Move Follow symlink to pkg

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

symlink/fs_test.go

@@ -0,0 +1,108 @@
+package symlink
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func abs(t *testing.T, p string) string {
+	o, err := filepath.Abs(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return o
+}
+
+func TestFollowSymLinkNormal(t *testing.T) {
+	link := "testdata/fs/a/d/c/data"
+
+	rewrite, err := FollowSymlinkInScope(link, "testdata")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if expected := abs(t, "testdata/b/c/data"); expected != rewrite {
+		t.Fatalf("Expected %s got %s", expected, rewrite)
+	}
+}
+
+func TestFollowSymLinkUnderLinkedDir(t *testing.T) {
+	dir, err := ioutil.TempDir("", "docker-fs-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	os.Mkdir(filepath.Join(dir, "realdir"), 0700)
+	os.Symlink("realdir", filepath.Join(dir, "linkdir"))
+
+	linkDir := filepath.Join(dir, "linkdir", "foo")
+	dirUnderLinkDir := filepath.Join(dir, "linkdir", "foo", "bar")
+	os.MkdirAll(dirUnderLinkDir, 0700)
+
+	rewrite, err := FollowSymlinkInScope(dirUnderLinkDir, linkDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if rewrite != dirUnderLinkDir {
+		t.Fatalf("Expected %s got %s", dirUnderLinkDir, rewrite)
+	}
+}
+
+func TestFollowSymLinkRandomString(t *testing.T) {
+	if _, err := FollowSymlinkInScope("toto", "testdata"); err == nil {
+		t.Fatal("Random string should fail but didn't")
+	}
+}
+
+func TestFollowSymLinkLastLink(t *testing.T) {
+	link := "testdata/fs/a/d"
+
+	rewrite, err := FollowSymlinkInScope(link, "testdata")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if expected := abs(t, "testdata/b"); expected != rewrite {
+		t.Fatalf("Expected %s got %s", expected, rewrite)
+	}
+}
+
+func TestFollowSymLinkRelativeLink(t *testing.T) {
+	link := "testdata/fs/a/e/c/data"
+
+	rewrite, err := FollowSymlinkInScope(link, "testdata")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if expected := abs(t, "testdata/fs/b/c/data"); expected != rewrite {
+		t.Fatalf("Expected %s got %s", expected, rewrite)
+	}
+}
+
+func TestFollowSymLinkRelativeLinkScope(t *testing.T) {
+	link := "testdata/fs/a/f"
+
+	rewrite, err := FollowSymlinkInScope(link, "testdata")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if expected := abs(t, "testdata/test"); expected != rewrite {
+		t.Fatalf("Expected %s got %s", expected, rewrite)
+	}
+
+	link = "testdata/fs/b/h"
+
+	rewrite, err = FollowSymlinkInScope(link, "testdata")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if expected := abs(t, "testdata/root"); expected != rewrite {
+		t.Fatalf("Expected %s got %s", expected, rewrite)
+	}
+}