[Edit] Add test case for double-wrapping

Add test case to detect double-wrapping of domain objects
retrieved via the editable domain object cache, identified
as the root cause of WTD-1071.

platform/commonUI/edit/test/objects/EditableDomainObjectCacheSpec.js

@@ -21,6 +21,9 @@ define(
                     getModel: function () { return {}; },
                     getCapability: function (name) {
                         return completionCapability;
+                    },
+                    hasCapability: function (name) {
+                        return false;
                     }
                 };
             }
@@ -29,6 +32,9 @@ define(
                 var result = Object.create(domainObject);
                 result.wrapped = true;
                 result.wrappedModel = model;
+                result.hasCapability = function (name) {
+                    return name === 'editor';
+                };
                 captured.wraps = (captured.wraps || 0) + 1;
                 return result;
             }
@@ -112,6 +118,19 @@ define(
                 expect(cache.isRoot(domainObjects[2])).toBeFalsy();
             });
 
+            it("does not double-wrap objects", function () {
+                var domainObject = new TestObject('test-id'),
+                    wrappedObject = cache.getEditableObject(domainObject);
+
+                // Same instance should be returned if you try to wrap
+                // twice. This is necessary, since it's possible to (e.g.)
+                // use a context capability on an object retrieved via
+                // composition, in which case a result will already be
+                // wrapped.
+                expect(cache.getEditableObject(wrappedObject))
+                    .toBe(wrappedObject);
+            });
+
 
         });
     }