1package main
 2
 3import "reflect"
 4import "testing"
 5
 6func TestSum(test *testing.T) {
 7	test.Run("collection of 5 numbers", func(test *testing.T) {
 8		numbers := []int{1, 2, 3, 4, 5}
 9		got := Sum(numbers)
10		want := 15
11
12		if got != want {
13			test.Errorf("got %d want %d given, %v", got, want, numbers)
14		}
15	})
16
17	test.Run("collection of any size", func(test *testing.T) {
18		numbers := []int{1, 2, 3}
19		got := Sum(numbers)
20		want := 6
21
22		if got != want {
23			test.Errorf("got %d want %d given, %v", got, want, numbers)
24		}
25	})
26}
27
28func TestSumAll(t *testing.T) {
29	got := SumAll([]int{1, 2}, []int{0, 9})
30	want := []int{3, 9}
31
32	if !reflect.DeepEqual(got, want) {
33		t.Errorf("got %v want %v", got, want)
34	}
35}
36
37func TestSumAllTails(t *testing.T) {
38	checkSums := func(t *testing.T, got, want []int) {
39		t.Helper()
40		if !reflect.DeepEqual(got, want) {
41			t.Errorf("got %v want %v", got, want)
42		}
43	}
44
45	t.Run("make the sums of some slices", func(t *testing.T) {
46		got := SumAllTails([]int{1, 2}, []int{0, 9})
47		want := []int{2, 9}
48
49		checkSums(t, got, want)
50	})
51
52	t.Run("safely sum empty slices", func(t *testing.T) {
53		got := SumAllTails([]int{}, []int{3, 4, 5})
54		want := []int{0, 9}
55
56		checkSums(t, got, want)
57	})
58}