From 414cbbe808c72f691bed588d9f0f2574934f71b8 Mon Sep 17 00:00:00 2001
From: James Bardin <j.bardin@gmail.com>
Date: Mon, 16 Dec 2019 17:45:34 -0500
Subject: [PATCH] NodeDestroyResource does not need a provider

The resource cleanup node does not need a provider. We can't directly
remove the ProvidedBy method, but this node only needs to be eval-able
so we can remove all the NodeAbstractResource methods at once.
---
 terraform/graph_builder_apply_test.go         | 42 +++++++++++++++++++
 terraform/node_resource_destroy.go            | 29 ++-----------
 .../graph-builder-orphan-alias/main.tf        |  3 ++
 3 files changed, 49 insertions(+), 25 deletions(-)
 create mode 100644 terraform/testdata/graph-builder-orphan-alias/main.tf

diff --git a/terraform/graph_builder_apply_test.go b/terraform/graph_builder_apply_test.go
index af1aa9779..98bab2377 100644
--- a/terraform/graph_builder_apply_test.go
+++ b/terraform/graph_builder_apply_test.go
@@ -600,6 +600,48 @@ test_object.b
 	}
 }
 
+// The orphan clean up node should not be connected to a provider
+func TestApplyGraphBuilder_orphanedWithProvider(t *testing.T) {
+	changes := &plans.Changes{
+		Resources: []*plans.ResourceInstanceChangeSrc{
+			{
+				Addr: mustResourceInstanceAddr("test_object.A"),
+				ChangeSrc: plans.ChangeSrc{
+					Action: plans.Delete,
+				},
+			},
+		},
+	}
+
+	state := states.NewState()
+	root := state.EnsureModule(addrs.RootModuleInstance)
+	root.SetResourceInstanceCurrent(
+		mustResourceInstanceAddr("test_object.A").Resource,
+		&states.ResourceInstanceObjectSrc{
+			Status:    states.ObjectReady,
+			AttrsJSON: []byte(`{"id":"A"}`),
+		},
+		mustProviderConfig("provider.test.foo"),
+	)
+
+	b := &ApplyGraphBuilder{
+		Config:     testModule(t, "graph-builder-orphan-alias"),
+		Changes:    changes,
+		Components: simpleMockComponentFactory(),
+		Schemas:    simpleTestSchemas(),
+		State:      state,
+	}
+
+	g, err := b.Build(addrs.RootModuleInstance)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// The cleanup node has no state or config of its own, so would create a
+	// default provider which we don't want.
+	testGraphNotContains(t, g, "provider.test")
+}
+
 const testApplyGraphBuilderStr = `
 meta.count-boundary (EachMode fixup)
   module.child.test_object.other
diff --git a/terraform/node_resource_destroy.go b/terraform/node_resource_destroy.go
index ca2267e47..c5042436d 100644
--- a/terraform/node_resource_destroy.go
+++ b/terraform/node_resource_destroy.go
@@ -277,36 +277,15 @@ func (n *NodeDestroyResourceInstance) EvalTree() EvalNode {
 // leaving skeleton resource objects in state after their instances have
 // all been destroyed.
 type NodeDestroyResource struct {
-	*NodeAbstractResource
+	NodeAbstractResource *NodeAbstractResource
 }
 
 var (
-	_ GraphNodeResource      = (*NodeDestroyResource)(nil)
-	_ GraphNodeReferenceable = (*NodeDestroyResource)(nil)
-	_ GraphNodeReferencer    = (*NodeDestroyResource)(nil)
-	_ GraphNodeEvalable      = (*NodeDestroyResource)(nil)
+	_ GraphNodeEvalable = (*NodeDestroyResource)(nil)
 )
 
 func (n *NodeDestroyResource) Name() string {
-	return n.ResourceAddr().String() + " (clean up state)"
-}
-
-// GraphNodeReferenceable, overriding NodeAbstractResource
-func (n *NodeDestroyResource) ReferenceableAddrs() []addrs.Referenceable {
-	// NodeDestroyResource doesn't participate in references: the graph
-	// builder that created it should ensure directly that it already depends
-	// on every other node related to its resource, without relying on
-	// references.
-	return nil
-}
-
-// GraphNodeReferencer, overriding NodeAbstractResource
-func (n *NodeDestroyResource) References() []*addrs.Reference {
-	// NodeDestroyResource doesn't participate in references: the graph
-	// builder that created it should ensure directly that it already depends
-	// on every other node related to its resource, without relying on
-	// references.
-	return nil
+	return n.NodeAbstractResource.ResourceAddr().String() + " (clean up state)"
 }
 
 // GraphNodeEvalable
@@ -316,6 +295,6 @@ func (n *NodeDestroyResource) EvalTree() EvalNode {
 	// leftover husk of a resource in state after all of the child instances
 	// and their objects were destroyed.
 	return &EvalForgetResourceState{
-		Addr: n.ResourceAddr().Resource,
+		Addr: n.NodeAbstractResource.ResourceAddr().Resource,
 	}
 }
diff --git a/terraform/testdata/graph-builder-orphan-alias/main.tf b/terraform/testdata/graph-builder-orphan-alias/main.tf
new file mode 100644
index 000000000..039881847
--- /dev/null
+++ b/terraform/testdata/graph-builder-orphan-alias/main.tf
@@ -0,0 +1,3 @@
+provider "test" {
+  alias = "foo"
+}