Refactor dependsOn into References

See #233 for discussion

it/sc/service_catalog_test.go

@@ -68,8 +68,10 @@ func TestServiceCatalog(t *testing.T) {
 					},
 				},
 				{
-					Name:      smith_v1.ResourceName(binding.Name),
-					DependsOn: []smith_v1.ResourceName{smith_v1.ResourceName(instance.Name)},
+					Name: smith_v1.ResourceName(binding.Name),
+					References: []smith_v1.Reference{
+						{Resource: smith_v1.ResourceName(instance.Name)},
+					},
 					Spec: smith_v1.ResourceSpec{
 						Object: binding,
 					},

it/workflow_test.go

@@ -69,8 +69,10 @@ func TestWorkflow(t *testing.T) {
 		Spec: smith_v1.BundleSpec{
 			Resources: []smith_v1.Resource{
 				{
-					Name:      "config1res",
-					DependsOn: []smith_v1.ResourceName{"secret2res"},
+					Name: "config1res",
+					References: []smith_v1.Reference{
+						{Resource: "secret2res"},
+					},
 					Spec: smith_v1.ResourceSpec{
 						Object: c1,
 					},

pkg/apis/smith/v1/types.go

@@ -184,6 +184,9 @@ func (bs *BundleStatus) GetResourceStatus(resName ResourceName) (int, *ResourceS
 // ResourceName is a reference to another Resource in the same bundle.
 type ResourceName string
 
+// ReferenceName is a the name of a reference which can be used inside a resource.
+type ReferenceName string
+
 // PluginName is a name of a plugin to be invoked.
 type PluginName string
 
@@ -194,11 +197,27 @@ type Resource struct {
 	Name ResourceName `json:"name"`
 
 	// Explicit dependencies.
-	DependsOn []ResourceName `json:"dependsOn,omitempty"`
+	References []Reference `json:"reference,omitempty"`
 
 	Spec ResourceSpec `json:"spec"`
 }
 
+// +k8s:deepcopy-gen=true
+// Refer to a part of another object
+type Reference struct {
+	Name     ReferenceName `json:"name,omitempty"`
+	Resource ResourceName  `json:"resource"`
+	Path     string        `json:"path,omitempty"`
+	Example  interface{}   `json:"example,omitempty"`
+	Modifier string        `json:"modifier,omitempty"`
+}
+
+// DeepCopyInto is an deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *Reference) DeepCopyInto(out *Reference) {
+	*out = *in
+	out.Example = runtime.DeepCopyJSONValue(in.Example)
+}
+
 // +k8s:deepcopy-gen=true
 // ResourceSpec is a union type - either object of plugin can be specified.
 type ResourceSpec struct {

pkg/controller/BUILD.bazel

@@ -30,6 +30,7 @@ go_library(
         "//vendor/github.com/ash2k/stager/wait:go_default_library",
         "//vendor/github.com/kubernetes-incubator/service-catalog/pkg/apis/servicecatalog/v1beta1:go_default_library",
         "//vendor/github.com/pkg/errors:go_default_library",
+        "//vendor/go.uber.org/multierr:go_default_library",
         "//vendor/go.uber.org/zap:go_default_library",
         "//vendor/golang.org/x/crypto/bcrypt:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",

pkg/controller/bundle_sync_task.go

@@ -494,8 +494,8 @@ func sortBundle(bundle *smith_v1.Bundle) (*graph.Graph, []graph.V, error) {
 	}
 
 	for _, res := range bundle.Spec.Resources {
-		for _, d := range res.DependsOn {
-			if err := g.AddEdge(res.Name, d); err != nil {
+		for _, reference := range res.References {
+			if err := g.AddEdge(res.Name, reference.Resource); err != nil {
 				return nil, nil, err
 			}
 		}

pkg/controller/controller_worker_test.go

@@ -16,19 +16,31 @@ func TestBundleSort(t *testing.T) {
 		Spec: smith_v1.BundleSpec{
 			Resources: []smith_v1.Resource{
 				{
-					Name:      "a",
-					DependsOn: []smith_v1.ResourceName{"c"},
+					Name: "a",
+					References: []smith_v1.Reference{
+						{
+							Resource: "c",
+						},
+					},
 				},
 				{
 					Name: "b",
 				},
 				{
-					Name:      "c",
-					DependsOn: []smith_v1.ResourceName{"b"},
+					Name: "c",
+					References: []smith_v1.Reference{
+						{
+							Resource: "b",
+						},
+					},
 				},
 				{
-					Name:      "d",
-					DependsOn: []smith_v1.ResourceName{"e"},
+					Name: "d",
+					References: []smith_v1.Reference{
+						{
+							Resource: "e",
+						},
+					},
 				},
 				{
 					Name: "e",
@@ -48,19 +60,31 @@ func TestBundleSortMissingDependency(t *testing.T) {
 		Spec: smith_v1.BundleSpec{
 			Resources: []smith_v1.Resource{
 				{
-					Name:      "a",
-					DependsOn: []smith_v1.ResourceName{"x"},
+					Name: "a",
+					References: []smith_v1.Reference{
+						{
+							Resource: "x",
+						},
+					},
 				},
 				{
 					Name: "b",
 				},
 				{
-					Name:      "c",
-					DependsOn: []smith_v1.ResourceName{"b"},
+					Name: "c",
+					References: []smith_v1.Reference{
+						{
+							Resource: "b",
+						},
+					},
 				},
 				{
-					Name:      "d",
-					DependsOn: []smith_v1.ResourceName{"e"},
+					Name: "d",
+					References: []smith_v1.Reference{
+						{
+							Resource: "e",
+						},
+					},
 				},
 				{
 					Name: "e",
@@ -71,3 +95,45 @@ func TestBundleSortMissingDependency(t *testing.T) {
 	_, sorted, err := sortBundle(&bundle)
 	require.EqualError(t, err, "vertex \"x\" not found", "%v", sorted)
 }
+
+func TestBundleSortSelfReference(t *testing.T) {
+	t.Parallel()
+	bundle := smith_v1.Bundle{
+		Spec: smith_v1.BundleSpec{
+			Resources: []smith_v1.Resource{
+				{
+					Name: "a",
+					References: []smith_v1.Reference{
+						{
+							Resource: "a",
+						},
+					},
+				},
+				{
+					Name: "b",
+				},
+				{
+					Name: "c",
+					References: []smith_v1.Reference{
+						{
+							Resource: "b",
+						},
+					},
+				},
+				{
+					Name: "d",
+					References: []smith_v1.Reference{
+						{
+							Resource: "e",
+						},
+					},
+				},
+				{
+					Name: "e",
+				},
+			},
+		},
+	}
+	_, sorted, err := sortBundle(&bundle)
+	require.EqualError(t, err, "cycle error: [a a]", "%v", sorted)
+}