config/module: Can look up Child with Tree.Child

config/module/test-fixtures/child/foo/bar/main.tf

@@ -0,0 +1,2 @@
+# Hello
+

config/module/test-fixtures/child/foo/main.tf

@@ -0,0 +1,5 @@
+# Hello
+
+module "bar" {
+    source = "./bar"
+}

config/module/test-fixtures/child/main.tf

@@ -0,0 +1,5 @@
+# Hello
+
+module "foo" {
+    source = "./foo"
+}

config/module/tree.go

@@ -67,6 +67,24 @@ func (t *Tree) Config() *config.Config {
 	return t.config
 }
 
+// Child returns the child with the given path (by name).
+func (t *Tree) Child(path []string) *Tree {
+	if len(path) == 0 {
+		return nil
+	}
+
+	c := t.Children()[path[0]]
+	if c == nil {
+		return nil
+	}
+
+	if len(path) == 1 {
+		return c
+	}
+
+	return c.Child(path[1:])
+}
+
 // Children returns the children of this tree (the modules that are
 // imported by this root).
 //

config/module/tree_test.go

@@ -6,6 +6,28 @@ import (
 	"testing"
 )
 
+func TestTreeChild(t *testing.T) {
+	storage := testStorage(t)
+	tree := NewTree("", testConfig(t, "child"))
+	if err := tree.Load(storage, GetModeGet); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	// Should be able to get the foo child
+	if c := tree.Child([]string{"foo"}); c == nil {
+		t.Fatal("should not be nil")
+	} else if c.Name() != "foo" {
+		t.Fatalf("bad: %#v", c.Name())
+	}
+
+	// Should be able to get the nested child
+	if c := tree.Child([]string{"foo", "bar"}); c == nil {
+		t.Fatal("should not be nil")
+	} else if c.Name() != "bar" {
+		t.Fatalf("bad: %#v", c.Name())
+	}
+}
+
 func TestTreeLoad(t *testing.T) {
 	storage := testStorage(t)
 	tree := NewTree("", testConfig(t, "basic"))