// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package list
import "testing"
func checkListLen(t *testing.T, l *List, len int) bool {
if n := l.Len(); n != len {
t.Errorf("l.Len() = %d, want %d", n, len)
return false
}
return true
}
func checkListPointers(t *testing.T, l *List, es []*Element) {
root := &l.root
if !checkListLen(t, l, len(es)) {
return
}
// zero length lists must be the zero value or properly initialized (sentinel circle)
if len(es) == 0 {
if l.root.next != nil && l.root.next != root || l.root.prev != nil && l.root.prev != root {
t.Errorf("l.root.next = %p, l.root.prev = %p; both should both be nil or %p", l.root.next, l.root.prev, root)
}
return
}
// len(es) > 0
// check internal and external prev/next connections
for i, e := range es {
prev := root
Prev := (*Element)(nil)
if i > 0 {
prev = es[i-1]
Prev = prev
}
if p := e.prev; p != prev {
t.Errorf("elt[%d](%p).prev = %p, want %p", i, e, p, prev)
}
if p := e.Prev(); p != Prev {
t.Errorf("elt[%d](%p).Prev() = %p, want %p", i, e, p, Prev)
}
next := root
Next := (*Element)(nil)
if i < len(es)-1 {
next = es[i+1]
Next = next
}
if n := e.next; n != next {
t.Errorf("elt[%d](%p).next = %p, want %p", i, e, n, next)
}
if n := e.Next(); n != Next {
t.Errorf("elt[%d](%p).Next() = %p, want %p", i, e, n, Next)
}
}
}
func TestList(t *testing.T) {
l := New()
checkListPointers(t, l, []*Element{})
// Single element list
e := l.PushFront("a")
checkListPointers(t, l, []*Element{e})
l.MoveToFront(e)
checkListPointers(t, l, []*Element{e})
l.MoveToBack(e)
checkListPointers(t, l, []*Element{e})
l.Remove(e)
checkListPointers(t, l, []*Element{})
// Bigger list
e2 := l.PushFront(2)
e1 := l.PushFront(1)
e3 := l.PushBack(3)
e4 := l.PushBack("banana")
checkListPointers(t, l, []*Element{e1, e2, e3, e4})
l.Remove(e2)
checkListPointers(t, l, []*Element{e1, e3, e4})
l.MoveToFront(e3) // move from middle
checkListPointers(t, l, []*Element{e3, e1, e4})
l.MoveToFront(e1)
l.MoveToBack(e3) // move from middle
checkListPointers(t, l, []*Element{e1, e4, e3})
l.MoveToFront(e3) // move from back
checkListPointers(t, l, []*Element{e3, e1, e4})
l.MoveToFront(e3) // should be no-op
checkListPointers(t, l, []*Element{e3, e1, e4})
l.MoveToBack(e3) // move from front
checkListPointers(t, l, []*Element{e1, e4, e3})
l.MoveToBack(e3) // should be no-op
checkListPointers(t, l, []*Element{e1, e4, e3})
e2 = l.InsertBefore(2, e1) // insert before front
checkListPointers(t, l, []*Element{e2, e1, e4, e3})
l.Remove(e2)
e2 = l.InsertBefore(2, e4) // insert before middle
checkListPointers(t, l, []*Element{e1, e2, e4, e3})
l.Remove(e2)
e2 = l.InsertBefore(2, e3) // insert before back
checkListPointers(t, l, []*Element{e1, e4, e2, e3})
l.Remove(e2)
e2 = l.InsertAfter(2, e1) // insert after front
checkListPointers(t, l, []*Element{e1, e2, e4, e3})
l.Remove(e2)
e2 = l.InsertAfter(2, e4) // insert after middle
checkListPointers(t, l, []*Element{e1, e4, e2, e3})
l.Remove(e2)
e2 = l.InsertAfter(2, e3) // insert after back
checkListPointers(t, l, []*Element{e1, e4, e3, e2})
l.Remove(e2)
// Check standard iteration.
