gods/stacks/arraystack/arraystack_test.go

476 lines
11 KiB
Go

// Copyright (c) 2015, Emir Pasic. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package arraystack
import (
"encoding/json"
"fmt"
"strings"
"testing"
)
func TestStackPush(t *testing.T) {
stack := New()
if actualValue := stack.Empty(); actualValue != true {
t.Errorf("Got %v expected %v", actualValue, true)
}
stack.Push(1)
stack.Push(2)
stack.Push(3)
if actualValue := stack.Values(); actualValue[0].(int) != 3 || actualValue[1].(int) != 2 || actualValue[2].(int) != 1 {
t.Errorf("Got %v expected %v", actualValue, "[3,2,1]")
}
if actualValue := stack.Empty(); actualValue != false {
t.Errorf("Got %v expected %v", actualValue, false)
}
if actualValue := stack.Size(); actualValue != 3 {
t.Errorf("Got %v expected %v", actualValue, 3)
}
if actualValue, ok := stack.Peek(); actualValue != 3 || !ok {
t.Errorf("Got %v expected %v", actualValue, 3)
}
}
func TestStackPeek(t *testing.T) {
stack := New()
if actualValue, ok := stack.Peek(); actualValue != nil || ok {
t.Errorf("Got %v expected %v", actualValue, nil)
}
stack.Push(1)
stack.Push(2)
stack.Push(3)
if actualValue, ok := stack.Peek(); actualValue != 3 || !ok {
t.Errorf("Got %v expected %v", actualValue, 3)
}
}
func TestStackPop(t *testing.T) {
stack := New()
stack.Push(1)
stack.Push(2)
stack.Push(3)
stack.Pop()
if actualValue, ok := stack.Peek(); actualValue != 2 || !ok {
t.Errorf("Got %v expected %v", actualValue, 2)
}
if actualValue, ok := stack.Pop(); actualValue != 2 || !ok {
t.Errorf("Got %v expected %v", actualValue, 2)
}
if actualValue, ok := stack.Pop(); actualValue != 1 || !ok {
t.Errorf("Got %v expected %v", actualValue, 1)
}
if actualValue, ok := stack.Pop(); actualValue != nil || ok {
t.Errorf("Got %v expected %v", actualValue, nil)
}
if actualValue := stack.Empty(); actualValue != true {
t.Errorf("Got %v expected %v", actualValue, true)
}
if actualValue := stack.Values(); len(actualValue) != 0 {
t.Errorf("Got %v expected %v", actualValue, "[]")
}
}
func TestStackIteratorOnEmpty(t *testing.T) {
stack := New()
it := stack.Iterator()
for it.Next() {
t.Errorf("Shouldn't iterate on empty stack")
}
}
func TestStackIteratorNext(t *testing.T) {
stack := New()
stack.Push("a")
stack.Push("b")
stack.Push("c")
it := stack.Iterator()
count := 0
for it.Next() {
count++
index := it.Index()
value := it.Value()
switch index {
case 0:
if actualValue, expectedValue := value, "c"; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
case 1:
if actualValue, expectedValue := value, "b"; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
case 2:
if actualValue, expectedValue := value, "a"; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
default:
t.Errorf("Too many")
}
if actualValue, expectedValue := index, count-1; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
}
if actualValue, expectedValue := count, 3; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
}
func TestStackIteratorPrev(t *testing.T) {
stack := New()
stack.Push("a")
stack.Push("b")
stack.Push("c")
it := stack.Iterator()
for it.Next() {
}
count := 0
for it.Prev() {
count++
index := it.Index()
value := it.Value()
switch index {
case 0:
if actualValue, expectedValue := value, "c"; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
case 1:
if actualValue, expectedValue := value, "b"; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
