go-by-test/sum/sum_test.go

package sum

import (
	"slices"
	"testing"
)

func TestSum(t *testing.T) {
	t.Run("collection of 5 numbers", func(t *testing.T) {
		numbers := []int{1, 2, 3, 4, 5}

		got := Sum(numbers)
		exp := 15

		if got != exp {
			t.Errorf("got %d, expected %d, given %v", got, exp, numbers)
		}
	})
}

func TestSumAll(t *testing.T) {
	got := SumAll([]int{1, 2}, []int{0, 9})
	exp := []int{3, 9}

	if !slices.Equal(got, exp) {
		t.Errorf("got %d, expected %d", got, exp)
	}
}

func TestSumAllTails(t *testing.T) {
	checkSums := func(t *testing.T, got, exp []int) {
		if !slices.Equal(got, exp) {
			t.Errorf("got %d, expected %d", got, exp)
		}
	}

	t.Run("make the sums of some slices", func(t *testing.T) {
		got := SumAllTails([]int{1, 2}, []int{0, 9})
		exp := []int{2, 9}

		checkSums(t, got, exp)
	})

	t.Run("safely sum empty slices", func(t *testing.T) {
		got := SumAllTails([]int{}, []int{3, 4, 5})
		exp := []int{0, 9}

		checkSums(t, got, exp)
	})
}