCase.assertThrows(function() {
                 array.push();
             });
-        });   
+        });
 
         TestCase.assertEqual(array.length, 4);
         TestCase.assertThrows(function() {