moving integration tests to graph unit tests

Addresses #12255
Signed-off-by: Srini Brahmaroutu <srbrahma@us.ibm.com>

graph/graph_test.go

@@ -1,4 +1,4 @@
-package docker
+package graph
 
 import (
 	"errors"
@@ -11,9 +11,7 @@ import (
 
 	"github.com/docker/docker/autogen/dockerversion"
 	"github.com/docker/docker/daemon/graphdriver"
-	"github.com/docker/docker/graph"
 	"github.com/docker/docker/image"
-	"github.com/docker/docker/pkg/archive"
 	"github.com/docker/docker/pkg/stringid"
 )
 
@@ -47,6 +45,7 @@ func TestMount(t *testing.T) {
 	if _, err := driver.Get(image.ID, ""); err != nil {
 		t.Fatal(err)
 	}
+
 }
 
 func TestInit(t *testing.T) {
@@ -166,18 +165,6 @@ func TestDeletePrefix(t *testing.T) {
 	assertNImages(graph, t, 0)
 }
 
-func createTestImage(graph *graph.Graph, t *testing.T) *image.Image {
-	archive, err := fakeTar()
-	if err != nil {
-		t.Fatal(err)
-	}
-	img, err := graph.Create(archive, "", "", "Test image", "", nil, nil)
-	if err != nil {
-		t.Fatal(err)
-	}
-	return img
-}
-
 func TestDelete(t *testing.T) {
 	graph, _ := tempGraph(t)
 	defer nukeGraph(graph)
@@ -277,11 +264,19 @@ func TestByParent(t *testing.T) {
 	}
 }
 
-/*
- * HELPER FUNCTIONS
- */
+func createTestImage(graph *Graph, t *testing.T) *image.Image {
+	archive, err := fakeTar()
+	if err != nil {
+		t.Fatal(err)
+	}
+	img, err := graph.Create(archive, "", "", "Test image", "", nil, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return img
+}
 
-func assertNImages(graph *graph.Graph, t *testing.T, n int) {
+func assertNImages(graph *Graph, t *testing.T, n int) {
 	if images, err := graph.Map(); err != nil {
 		t.Fatal(err)
 	} else if actualN := len(images); actualN != n {
@@ -289,7 +284,7 @@ func assertNImages(graph *graph.Graph, t *testing.T, n int) {
 	}
 }
 
-func tempGraph(t *testing.T) (*graph.Graph, graphdriver.Driver) {
+func tempGraph(t *testing.T) (*Graph, graphdriver.Driver) {
 	tmp, err := ioutil.TempDir("", "docker-graph-")
 	if err != nil {
 		t.Fatal(err)
@@ -298,22 +293,14 @@ func tempGraph(t *testing.T) (*graph.Graph, graphdriver.Driver) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	graph, err := graph.NewGraph(tmp, driver)
+	graph, err := NewGraph(tmp, driver)
 	if err != nil {
 		t.Fatal(err)
 	}
 	return graph, driver
 }
 
-func nukeGraph(graph *graph.Graph) {
+func nukeGraph(graph *Graph) {
 	graph.Driver().Cleanup()
 	os.RemoveAll(graph.Root)
 }
-
-func testArchive(t *testing.T) archive.Archive {
-	archive, err := fakeTar()
-	if err != nil {
-		t.Fatal(err)
-	}
-	return archive
-}