Add new feature in collection framework:

- Implemented slice data structure
- Defined new interfaces Collection, List and Set

Makefile

@@ -12,3 +12,6 @@ dep:
 
 vet:
 	go vet
+
+build:
+	go build -o ./build

pkg/collection/collection.go

@@ -0,0 +1,36 @@
+package collection
+
+type Iterator[E any] interface {
+	HasNext() bool
+	Next() E
+	NextWithIndex() (int, E)
+}
+
+type Iterable[E any] interface {
+	Iterator() Iterator[E]
+}
+
+type Collection[E any] interface {
+	Iterable[E]
+	Empty() bool
+	Size() int
+	Push(item E)
+	Contains(item E) bool
+	Delete(item E) error
+}
+
+type List[E any] interface {
+	Collection[E]
+	Back() (E, error)
+	Front() (E, error)
+	PushBack(item E)
+	PushFront(item E)
+	Index(item E) (int, error)
+	GetAt(pos int) (E, error)
+	PushAt(item E, pos int)
+	DeleteAt(pos int) error
+}
+
+type Set[E comparable] interface {
+	Collection[E]
+}

pkg/collection/errors.go

@@ -0,0 +1,26 @@
+package collection
+
+import "fmt"
+
+var (
+	ErrPositionNegative = fmt.Errorf("position can not be negative")
+	ErrEmptyCollection  = fmt.Errorf("this collection is empty")
+	ErrNodeNotFound     = fmt.Errorf("node not found")
+)
+
+type ErrIndexOutOfBound struct {
+	index int
+	size  int
+}
+
+func (e ErrIndexOutOfBound) Error() string {
+	return fmt.Sprintf("index %d out of bound from range %d and %d", e.index, 0, e.size-1)
+}
+
+type ErrItemNotFound struct {
+	item any
+}
+
+func (e ErrItemNotFound) Error() string {
+	return fmt.Sprintf("item %v not found", e.item)
+}

pkg/collection/iterator.go

@@ -1,11 +0,0 @@
-package collection
-
-type Iterator[E any] interface {
-	HasNext() bool
-	Next() E
-	NextWithIndex() (int, E)
-}
-
-type Iterable[E any] interface {
-	Iterator() Iterator[E]
-}

pkg/collection/linked_list.go

@@ -2,25 +2,10 @@ package collection
 
 import (
 	"fmt"
-	"log"
+	"reflect"
 	"strings"
 )
 
-var (
-	ErrPositionNegative = fmt.Errorf("position can not be negative")
-	ErrEmptyList        = fmt.Errorf("no nodes in list")
-	ErrNodeNotFound     = fmt.Errorf("node not found")
-)
-
-type ErrIndexOutOfBound struct {
-	index int
-	size  int
-}
-
-func (e ErrIndexOutOfBound) Error() string {
-	return fmt.Sprintf("index %d out of bound from range %d and %d", e.index, 0, e.size-1)
-}
-
 type node[E any] struct {
 	value E
 	prev  *node[E]
@@ -112,7 +97,7 @@ func (l *LinkedList[E]) GetAt(pos int) (E, error) {
 // findNode returns node at given position from linked list
 func (l *LinkedList[E]) findNode(pos int) (*node[E], error) {
 	if l.Empty() {
-		return nil, ErrEmptyList
+		return nil, ErrEmptyCollection
 	}
 
 	ptr := l.head
@@ -131,6 +116,30 @@ func (l *LinkedList[E]) findNode(pos int) (*node[E], error) {
 	return ptr, nil
 }
 
+func (l *LinkedList[E]) Contains(item E) bool {
+	for it := l.Iterator(); it.HasNext(); {
+		x := it.Next()
+		if reflect.DeepEqual(item, x) {
+			return true
+		}
+	}
+	return false
+}
+
+func (l *LinkedList[E]) Index(item E) (int, error) {
+	for it := l.Iterator(); it.HasNext(); {
+		i, x := it.NextWithIndex()
+		if reflect.DeepEqual(item, x) {
+			return i, nil
+		}
+	}
+	return 0, ErrItemNotFound{item}
+}
+
+func (l *LinkedList[E]) Push(item E) {
+	l.PushBack(item)
+}
+
 func (l *LinkedList[E]) PushFront(item E) {
 	l.PushAt(item, 0)
 }
@@ -175,17 +184,23 @@ func (l *LinkedList[E]) PushAt(item E, pos int) {
 	l.size++
 }
 
