terraform: add module destroy node to graph

terraform/graph_config_node_module.go

@@ -63,6 +63,14 @@ func (n *GraphNodeConfigModule) Expand(b GraphBuilder) (GraphNodeSubgraph, error
 		return nil, err
 	}
 
+	{
+		// Add the destroy marker to the graph
+		t := &ModuleDestroyTransformer{}
+		if err := t.Transform(graph); err != nil {
+			return nil, err
+		}
+	}
+
 	// Build the actual subgraph node
 	return &graphNodeModuleExpanded{
 		Original:  n,
@@ -148,15 +156,6 @@ func (n *graphNodeModuleExpanded) EvalTree() EvalNode {
 				Config:    &resourceConfig,
 				Variables: n.Variables,
 			},
-
-			&EvalOpFilter{
-				Ops: []walkOperation{walkPlanDestroy},
-				Node: &EvalSequence{
-					Nodes: []EvalNode{
-						&EvalDiffDestroyModule{Path: n.Graph.Path},
-					},
-				},
-			},
 		},
 	}
 }

terraform/graph_config_node_module_test.go

@@ -73,8 +73,10 @@ aws_instance.bar
 aws_instance.foo
   module inputs
 module inputs
+plan-destroy
 `
 
 const testGraphNodeModuleExpandFlattenStr = `
 aws_instance.foo
+plan-destroy
 `

terraform/transform_flatten_test.go

@@ -74,6 +74,7 @@ module.child.aws_instance.child
   module.child.var.var
 module.child.output.output
   module.child.aws_instance.child
+module.child.plan-destroy
 module.child.var.var
   aws_instance.parent
 `
@@ -88,6 +89,7 @@ module.child.aws_instance.child
   module.child.var.var
 module.child.output.output
   module.child.aws_instance.child
+module.child.plan-destroy
 module.child.var.var
   aws_instance.parent
 `

terraform/transform_module.go

@@ -1,6 +1,7 @@
 package terraform
 
 import (
+	"fmt"
 	"github.com/hashicorp/terraform/dag"
 )
 
@@ -42,21 +43,10 @@ func (t *ModuleDestroyTransformer) Transform(g *Graph) error {
 	// Create the node
 	n := &graphNodeModuleDestroy{Path: g.Path}
 
-	// Add it to the graph
+	// Add it to the graph. We don't need any edges because
+	// it can happen whenever.
 	g.Add(n)
 
-	// Connect the inputs to the bottom of the graph so that it happens
-	// first.
-	for _, v := range g.Vertices() {
-		if v == n {
-			continue
-		}
-
-		if g.DownEdges(v).Len() == 0 {
-			g.Connect(dag.BasicEdge(v, n))
-		}
-	}
-
 	return nil
 }
 
@@ -65,7 +55,7 @@ type graphNodeModuleDestroy struct {
 }
 
 func (n *graphNodeModuleDestroy) Name() string {
-	return "module destroy (for plan)"
+	return "plan-destroy"
 }
 
 // GraphNodeEvalable impl.
@@ -76,6 +66,29 @@ func (n *graphNodeModuleDestroy) EvalTree() EvalNode {
 	}
 }
 
+// GraphNodeFlattenable impl.
+func (n *graphNodeModuleDestroy) Flatten(p []string) (dag.Vertex, error) {
+	return &graphNodeModuleDestroyFlat{
+		graphNodeModuleDestroy: n,
+		PathValue:              p,
+	}, nil
+}
+
+type graphNodeModuleDestroyFlat struct {
+	*graphNodeModuleDestroy
+
+	PathValue []string
+}
+
+func (n *graphNodeModuleDestroyFlat) Name() string {
+	return fmt.Sprintf(
+		"%s.%s", modulePrefixStr(n.PathValue), n.graphNodeModuleDestroy.Name())
+}
+
+func (n *graphNodeModuleDestroyFlat) Path() []string {
+	return n.PathValue
+}
+
 type graphNodeModuleInput struct {
 	Variables map[string]string
 }