Assert that hole elements are empty after fillHoles.

Author: woess

graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/runtime/array/dyn/AbstractJSObjectArray.java

@@ -141,6 +141,7 @@ protected final void fillHoles(JSDynamicObject object, int internalIndex, int gr
         if (grown != 0) {
             incrementHolesCount(object, Math.abs(grown) - 1);
         }
+        assert checkFillHoles(object, internalIndex, grown);
     }
 
     @Override

graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/runtime/array/dyn/AbstractObjectArray.java

@@ -143,6 +143,7 @@ protected final void fillHoles(JSDynamicObject object, int internalIndex, int gr
         if (grown != 0) {
             incrementHolesCount(object, Math.abs(grown) - 1);
         }
+        assert checkFillHoles(object, internalIndex, grown);
     }
 
     @Override

graal-js/src/com.oracle.truffle.js/src/com/oracle/truffle/js/runtime/array/dyn/AbstractWritableArray.java

@@ -354,6 +354,27 @@ protected void fillHoles(JSDynamicObject object, int internalIndex, int grown, N
         }
     }
 
+    protected final boolean checkFillHoles(JSDynamicObject object, int internalIndex, int grown) {
+        int start;
+        int end;
+        if (grown > 1) {
+            start = internalIndex - grown + 1;
+            end = internalIndex;
+        } else if (grown < -1) {
+            start = internalIndex + 1;
+            end = internalIndex - grown;
+        } else {
+            return true;
+        }
+
+        for (int i = start; i < end; i++) {
+            if (!isHolePrepared(object, i)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
     public abstract AbstractWritableArray toDouble(JSDynamicObject object, long index, double value);
 
     public abstract AbstractWritableArray toObject(JSDynamicObject object, long index, Object value);