[Core] Edit-wrap relationship capability

Wrap objects retrieved via the relationship capability
with Edit mode caching etc, for WTD-1007.

platform/commonUI/edit/test/capabilities/EditableRelationshipCapabilitySpec.js

@@ -0,0 +1,54 @@
+/*global define,describe,it,expect,beforeEach,jasmine*/
+
+define(
+    ["../../src/capabilities/EditableRelationshipCapability"],
+    function (EditableRelationshipCapability) {
+        "use strict";
+
+        describe("An editable relationship capability", function () {
+            var mockContext,
+                mockEditableObject,
+                mockDomainObject,
+                mockTestObject,
+                someValue,
+                mockFactory,
+                capability;
+
+            beforeEach(function () {
+                // EditableContextCapability should watch ALL
+                // methods for domain objects, so give it an
+                // arbitrary interface to wrap.
+                mockContext =
+                    jasmine.createSpyObj("context", [ "getDomainObject" ]);
+                mockTestObject = jasmine.createSpyObj(
+                    "domainObject",
+                    [ "getId", "getModel", "getCapability" ]
+                );
+                mockFactory =
+                    jasmine.createSpyObj("factory", ["getEditableObject"]);
+
+                someValue = { x: 42 };
+
+                mockContext.getDomainObject.andReturn(mockTestObject);
+                mockFactory.getEditableObject.andReturn(someValue);
+
+                capability = new EditableRelationshipCapability(
+                    mockContext,
+                    mockEditableObject,
+                    mockDomainObject,
+                    mockFactory
+                );
+
+            });
+
+            // Most behavior is tested for EditableLookupCapability,
+            // so just verify that this isse
+            it("presumes non-idempotence of its wrapped capability", function () {
+                expect(capability.getDomainObject())
+                    .toEqual(capability.getDomainObject());
+                expect(mockContext.getDomainObject.calls.length).toEqual(2);
+            });
+
+        });
+    }
+);