sum := 0
for e := l.Front(); e != nil; e = e.Next() {
if i, ok := e.Value.(int); ok {
sum += i
}
}
if sum != 4 {
t.Errorf("sum over l = %d, want 4", sum)
}
// Clear all elements by iterating
var next *Element
for e := l.Front(); e != nil; e = next {
next = e.Next()
l.Remove(e)
}
checkListPointers(t, l, []*Element{})
}
func checkList(t *testing.T, l *List, es []interface{}) {
if !checkListLen(t, l, len(es)) {
return
}
i := 0
for e := l.Front(); e != nil; e = e.Next() {
le := e.Value.(int)
if le != es[i] {
t.Errorf("elt[%d].Value = %v, want %v", i, le, es[i])
}
i++
}
}
func TestExtending(t *testing.T) {
l1 := New()
l2 := New()
l1.PushBack(1)
l1.PushBack(2)
l1.PushBack(3)
l2.PushBack(4)
l2.PushBack(5)
l3 := New()
l3.PushBackList(l1)
checkList(t, l3, []interface{}{1, 2, 3})
l3.PushBackList(l2)
checkList(t, l3, []interface{}{1, 2, 3, 4, 5})
l3 = New()
l3.PushFrontList(l2)
checkList(t, l3, []interface{}{4, 5})
l3.PushFrontList(l1)
checkList(t, l3, []interface{}{1, 2, 3, 4, 5})
checkList(t, l1, []interface{}{1, 2, 3})
checkList(t, l2, []interface{}{4, 5})
l3 = New()
l3.PushBackList(l1)
checkList(t, l3, []interface{}{1, 2, 3})
l3.PushBackList(l3)
checkList(t, l3, []interface{}{1, 2, 3, 1, 2, 3})
l3 = New()
l3.PushFrontList(l1)
checkList(t, l3, []interface{}{1, 2, 3})
l3.PushFrontList(l3)
checkList(t, l3, []interface{}{1, 2, 3, 1, 2, 3})
l3 = New()
l1.PushBackList(l3)
checkList(t, l1, []interface{}{1, 2, 3})
l1.PushFrontList(l3)
checkList(t, l1, []interface{}{1, 2, 3})
}
func TestRemove(t *testing.T) {
l := New()
e1 := l.PushBack(1)
e2 := l.PushBack(2)
checkListPointers(t, l, []*Element{e1, e2})
e := l.Front()
l.Remove(e)
checkListPointers(t, l, []*Element{e2})
l.Remove(e)
checkListPointers(t, l, []*Element{e2})
}
func TestIssue4103(t *testing.T) {
l1 := New()
l1.PushBack(1)
l1.PushBack(2)
l2 := New()
l2.PushBack(3)
l2.PushBack(4)
e := l1.Front()
l2.Remove(e) // l2 should not change because e is not an element of l2
if n := l2.Len(); n != 2 {
t.Errorf("l2.Len() = %d, want 2", n)
}
l1.InsertBefore(8, e)
if n := l1.Len(); n != 3 {
t.Errorf("l1.Len() = %d, want 3", n)
}
}
func TestIssue6349(t *testing.T) {
l := New()
l.PushBack(1)
l.PushBack(2)
e := l.Front()
l.Remove(e)
if e.Value != 1 {
t.Errorf("e.value = %d, want 1", e.Value)
}
if e.Next() != nil {
t.Errorf("e.Next() != nil")
}
if e.Prev() != nil {
t.Errorf("e.Prev() != nil")
}
}
func TestMove(t *testing.T) {
l := New()
e1 := l.PushBack(1)
e2 := l.PushBack(2)
e3 := l.PushBack(3)
e4 := l.PushBack(4)
l.MoveAfter(e3, e3)
checkListPointers(t, l, []*Element{e1, e2, e3, e4})
l.MoveBefore(e2, e2)
checkListPointers(t, l, []*Element{e1, e2, e3, e4})
l.MoveAfter(e3, e2)
checkListPointers(t, l, []*Element{e1, e2, e3, e4})
l.MoveBefore(e2, e3)
checkListPointers(t, l, []*Element{e1, e2, e3, e4})
l.MoveBefore(e2, e4)
checkListPointers(t, l, []*Element{e1, e3, e2, e4})
e1, e2, e3, e4 = e1, e3, e2, e4
l.MoveBefore(e4, e1)
checkListPointers(t, l, []*Element{e4, e1, e2, e3})
e1, e2, e3, e4 = e4, e1, e2, e3
l.MoveAfter(e4, e1)
checkListPointers(t, l, []*Element{e1, e4, e2, e3})
e1, e2, e3, e4 = e1, e4, e2, e3
l.MoveAfter(e2, e3)
checkListPointers(t, l, []*Element{e1, e3, e2, e4})
e1, e2, e3, e4 = e1, e3, e2, e4
}
// Test PushFront, PushBack, PushFrontList, PushBackList with uninitialized List
func TestZeroList(t *testing.T) {
var l1 = new(List)
l1.PushFront(1)
checkList(t, l1, []interface{}{1})
var l2 = new(List)
l2.PushBack(1)
checkList(t, l2, []interface{}{1})
var l3 = new(List)
l3.PushFrontList(l1)
checkList(t, l3, []interface{}{1})
var l4 = new(List)
l4.PushBackList(l2)
checkList(t, l4, []interface{}{1})
}
// Test that a list l is not modified when calling InsertBefore with a mark that is not an element of l.
func TestInsertBeforeUnknownMark(t *testing.T) {
var l List
l.PushBack(1)
l.PushBack(2)
l.PushBack(3)
l.InsertBefore(1, new(Element))
checkList(t, &l, []interface{}{1, 2, 3})
}
// Test that a list l is not modified when calling InsertAfter with a mark that is not an element of l.
func TestInsertAfterUnknownMark(t *testing.T) {
var l List
l.PushBack(1)
l.PushBack(2)
l.PushBack(3)
l.InsertAfter(1, new(Element))
checkList(t, &l, []interface{}{1, 2, 3})
}
// Test that a list l is not modified when calling MoveAfter or MoveBefore with a mark that is not an element of l.
func TestMoveUnkownMark(t *testing.T) {
var l1 List
e1 := l1.PushBack(1)
var l2 List
e2 := l2.PushBack(2)
l1.MoveAfter(e1, e2)
checkList(t, &l1, []interface{}{1})
checkList(t, &l2, []interface{}{2})
l1.MoveBefore(e1, e2)
checkList(t, &l1, []interface{}{1})
checkList(t, &l2, []interface{}{2})
}