diff --git a/go/algorithm/cartesian/cartesian_test.go b/go/algorithm/cartesian/cartesian_test.go
new file mode 100644
index 0000000..5911ecc
--- /dev/null
+++ b/go/algorithm/cartesian/cartesian_test.go
@@ -0,0 +1,48 @@
+package cartesian
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestProduct(t *testing.T) {
+	for i, te := range []struct {
+		data [][]string
+		want [][]string
+	}{
+		{
+			data: [][]string{
+				{"a", "b"},
+				{"c", "d"},
+			},
+			want: [][]string{
+				{"a", "c"},
+				{"a", "d"},
+				{"b", "c"},
+				{"b", "d"},
+			},
+		},
+		{
+			data: [][]string{
+				{"a", "b"},
+			},
+			want: [][]string{
+				{"a"},
+				{"b"},
+			},
+		},
+		{
+			data: [][]string{},
+			want: nil,
+		},
+	} {
+		t.Run(fmt.Sprintf("%d", i), func(t *testing.T) {
+			got := Product(te.data...)
+			if diff := cmp.Diff(te.want, got); diff != "" {
+				t.Fatalf("Diff:\n%s", diff)
+			}
+		})
+	}
+}