case 2:
if actualValue, expectedValue := value, "a"; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
default:
t.Errorf("Too many")
}
if actualValue, expectedValue := index, 3-count; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
}
if actualValue, expectedValue := count, 3; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
}
func TestStackIteratorBegin(t *testing.T) {
stack := New()
it := stack.Iterator()
it.Begin()
stack.Push("a")
stack.Push("b")
stack.Push("c")
for it.Next() {
}
it.Begin()
it.Next()
if index, value := it.Index(), it.Value(); index != 0 || value != "c" {
t.Errorf("Got %v,%v expected %v,%v", index, value, 0, "c")
}
}
func TestStackIteratorEnd(t *testing.T) {
stack := New()
it := stack.Iterator()
if index := it.Index(); index != -1 {
t.Errorf("Got %v expected %v", index, -1)
}
it.End()
if index := it.Index(); index != 0 {
t.Errorf("Got %v expected %v", index, 0)
}
stack.Push("a")
stack.Push("b")
stack.Push("c")
it.End()
if index := it.Index(); index != stack.Size() {
t.Errorf("Got %v expected %v", index, stack.Size())
}
it.Prev()
if index, value := it.Index(), it.Value(); index != stack.Size()-1 || value != "a" {
t.Errorf("Got %v,%v expected %v,%v", index, value, stack.Size()-1, "a")
}
}
func TestStackIteratorFirst(t *testing.T) {
stack := New()
it := stack.Iterator()
if actualValue, expectedValue := it.First(), false; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
stack.Push("a")
stack.Push("b")
stack.Push("c")
if actualValue, expectedValue := it.First(), true; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
if index, value := it.Index(), it.Value(); index != 0 || value != "c" {
t.Errorf("Got %v,%v expected %v,%v", index, value, 0, "c")
}
}
func TestStackIteratorLast(t *testing.T) {
stack := New()
it := stack.Iterator()
if actualValue, expectedValue := it.Last(), false; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
stack.Push("a")
stack.Push("b")
stack.Push("c")
if actualValue, expectedValue := it.Last(), true; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
if index, value := it.Index(), it.Value(); index != 2 || value != "a" {
t.Errorf("Got %v,%v expected %v,%v", index, value, 2, "a")
}
}
func TestStackIteratorNextTo(t *testing.T) {
// Sample seek function, i.e. string starting with "b"
seek := func(index int, value interface{}) bool {
return strings.HasSuffix(value.(string), "b")
}
// NextTo (empty)
{
stack := New()
it := stack.Iterator()
for it.NextTo(seek) {
t.Errorf("Shouldn't iterate on empty stack")
}
}
// NextTo (not found)
{
stack := New()
stack.Push("xx")
stack.Push("yy")
it := stack.Iterator()
for it.NextTo(seek) {
t.Errorf("Shouldn't iterate on empty stack")
}
}
// NextTo (found)
{
stack := New()
stack.Push("aa")
stack.Push("bb")
stack.Push("cc")
it := stack.Iterator()
it.Begin()
if !it.NextTo(seek) {
t.Errorf("Shouldn't iterate on empty stack")
}
if index, value := it.Index(), it.Value(); index != 1 || value.(string) != "bb" {
t.Errorf("Got %v,%v expected %v,%v", index, value, 1, "bb")
}
if !it.Next() {
t.Errorf("Should go to first element")
}
if index, value := it.Index(), it.Value(); index != 2 || value.(string) != "aa" {
t.Errorf("Got %v,%v expected %v,%v", index, value, 2, "aa")
}
if it.Next() {
t.Errorf("Should not go past last element")
}
}
}
func TestStackIteratorPrevTo(t *testing.T) {
// Sample seek function, i.e. string starting with "b"
