terraform: orphan dependencies should be inverted

terraform/graph_builder_test.go

@@ -154,6 +154,49 @@ func TestBuiltinGraphBuilder_multiLevelModule(t *testing.T) {
 	}
 }
 
+func TestBuiltinGraphBuilder_orphanDeps(t *testing.T) {
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.foo": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.bar": &ResourceState{
+						Type:         "aws_instance",
+						Dependencies: []string{"aws_instance.foo"},
+						Primary: &InstanceState{
+							ID: "bar",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	b := &BuiltinGraphBuilder{
+		Root:     testModule(t, "graph-builder-orphan-deps"),
+		State:    state,
+		Validate: true,
+	}
+
+	g, err := b.Build(RootModulePath)
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(testBuiltinGraphBuilderOrphanDepsStr)
+	if actual != expected {
+		t.Fatalf("bad: %s", actual)
+	}
+}
+
 /*
 TODO: This exposes a really bad bug we need to fix after we merge
 the f-ast-branch. This bug still exists in master.
@@ -233,6 +276,16 @@ root
   module.foo.plan-destroy
 `
 
+const testBuiltinGraphBuilderOrphanDepsStr = `
+aws_instance.bar (orphan)
+  provider.aws
+aws_instance.foo (orphan)
+  aws_instance.bar (orphan)
+provider.aws
+provider.aws (close)
+  aws_instance.foo (orphan)
+`
+
 /*
 TODO: Commented out this const as it's likely this needs to
 be updated when the TestBuiltinGraphBuilder_modules test is

terraform/test-fixtures/graph-builder-orphan-deps/main.tf

@@ -0,0 +1 @@
+provider "aws" {}

terraform/transform_destroy.go

@@ -1,6 +1,8 @@
 package terraform
 
-import "github.com/hashicorp/terraform/dag"
+import (
+	"github.com/hashicorp/terraform/dag"
+)
 
 type GraphNodeDestroyMode byte
 
@@ -103,6 +105,12 @@ func (t *DestroyTransformer) transform(
 		nodeToCn[n] = cn
 		nodeToDn[cn] = n
 
+		// If the creation node is equal to the destroy node, then
+		// don't do any of the edge jump rope below.
+		if n.(interface{}) == cn.(interface{}) {
+			continue
+		}
+
 		// Add it to the graph
 		g.Add(n)
 

terraform/transform_orphan.go

@@ -298,6 +298,24 @@ func (n *graphNodeOrphanResource) dependableName() string {
 	return n.ResourceName
 }
 
+// GraphNodeDestroyable impl.
+func (n *graphNodeOrphanResource) DestroyNode(mode GraphNodeDestroyMode) GraphNodeDestroy {
+	if mode != DestroyPrimary {
+		return nil
+	}
+
+	return n
+}
+
+// GraphNodeDestroy impl.
+func (n *graphNodeOrphanResource) CreateBeforeDestroy() bool {
+	return false
+}
+
+func (n *graphNodeOrphanResource) CreateNode() dag.Vertex {
+	return n
+}
+
 // Same as graphNodeOrphanResource, but for flattening
 type graphNodeOrphanResourceFlat struct {
 	*graphNodeOrphanResource
@@ -313,3 +331,21 @@ func (n *graphNodeOrphanResourceFlat) Name() string {
 func (n *graphNodeOrphanResourceFlat) Path() []string {
 	return n.PathValue
 }
+
+// GraphNodeDestroyable impl.
+func (n *graphNodeOrphanResourceFlat) DestroyNode(mode GraphNodeDestroyMode) GraphNodeDestroy {
+	if mode != DestroyPrimary {
+		return nil
+	}
+
+	return n
+}
+
+// GraphNodeDestroy impl.
+func (n *graphNodeOrphanResourceFlat) CreateBeforeDestroy() bool {
+	return false
+}
+
+func (n *graphNodeOrphanResourceFlat) CreateNode() dag.Vertex {
+	return n
+}