✨ (sum_tail_test): add test for empty slice

Author: yuanyu90221

arrays-and-slices/sum_test.go

@@ -49,11 +49,19 @@ func TestSumAll(t *testing.T) {
 }
 
 func TestSumAllTails(t *testing.T) {
+	t.Run("make the sums of some slices", func(t *testing.T) {
+		got := SumAllTails([]int{1, 2}, []int{0, 9})
+		want := []int{2, 9}
 
-	got := SumAllTails([]int{1, 2}, []int{0, 9})
-	want := []int{2, 9}
-
-	if !reflect.DeepEqual(got, want) {
-		t.Errorf("got %v, want %v", got, want)
-	}
+		if !reflect.DeepEqual(got, want) {
+			t.Errorf("got %v, want %v", got, want)
+		}
+	})
+	t.Run("safely sum empty slices", func(t *testing.T) {
+		got := SumAllTails([]int{}, []int{3, 4, 5})
+		want := []int{0, 9}
+		if !reflect.DeepEqual(got, want) {
+			t.Errorf("got %v, want %v", got, want)
+		}
+	})
 }