seek := func(index int, value interface{}) bool {
return strings.HasSuffix(value.(string), "b")
}
// PrevTo (empty)
{
stack := New()
it := stack.Iterator()
it.End()
for it.PrevTo(seek) {
t.Errorf("Shouldn't iterate on empty stack")
}
}
// PrevTo (not found)
{
stack := New()
stack.Push("xx")
stack.Push("yy")
it := stack.Iterator()
it.End()
for it.PrevTo(seek) {
t.Errorf("Shouldn't iterate on empty stack")
}
}
// PrevTo (found)
{
stack := New()
stack.Push("aa")
stack.Push("bb")
stack.Push("cc")
it := stack.Iterator()
it.End()
if !it.PrevTo(seek) {
t.Errorf("Shouldn't iterate on empty stack")
}
if index, value := it.Index(), it.Value(); index != 1 || value.(string) != "bb" {
t.Errorf("Got %v,%v expected %v,%v", index, value, 1, "bb")
}
if !it.Prev() {
t.Errorf("Should go to first element")
}
if index, value := it.Index(), it.Value(); index != 0 || value.(string) != "cc" {
t.Errorf("Got %v,%v expected %v,%v", index, value, 0, "cc")
}
if it.Prev() {
t.Errorf("Should not go before first element")
}
}
}
func TestStackSerialization(t *testing.T) {
stack := New()
stack.Push("a")
stack.Push("b")
stack.Push("c")
var err error
assert := func() {
if actualValue, expectedValue := fmt.Sprintf("%s%s%s", stack.Values()...), "cba"; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
if actualValue, expectedValue := stack.Size(), 3; actualValue != expectedValue {
t.Errorf("Got %v expected %v", actualValue, expectedValue)
}
if err != nil {
t.Errorf("Got error %v", err)
}
}
assert()
bytes, err := stack.ToJSON()
assert()
err = stack.FromJSON(bytes)
assert()
bytes, err = json.Marshal([]interface{}{"a", "b", "c", stack})
if err != nil {
t.Errorf("Got error %v", err)
}
}
func benchmarkPush(b *testing.B, stack *Stack, size int) {
for i := 0; i < b.N; i++ {
for n := 0; n < size; n++ {
stack.Push(n)
}
}
}
func benchmarkPop(b *testing.B, stack *Stack, size int) {
for i := 0; i < b.N; i++ {
for n := 0; n < size; n++ {
stack.Pop()
}
}
}
func BenchmarkArrayStackPop100(b *testing.B) {
b.StopTimer()
size := 100
stack := New()
for n := 0; n < size; n++ {
stack.Push(n)
}
b.StartTimer()
benchmarkPop(b, stack, size)
}
func BenchmarkArrayStackPop1000(b *testing.B) {
b.StopTimer()
size := 1000
stack := New()
for n := 0; n < size; n++ {
stack.Push(n)
}
b.StartTimer()
benchmarkPop(b, stack, size)
}
func BenchmarkArrayStackPop10000(b *testing.B) {
b.StopTimer()
size := 10000
stack := New()
for n := 0; n < size; n++ {
stack.Push(n)
}
b.StartTimer()
benchmarkPop(b, stack, size)
}
func BenchmarkArrayStackPop100000(b *testing.B) {
b.StopTimer()
size := 100000
stack := New()
for n := 0; n < size; n++ {
stack.Push(n)
}
b.StartTimer()
benchmarkPop(b, stack, size)
}
func BenchmarkArrayStackPush100(b *testing.B) {
b.StopTimer()
size := 100
stack := New()
b.StartTimer()
benchmarkPush(b, stack, size)
}
func BenchmarkArrayStackPush1000(b *testing.B) {
b.StopTimer()
size := 1000
stack := New()
for n := 0; n < size; n++ {
stack.Push(n)
}
b.StartTimer()
benchmarkPush(b, stack, size)
}
func BenchmarkArrayStackPush10000(b *testing.B) {
b.StopTimer()
size := 10000
stack := New()
for n := 0; n < size; n++ {
stack.Push(n)
}
b.StartTimer()
benchmarkPush(b, stack, size)
}
func BenchmarkArrayStackPush100000(b *testing.B) {
b.StopTimer()
size := 100000
stack := New()
for n := 0; n < size; n++ {
stack.Push(n)
}
b.StartTimer()
benchmarkPush(b, stack, size)
}