+func (l *LinkedList[E]) Delete(item E) error {
+	pos, err := l.Index(item)
+	if err != nil {
+		return err
+	}
+	return l.DeleteAt(pos)
+}
+
 // DeleteAt deletes node at given position from linked list
 func (l *LinkedList[E]) DeleteAt(pos int) error {
 	// validate the position
 	if pos < 0 {
-		log.Println("position can not be negative")
 		return ErrPositionNegative
 	}
 
 	if l.size == 0 {
-		log.Println("no nodes in list")
-		return ErrEmptyList
+		return ErrEmptyCollection
 	}
 
 	if pos == 0 {
@@ -199,7 +214,6 @@ func (l *LinkedList[E]) DeleteAt(pos int) error {
 	} else {
 		prevNode, _ := l.findNode(pos - 1)
 		if prevNode == nil {
-			log.Println("node not found")
 			return ErrNodeNotFound
 		}
 		myNode, err := l.findNode(pos)

pkg/collection/linked_list_test.go

@@ -54,14 +54,14 @@ func TestLinkedList_GetAt(t *testing.T) {
 		{description: "get middle item", list: NewLinkedList(1, 2, 3), pos: 1, want: 2, err: nil},
 		{description: "get last item", list: NewLinkedList(1, 2, 3), pos: 2, want: 3, err: nil},
 		{description: "get last item", list: NewLinkedList(1, 2, 3), pos: 2, want: 3, err: nil},
-		{description: "no items in list return zero value of the type", list: NewLinkedList[int](), pos: 0, want: 0, err: ErrEmptyList},
+		{description: "no items in list return zero value of the type", list: NewLinkedList[int](), pos: 0, want: 0, err: ErrEmptyCollection},
 		{description: "get item with negative position", list: NewLinkedList(1, 2, 3), pos: -1, want: 0, err: ErrPositionNegative},
 		{description: "get item with index out of bound", list: NewLinkedList(1, 2, 3), pos: 4, want: 0, err: ErrIndexOutOfBound{4, 3}},
 	}
 
 	for _, tt := range useCases {
 		result, err := tt.list.GetAt(tt.pos)
-		if result != tt.want && err != tt.err {
+		if result != tt.want || err != tt.err {
 			t.Errorf("test: %s want %v got %v", tt.description, tt.want, result)
 		}
 	}
@@ -74,14 +74,14 @@ func TestLinkedList_Back(t *testing.T) {
 		err         error
 		want        int
 	}{
-		{description: "no items in list return zero value of the type", list: NewLinkedList[int](), want: 0, err: ErrEmptyList},
+		{description: "no items in list return zero value of the type", list: NewLinkedList[int](), want: 0, err: ErrEmptyCollection},
 		{description: "singleton list return first element", list: NewLinkedList(1), want: 1},
 		{description: "get last item", list: NewLinkedList(1, 2, 3), want: 3},
 	}
 
 	for _, tt := range useCases {
 		result, err := tt.list.Back()
-		if result != tt.want && err != tt.err {
+		if result != tt.want || err != tt.err {
 			t.Errorf("test: %s want %v got %v", tt.description, tt.want, result)
 		}
 	}
@@ -94,19 +94,44 @@ func TestLinkedList_Front(t *testing.T) {
 		err         error
 		want        int
 	}{
-		{description: "no items in list return zero value of the type", list: NewLinkedList[int](), want: 0, err: ErrEmptyList},
+		{description: "no items in list return zero value of the type", list: NewLinkedList[int](), want: 0, err: ErrEmptyCollection},
 		{description: "singleton list return first element", list: NewLinkedList(1), want: 1},
 		{description: "get first item", list: NewLinkedList(1, 2, 3), want: 1},
 	}
 
 	for _, tt := range useCases {
 		result, err := tt.list.Front()
-		if result != tt.want && err != tt.err {
+		if result != tt.want || err != tt.err {
 			t.Errorf("test: %s want %v got %v", tt.description, tt.want, result)
 		}
 	}
 }
 
+func TestLinkedList_Push(t *testing.T) {
+	useCases := []struct {
+		description string
+		original    *LinkedList[int]
+		modified    *LinkedList[int]
+		item        int
+	}{
+		{description: "push item in empty slice",
+			original: NewLinkedList[int](),
+			modified: NewLinkedList(1),
+			item:     1},
+		{description: "push item in slice with item in last position",
+			original: NewLinkedList(1, 2),
+			modified: NewLinkedList(1, 2, 3),
+			item:     3},
+	}
+
+	for _, tt := range useCases {
+		tt.original.Push(tt.item)
+		if !compareLists(tt.original, tt.modified) {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.modified, tt.original)
+		}
+	}
+}
+
 func TestLinkedList_PushAt(t *testing.T) {
 	useCases := []struct {
 		description string
@@ -205,6 +230,41 @@ func TestLinkedList_PushFront(t *testing.T) {
 	}
 }
 
