Improvements to Ref for Namespaced Scopes (#83)

* Exposed more info from Ref

* Fix linting error

* Added line to test Namespace method

schema/ref.go

@@ -7,13 +7,15 @@ import (
 
 // Ref holds the definition of a reference to a scope-wide object. The ref must always be inside a scope,
 // either directly or indirectly. If several scopes are embedded within each other, the Ref references the object
-// in the current scope.
+// in the scope specified. DEFAULT_NAMESPACE for current scope.
 type Ref interface {
 	Object
 
 	ID() string
+	Namespace() string
 	Display() Display
 	GetObject() Object
+	ObjectReady() bool
 }
 
 // NewRefSchema creates a new reference to an object in a wrapping Scope by ID.
@@ -87,10 +89,18 @@ func (r *RefSchema) ReflectedType() reflect.Type {
 	return r.referencedObjectCache.ReflectedType()
 }
 
+func (r *RefSchema) ObjectReady() bool {
+	return r.referencedObjectCache != nil
+}
+
 func (r *RefSchema) ID() string {
 	return r.IDValue
 }
 
+func (r *RefSchema) Namespace() string {
+	return r.ObjectNamespace
+}
+
 func (r *RefSchema) Display() Display {
 	return r.DisplayValue
 }
@@ -104,8 +114,12 @@ func (r *RefSchema) ApplyScope(scope Scope, namespace string) {
 	objects := scope.Objects()
 	referencedObject, ok := objects[r.IDValue]
 	if !ok {
+		availableObjects := ""
+		for objectID := range objects {
+			availableObjects += objectID + "\n"
+		}
 		panic(BadArgumentError{
-			Message: fmt.Sprintf("Referenced object '%s' not found in scope with namespace %q", r.IDValue, namespace),
+			Message: fmt.Sprintf("Referenced object '%s' not found in scope with namespace %q; available:\n%s", r.IDValue, namespace, availableObjects),
 		})
 	}
 	r.referencedObjectCache = referencedObject

schema/scope_test.go

@@ -321,7 +321,7 @@ func TestApplyingExternalNamespace(t *testing.T) {
 	// The applied scope must be passed down to all of those types, validating
 	// that the scope gets applied down and that errors are propagated up.
 	refRefSchema := schema.NewNamespacedRefSchema("scopeTestObjectB", "test-namespace", nil)
-
+	assert.Equals(t, refRefSchema.Namespace(), "test-namespace")
 	refProperty := schema.NewPropertySchema(
 		refRefSchema,
 		nil,
@@ -463,7 +463,9 @@ func TestApplyingExternalNamespace(t *testing.T) {
 			err = testData.ref.ValidateReferences()
 			assert.Error(t, err)
 			assert.Contains(t, err.Error(), "missing its link")
+			assert.Equals(t, testData.ref.ObjectReady(), false)
 			testData.scope.ApplyScope(externalScope, "test-namespace")
+			assert.Equals(t, testData.ref.ObjectReady(), true)
 			// Now it's applied, so the error should be resolved.
 			// Outermost
 			assert.NoError(t, testData.scope.ValidateReferences())