Add new test and update graph outputs

The the grandChild missing test has a provider declared in a child
module which is missing in a grandchildmodule. Verify that the
grandchild gets connected to the child provider, and they all are
connected to the root providers.

Update some test outputs to match the expected behavior of only adding
missing providers at the root level.

terraform/test-fixtures/transform-provider-missing-grandchild/main.tf

@@ -0,0 +1,3 @@
+module "sub" {
+    source = "./sub"
+}

terraform/test-fixtures/transform-provider-missing-grandchild/sub/main.tf

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

terraform/test-fixtures/transform-provider-missing-grandchild/sub/subsub/main.tf

@@ -0,0 +1,2 @@
+resource "foo_instance" "one" {}
+resource "bar_instance" "two" {}

terraform/transform_provider_test.go

@@ -3,6 +3,8 @@ package terraform
 import (
 	"strings"
 	"testing"
+
+	"github.com/hashicorp/terraform/dag"
 )
 
 func TestProviderTransformer(t *testing.T) {
@@ -199,6 +201,46 @@ func TestMissingProviderTransformer(t *testing.T) {
 	}
 }
 
+func TestMissingProviderTransformer_grandchildMissing(t *testing.T) {
+	mod := testModule(t, "transform-provider-missing-grandchild")
+
+	concrete := func(a *NodeAbstractProvider) dag.Vertex { return a }
+
+	g := Graph{Path: RootModulePath}
+	{
+		tf := &ConfigTransformer{Module: mod}
+		if err := tf.Transform(&g); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+
+	{
+		transform := &AttachResourceConfigTransformer{Module: mod}
+		if err := transform.Transform(&g); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+
+	{
+		transform := TransformProviders([]string{"aws", "foo", "bar"}, concrete, mod)
+		if err := transform.Transform(&g); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+	{
+		transform := &TransitiveReductionTransformer{}
+		if err := transform.Transform(&g); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(testTransformMissingGrandchildProviderStr)
+	if actual != expected {
+		t.Fatalf("expected:\n%s\n\ngot:\n%s", expected, actual)
+	}
+}
+
 func TestMissingProviderTransformer_moduleChild(t *testing.T) {
 	g := Graph{Path: RootModulePath}
 
@@ -304,7 +346,7 @@ func TestParentProviderTransformer(t *testing.T) {
 	actual := strings.TrimSpace(g.String())
 	expected := strings.TrimSpace(testTransformParentProviderStr)
 	if actual != expected {
-		t.Fatalf("bad:\n\n%s", actual)
+		t.Fatalf("expected:\n%s\n\ngot:\n%s", expected, actual)
 	}
 }
 
@@ -433,6 +475,23 @@ provider.foo (close)
   provider.foo
 `
 
+const testTransformMissingGrandchildProviderStr = `
+module.sub.module.subsub.bar_instance.two
+  module.sub.module.subsub.provider.bar
+  provider.bar
+module.sub.module.subsub.foo_instance.one
+  module.sub.module.subsub.provider.foo
+  provider.foo
+module.sub.module.subsub.provider.bar
+  provider.bar
+module.sub.module.subsub.provider.foo
+  provider.foo
+module.sub.provider.foo (disabled)
+  provider.foo
+provider.bar
+provider.foo
+`
+
 const testTransformMissingProviderModuleChildStr = `
 module.moo.foo_instance.qux (import id: bar)
 module.moo.provider.foo
@@ -448,16 +507,12 @@ provider.foo
 
 const testTransformParentProviderStr = `
 module.moo.foo_instance.qux (import id: bar)
-module.moo.provider.foo
   provider.foo
 provider.foo
 `
 
 const testTransformParentProviderModuleGrandchildStr = `
 module.a.module.b.foo_instance.qux (import id: bar)
-module.a.module.b.provider.foo
-  module.a.provider.foo
-module.a.provider.foo
   provider.foo
 provider.foo
 `