func TestIterate(t *testing.T) {
const N = 1000
deque := deque.New()
for i := 0; i < N; i++ {
deque.PushBack(i)
}
// iterate from front to back
i := 0
for e := deque.Front(); e != nil; e = e.Next() {
if e.Value != i {
t.Errorf("got: %d, want: %d", e.Value, i)
}
i++
}
// iterate from back to front
i = N - 1
for e := deque.Back(); e != nil; e = e.Prev() {
if e.Value != i {
t.Errorf("got: %d, want: %d", e.Value, i)
}
i--
}
}
func TestPushPopRandom(t *testing.T) {
const N = 1000
deque := deque.New()
// randomly push items to the front or to the back
for i := 0; i < N; i++ {
switch rand.Intn(2) {
case 0:
deque.PushFront("f")
case 1:
deque.PushBack("b")
}
}
// randomly pop items from the front or from the back
for i := 0; i < N; i++ {
switch rand.Intn(2) {
case 0:
if deque.PopFront() == nil {
t.Errorf("deque empty!")
}
case 1:
if deque.PopBack() == nil {
t.Errorf("deque empty!")
}
}
}
}
func TestSize(t *testing.T) {
const N = 10
deque := deque.New()
if deque.Size() != 0 {
t.Errorf("got: %d, want: 0", deque.Size())
}
for i := 0; i < N; i++ {
deque.PushFront(i)
}
if deque.Size() != N {
t.Errorf("got: %d, want: %d", deque.Size(), N)
}
for deque.Size() > 0 {
deque.PopFront()
}
if deque.Size() != 0 {
t.Errorf("got: %d, want: 0", deque.Size())
}
for i := 0; i < N; i++ {
deque.PushBack(i)
}
if deque.Size() != N {
t.Errorf("got: %d, want: %d", deque.Size(), N)
}
for deque.Size() > 0 {
deque.PopBack()
}
if deque.Size() != 0 {
t.Errorf("got: %d, want: 0", deque.Size())
}
}
func TestEmpty_PopBack(t *testing.T) {
deque := deque.New()
for i := 0; i < 3; i++ {
back := deque.PopBack()
if back != nil {
t.Errorf("got: %v, want: <nil>", back)
}
}
}
func TestEmpty_PopFront(t *testing.T) {
deque := deque.New()
for i := 0; i < 3; i++ {
front := deque.PopFront()
if front != nil {
t.Errorf("got: %v, want: <nil>", front)
}
}
}
func BenchmarkBackItem(b *testing.B) {
const N = 16
deque := deque.New()
for i := 0; i < N; i++ {
deque.PushBack(i)
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
_ = deque.BackItem()
}
}
func TestClear(t *testing.T) {
const N = 10
deque := deque.New()
for i := 0; i < N; i++ {
deque.PushFront(i)
}
deque.Clear()
if deque.Size() != 0 {
t.Errorf("got: %d, want: 0", deque.Size())
}
}
func TestPushPeek(t *testing.T) {
deque := deque.New()
deque.PushFront("a")
if deque.FrontItem() != "a" {
t.Errorf("got: %v, want: a", deque.FrontItem())
}
deque.PushBack("z")
if deque.BackItem() != "z" {
t.Errorf("got: %v, want: z", deque.BackItem())
}
}
func TestEmpty_item(t *testing.T) {
deque := deque.New()
frontItem := deque.FrontItem()
if frontItem != nil {
t.Errorf("got: %v, want: <nil>", frontItem)
}
backItem := deque.BackItem()
if backItem != nil {
t.Errorf("got: %v, want: <nil>", backItem)
}
}
func TestEmpty_iterator(t *testing.T) {
deque := deque.New()
front := deque.Front()
if front != nil {
t.Errorf("got: %v, want: <nil>", front.Value)
}
back := deque.Back()
if back != nil {
t.Errorf("got: %v, want: <nil>", back.Value)
}
}
func BenchmarkPushPopBack_1000(b *testing.B) {
for i := 0; i < b.N; i++ {
deque := deque.New()
for i := 0; i < 1000; i++ {
deque.PushBack(i)
}
sum := 0
for i := 0; i < 1000; i++ {
sum += deque.PopBack().(int)
}
}
}
func BenchmarkPushPopFront_10(b *testing.B) {
for i := 0; i < b.N; i++ {
deque := deque.New()
for i := 0; i < 10; i++ {
deque.PushFront(i)
}
sum := 0
for i := 0; i < 10; i++ {
sum += deque.PopFront().(int)
}
}
}
func BenchmarkIterate_backward(b *testing.B) {
const N = 1024
deque := deque.New()
for i := 0; i < N; i++ {
deque.PushBack(i)
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
for it := deque.Back(); it != nil; it = it.Prev() {
_ = it.Value
}
}
}
func TestPushPop(t *testing.T) {
deque := deque.New()
deque.PushFront("a")
deque.PushBack("z")
front := deque.PopFront()
if front != "a" {
t.Errorf("got: %v, want: a", front)
}
back := deque.PopBack()
if back != "z" {
t.Errorf("got: %v, want: z", back)
}
}
func ExampleIterator() {
const N = 10
deque := deque.New()
for i := 0; i < N; i++ {
deque.PushBack(i)
}
// iterate from front to back
for it := deque.Front(); it != nil; it = it.Next() {
fmt.Printf("%v", it.Value)
}
fmt.Println()
// iterate from back to front
for it := deque.Back(); it != nil; it = it.Prev() {
fmt.Printf("%v", it.Value)
}
fmt.Println()
// Output:
// 0123456789
// 9876543210
}