learn_mqtt_go/clock/clock_test.go

package clock

import (
	"reflect"
	"testing"
)

func assertClocksEqual(t testing.TB, got, want []int) {
	t.Helper()

	if !reflect.DeepEqual(got, want) {
		t.Errorf("Error: got %v want %v", got, want)
	}

}

func TestVectorClock(t *testing.T) {
	got := NewVectorClock(2)
	want := VectorClock{clock: []int{0, 0}}

	assertClocksEqual(t, got.GetClock(), want.GetClock())

}

func TestArrayToVectorClock(t *testing.T) {

	t.Run("from empty slice", func(t *testing.T) {
		got := ArrayToVectorClock([]int{})
		want := VectorClock{
			clock: []int{},
		}

		if len(got.GetClock()) != 0 {
			t.Errorf("Expected VectorClock.clock to be of length zero.")
		}

		if !reflect.DeepEqual(got.GetClock(), want.GetClock()) {
			t.Errorf("Error: got %v want %v", got.GetClock(), want.GetClock())
		}
	})

	t.Run("from zero slice", func(t *testing.T) {
		got := ArrayToVectorClock(make([]int, 6))
		want := VectorClock{
			clock: []int{0, 0, 0, 0, 0, 0},
		}

		assertClocksEqual(t, got.GetClock(), want.GetClock())
	})

	t.Run("from start clock", func(t *testing.T) {
		want := NewVectorClock(3)
		got := ArrayToVectorClock(want.GetClock())

		assertClocksEqual(t, got.GetClock(), want.GetClock())
	})

	t.Run("from a populated clock", func(t *testing.T) {
		want := VectorClock{
			clock: []int{2, 3},
		}
		got := ArrayToVectorClock(want.GetClock())
		assertClocksEqual(t, got.GetClock(), want.GetClock())
	})

	t.Run("from a slice that is then modified", func(t *testing.T) {
		initial_a := []int{1, 2, 3, 4}
		got := ArrayToVectorClock(initial_a)

		want := make([]int, len(initial_a))
		copy(want, initial_a)

		initial_a[0] = 12
		initial_a[2] = 4

		assertClocksEqual(t, got.GetClock(), want)

		if reflect.DeepEqual(initial_a, got.GetClock()) {
			t.Errorf("Initial array %v should not be equal to clock %v", initial_a, got.GetClock())
		}

	})

}