fix new digester

Signed-off-by: zhaque44 <haque.zubair@gmail.com>

internal/index/digest_test.go

@@ -59,27 +59,31 @@ func TestWithIndex(t *testing.T) {
 }
 
 func TestNewDigester(t *testing.T) {
+	g := NewWithT(t)
+
 	t.Run("default", func(t *testing.T) {
-		g := NewWithT(t)
-
 		d := NewDigester()
-
 		g.Expect(d).ToNot(BeNil())
-		g.Expect(d.index).ToNot(BeNil())
+		g.Expect(d.index).To(BeEmpty())
 		g.Expect(d.digests).ToNot(BeNil())
 	})
 
 	t.Run("with index", func(t *testing.T) {
-		g := NewWithT(t)
-
-		i := map[string]string{"foo": "bar"}
-		d := NewDigester(WithIndex(i))
-
+		initialIndex := map[string]string{"foo": "bar"}
+		d := NewDigester(WithIndex(initialIndex))
 		g.Expect(d).ToNot(BeNil())
-		g.Expect(d.index).To(Equal(i))
+		g.Expect(d.index).To(Equal(initialIndex))
 		g.Expect(d.digests).ToNot(BeNil())
 	})
 
+	t.Run("handles multiple WithIndex options, applying last one", func(t *testing.T) {
+		firstIndex := map[string]string{"a": "b"}
+		secondIndex := map[string]string{"c": "d"}
+		d := NewDigester(WithIndex(firstIndex), WithIndex(secondIndex))
+		g.Expect(d.index).To(Equal(secondIndex))
+	})
+}
+
 	t.Run("handles multiple WithIndex options, applying last one", func(t *testing.T) {
 		g := NewWithT(t)
 		firstIndex := map[string]string{"a": "b"}