diff --git a/serialfile_test.go b/serialfile_test.go
new file mode 100644
index 0000000..748ba16
--- /dev/null
+++ b/serialfile_test.go
@@ -0,0 +1,126 @@
+package files
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func isPathHidden(p string) bool {
+	return strings.HasPrefix(p, ".") || strings.Contains(p, "/.")
+}
+
+func TestSerialFile(t *testing.T) {
+	t.Run("Hidden", func(t *testing.T) { testSerialFile(t, true) })
+	t.Run("NotHidden", func(t *testing.T) { testSerialFile(t, false) })
+}
+
+func testSerialFile(t *testing.T, hidden bool) {
+	tmppath, err := ioutil.TempDir("", "files-test")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmppath)
+
+	expected := map[string]string{
+		"1":      "Some text!\n",
+		"2":      "beep",
+		"3":      "",
+		"4":      "boop",
+		"5":      "",
+		"5/a":    "foobar",
+		".6":     "thing",
+		"7":      "",
+		"7/.foo": "bla",
+		".8":     "",
+		".8/foo": "bla",
+	}
+
+	for p, c := range expected {
+		path := filepath.Join(tmppath, p)
+		if c != "" {
+			continue
+		}
+		if err := os.MkdirAll(path, 0777); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	for p, c := range expected {
+		path := filepath.Join(tmppath, p)
+		if c == "" {
+			continue
+		}
+		if err := ioutil.WriteFile(path, []byte(c), 0666); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	stat, err := os.Stat(tmppath)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sf, err := NewSerialFile(tmppath, hidden, stat)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer sf.Close()
+
+	rootFound := false
+	err = Walk(sf, func(path string, nd Node) error {
+		defer nd.Close()
+
+		// root node.
+		if path == "" {
+			if rootFound {
+				return fmt.Errorf("found root twice")
+			}
+			if sf != nd {
+				return fmt.Errorf("wrong root")
+			}
+			rootFound = true
+			return nil
+		}
+
+		if !hidden && isPathHidden(path) {
+			return fmt.Errorf("found a hidden file")
+		}
+
+		data, ok := expected[path]
+		if !ok {
+			return fmt.Errorf("expected something at %q", path)
+		}
+		delete(expected, path)
+
+		switch nd := nd.(type) {
+		case *Symlink:
+			return fmt.Errorf("didn't expect a symlink")
+		case Directory:
+			if data != "" {
+				return fmt.Errorf("expected a directory at %q", path)
+			}
+		case File:
+			actual, err := ioutil.ReadAll(nd)
+			if err != nil {
+				return err
+			}
+			if string(actual) != data {
+				return fmt.Errorf("expected %q, got %q", data, string(actual))
+			}
+		}
+		return nil
+	})
+	if !rootFound {
+		t.Fatal("didn't find the root")
+	}
+	for p := range expected {
+		if !hidden && isPathHidden(p) {
+			continue
+		}
+		t.Errorf("missed %q", p)
+	}
+}