diff --git a/db.go b/db.go
index c7edfbb..2955130 100644
--- a/db.go
+++ b/db.go
@@ -92,7 +92,6 @@ func NewFileDB(dir string, mkdir bool) (*FileDB, error) {
 // characters.
 func (f *FileDB) linkPath(short string) string {
 	name := linkID(short)
-	name = strings.ReplaceAll(name, ".", "%2e")
 	return filepath.Join(f.dir, name)
 }
 
@@ -144,7 +143,7 @@ func (f *FileDB) Save(link *Link) error {
 }
 
 func (f *FileDB) LoadStats() (ClickStats, error) {
-	links, err := db.LoadAll()
+	links, err := f.LoadAll()
 	if err != nil {
 		return nil, err
 	}
diff --git a/db_test.go b/db_test.go
new file mode 100644
index 0000000..6d08ac0
--- /dev/null
+++ b/db_test.go
@@ -0,0 +1,140 @@
+package main
+
+import (
+	"path"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/google/go-cmp/cmp/cmpopts"
+)
+
+func Test_FileDB_linkPath(t *testing.T) {
+	tests := []struct {
+		short, want string
+	}{
+		{"foo", "foo"},
+		{"FOO", "foo"},
+		{"foo-bar", "foobar"},
+		{"foo.bar", "foo.bar"},
+		{"foo/bar", "foo%2Fbar"},
+	}
+
+	db := &FileDB{dir: "/tmp"}
+	for _, tt := range tests {
+		want := "/tmp/" + tt.want
+		if got := db.linkPath(tt.short); got != want {
+			t.Errorf("linkPath(%q) got %q, want %q", tt.short, got, want)
+		}
+	}
+}
+
+// Test saving and loading links for FileDB
+func Test_FileDB_SaveLoadLinks(t *testing.T) {
+	db, err := NewFileDB(t.TempDir(), false)
+	if err != nil {
+		t.Error(err)
+	}
+
+	testSaveAndLoadLinks(t, db)
+}
+
+// Test saving and loading stats for FileDB
+func Test_FileDB_SaveLoadStats(t *testing.T) {
+	db, err := NewFileDB(t.TempDir(), false)
+	if err != nil {
+		t.Error(err)
+	}
+
+	testSaveAndLoadStats(t, db)
+}
+
+// Test saving and loading links for SQLiteDB
+func Test_SQLiteDB_SaveLoadLinks(t *testing.T) {
+	db, err := NewSQLiteDB(path.Join(t.TempDir(), "links.db"))
+	if err != nil {
+		t.Error(err)
+	}
+
+	testSaveAndLoadLinks(t, db)
+}
+
+// Test saving and loading stats for SQLiteDB
+func Test_SQLiteDB_SaveLoadStats(t *testing.T) {
+	db, err := NewSQLiteDB(path.Join(t.TempDir(), "links.db"))
+	if err != nil {
+		t.Error(err)
+	}
+
+	testSaveAndLoadStats(t, db)
+}
+
+func testSaveAndLoadLinks(t *testing.T, db DB) {
+	links := []*Link{
+		{Short: "short", Long: "long"},
+		{Short: "Foo.Bar", Long: "long"},
+	}
+
+	for _, link := range links {
+		if err := db.Save(link); err != nil {
+			t.Error(err)
+		}
+		got, err := db.Load(link.Short)
+		if err != nil {
+			t.Error(err)
+		}
+
+		if !cmp.Equal(got, link) {
+			t.Errorf("db save and load got %v, want %v", *got, *link)
+		}
+	}
+
+	got, err := db.LoadAll()
+	if err != nil {
+		t.Error(err)
+	}
+
+	sortLinks := cmpopts.SortSlices(func(a, b *Link) bool {
+		return a.Short < b.Short
+	})
+	if !cmp.Equal(got, links, sortLinks) {
+		t.Errorf("db.LoadAll got %v, want %v", got, links)
+	}
+}
+
+func testSaveAndLoadStats(t *testing.T, db DB) {
+	// preload some links
+	links := []*Link{
+		{Short: "a"},
+		{Short: "b"},
+	}
+	for _, link := range links {
+		if err := db.Save(link); err != nil {
+			t.Error(err)
+		}
+	}
+
+	// stats to record and then retrieve
+	stats := []ClickStats{
+		{"a": 1},
+		{"b": 1},
+		{"a": 1, "b": 2},
+	}
+	want := ClickStats{
+		"a": 2,
+		"b": 3,
+	}
+
+	for _, s := range stats {
+		if err := db.SaveStats(s); err != nil {
+			t.Error(err)
+		}
+	}
+
+	got, err := db.LoadStats()
+	if err != nil {
+		t.Error(err)
+	}
+	if !cmp.Equal(got, want) {
+		t.Errorf("db.LoadStats got %v, want %v", got, want)
+	}
+}