From f4f297347f5667fb64fc49f3da8a5464f1021816 Mon Sep 17 00:00:00 2001
From: ryane <ryanesc@gmail.com>
Date: Tue, 18 Oct 2016 12:14:56 -0400
Subject: [PATCH] groups: add graph.IsRoot

---
 graph/ids.go                        |  5 +++++
 graph/ids_test.go                   | 13 +++++++++++++
 graph/merge_duplicates.go           |  2 +-
 load/dependencyresolver.go          |  4 ++--
 load/resource.go                    |  2 +-
 render/preprocessor/preprocessor.go |  2 +-
 render/render.go                    |  2 +-
 render/renderer.go                  |  2 +-
 8 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/graph/ids.go b/graph/ids.go
index 7e37680fa..cb59d2e6c 100644
--- a/graph/ids.go
+++ b/graph/ids.go
@@ -48,3 +48,8 @@ func BaseID(id string) string {
 func IsDescendentID(parent, child string) bool {
 	return parent != child && strings.HasPrefix(child, parent)
 }
+
+// IsRoot checks if the ID identifies the root
+func IsRoot(id string) bool {
+	return id == "root"
+}
diff --git a/graph/ids_test.go b/graph/ids_test.go
index d296a57f0..0a1075d7b 100644
--- a/graph/ids_test.go
+++ b/graph/ids_test.go
@@ -68,3 +68,16 @@ func TestIsDescendentIDNot(t *testing.T) {
 
 	assert.False(t, graph.IsDescendentID("a/b", "a/c"))
 }
+
+// TestIsRoot tests the IsRoot function
+func TestIsRoot(t *testing.T) {
+	t.Parallel()
+
+	t.Run("is root", func(t *testing.T) {
+		assert.True(t, graph.IsRoot("root"))
+	})
+
+	t.Run("is not root", func(t *testing.T) {
+		assert.False(t, graph.IsRoot("root/module.test"))
+	})
+}
diff --git a/graph/merge_duplicates.go b/graph/merge_duplicates.go
index a23d537a8..55c288450 100644
--- a/graph/merge_duplicates.go
+++ b/graph/merge_duplicates.go
@@ -35,7 +35,7 @@ func MergeDuplicates(ctx context.Context, g *Graph, skip SkipMergeFunc) (*Graph,
 	logger := logging.GetLogger(ctx).WithField("function", "MergeDuplicates")
 
 	return g.RootFirstTransform(ctx, func(meta *node.Node, out *Graph) error {
-		if meta.ID == "root" {
+		if IsRoot(meta.ID) {
 			return nil
 		}
 
diff --git a/load/dependencyresolver.go b/load/dependencyresolver.go
index 8f7a0dadf..21725fce7 100644
--- a/load/dependencyresolver.go
+++ b/load/dependencyresolver.go
@@ -143,7 +143,7 @@ func getXrefs(g *graph.Graph, id string, node *parse.Node) (out []string, err er
 }
 
 func getPeerVertex(src, dst string) (string, bool) {
-	if dst == "." || dst == "root" {
+	if dst == "." || graph.IsRoot(dst) {
 		return "", false
 	}
 	if graph.AreSiblingIDs(src, dst) {
@@ -153,7 +153,7 @@ func getPeerVertex(src, dst string) (string, bool) {
 }
 
 func getNearestAncestor(g *graph.Graph, id, node string) (string, bool) {
-	if id == "root" || id == "" || id == "." {
+	if graph.IsRoot(id) || id == "" || id == "." {
 		return "", false
 	}
 
diff --git a/load/resource.go b/load/resource.go
index 35882139a..86916b33d 100644
--- a/load/resource.go
+++ b/load/resource.go
@@ -49,7 +49,7 @@ func SetResources(ctx context.Context, g *graph.Graph) (*graph.Graph, error) {
 	logger.Debug("loading resources")
 
 	return g.Transform(ctx, func(meta *node.Node, out *graph.Graph) error {
-		if meta.ID == "root" {
+		if graph.IsRoot(meta.ID) {
 			return nil
 		}
 
diff --git a/render/preprocessor/preprocessor.go b/render/preprocessor/preprocessor.go
index 608594f7f..995c09999 100644
--- a/render/preprocessor/preprocessor.go
+++ b/render/preprocessor/preprocessor.go
@@ -181,7 +181,7 @@ func VertexSplitTraverse(g *graph.Graph, toFind string, startingNode string, sto
 // VertexSplitTraverse and will cause vertex splitting to propogate upwards
 // until it encounters a module
 func TraverseUntilModule(g *graph.Graph, id string) bool {
-	if id == "root" {
+	if graph.IsRoot(id) {
 		return true
 	}
 	elemMeta, ok := g.Get(id)
diff --git a/render/render.go b/render/render.go
index 7cee37c98..aa083da81 100644
--- a/render/render.go
+++ b/render/render.go
@@ -76,7 +76,7 @@ func Pipeline(g *graph.Graph, id string, factory *Factory, top Values) executor.
 // the node is a valide resource.Resource return it.  If it's not root and not a
 // resource.Resource return an error.
 func (p pipelineGen) maybeTransformRoot(idi interface{}) (interface{}, error) {
-	if p.ID == "root" {
+	if graph.IsRoot(p.ID) {
 		return module.NewPreparer(p.Top), nil
 	}
 	if res, ok := idi.(resource.Resource); ok {
diff --git a/render/renderer.go b/render/renderer.go
index 3adf5903a..b178368fd 100644
--- a/render/renderer.go
+++ b/render/renderer.go
@@ -74,7 +74,7 @@ func (r *Renderer) Render(name, src string) (string, error) {
 }
 
 func getNearestAncestor(g *graph.Graph, id, node string) (string, bool) {
-	if node == "root" || node == "" {
+	if graph.IsRoot(node) || node == "" {
 		return "", false
 	}
 	siblingID := graph.SiblingID(id, node)