+func TestLinkedList_Delete(t *testing.T) {
+	useCases := []struct {
+		description string
+		original    *LinkedList[int]
+		modified    *LinkedList[int]
+		item        int
+		err         error
+	}{
+		{description: "delete item in empty list",
+			original: NewLinkedList[int](),
+			modified: NewLinkedList[int](),
+			item:     0,
+			err:      ErrItemNotFound{0}},
+		{description: "delete item in list with item in first position",
+			original: NewLinkedList(1, 2, 3),
+			modified: NewLinkedList(2, 3),
+			item:     1},
+		{description: "delete item in list with item in middle position",
+			original: NewLinkedList(1, 2, 3),
+			modified: NewLinkedList(1, 3),
+			item:     2},
+		{description: "delete item in list with item in last position",
+			original: NewLinkedList(1, 2, 3),
+			modified: NewLinkedList(1, 2),
+			item:     3},
+	}
+
+	for _, tt := range useCases {
+		err := tt.original.Delete(tt.item)
+		if !compareLists(tt.original, tt.modified) || err != tt.err {
+			t.Errorf("test: %s want {%v, %v} got {%v, %v}", tt.description, tt.modified, tt.err, tt.original, err)
+		}
+	}
+}
+
 func TestLinkedList_DeleteAt(t *testing.T) {
 	useCases := []struct {
 		description string
@@ -215,17 +275,17 @@ func TestLinkedList_DeleteAt(t *testing.T) {
 	}{
 		{description: "delete item with negative position",
 			original: NewLinkedList[int](),
-			modified: nil,
+			modified: NewLinkedList[int](),
 			pos:      -1,
 			err:      ErrPositionNegative},
 		{description: "delete item in empty list",
 			original: NewLinkedList[int](),
-			modified: nil,
+			modified: NewLinkedList[int](),
 			pos:      0,
-			err:      ErrEmptyList},
+			err:      ErrEmptyCollection},
 		{description: "delete item in position not found",
 			original: NewLinkedList(1, 2, 3),
-			modified: NewLinkedList[int](),
+			modified: NewLinkedList(1, 2, 3),
 			pos:      5,
 			err:      ErrNodeNotFound},
 		{description: "delete item in first position",
@@ -247,8 +307,49 @@ func TestLinkedList_DeleteAt(t *testing.T) {
 
 	for _, tt := range useCases {
 		err := tt.original.DeleteAt(tt.pos)
-		if !compareLists(tt.original, tt.modified) && err != tt.err {
-			t.Errorf("test: %s want %v got %v", tt.description, tt.modified, tt.original)
+		if !compareLists(tt.original, tt.modified) || err != tt.err {
+			t.Errorf("test: %s want {%v, %v} got {%v, %v}", tt.description, tt.modified, tt.err, tt.original, err)
+		}
+	}
+}
+
+func TestLinkedList_Contains(t *testing.T) {
+	useCases := []struct {
+		description string
+		list        *LinkedList[int]
+		item        int
+		want        bool
+	}{
+		{description: "empty linked list contain item", list: NewLinkedList[int](), item: 0, want: false},
+		{description: "linked list with items search item no found", list: NewLinkedList[int](1, 2, 3), item: 0, want: false},
+		{description: "linked list with items search item found", list: NewLinkedList[int](1, 2, 3), item: 3, want: true},
+	}
+
+	for _, tt := range useCases {
+		result := tt.list.Contains(tt.item)
+		if result != tt.want {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.want, result)
+		}
+	}
+}
+
+func TestLinkedList_Index(t *testing.T) {
+	useCases := []struct {
+		description string
+		list        *LinkedList[int]
+		item        int
+		pos         int
+		err         error
+	}{
+		{description: "empty linked list contain item", list: NewLinkedList[int](), item: 0, pos: 0, err: ErrItemNotFound{0}},
+		{description: "linked list with items search item no found", list: NewLinkedList[int](1, 2, 3), item: 0, pos: 0, err: ErrItemNotFound{0}},
+		{description: "linked list with items search item found", list: NewLinkedList[int](1, 2, 3), item: 3, pos: 2, err: nil},
+	}
+
+	for _, tt := range useCases {
+		pos, err := tt.list.Index(tt.item)
+		if pos != tt.pos || err != tt.err {
+			t.Errorf("test: %s want {%v, %v} got {%v, %v}", tt.description, tt.pos, tt.err, pos, err)
 		}
 	}
 }

pkg/collection/slice.go

@@ -0,0 +1,176 @@
+package collection
+
+import (
+	"fmt"
+	"math"
+	"reflect"
+	"strings"
+)
+
+type sliceIterator[E any] struct {
+	index int
+	slice []E
+}
+
+func (it *sliceIterator[E]) HasNext() bool {
+	return it.index < len(it.slice)
+}
+
+func (it *sliceIterator[E]) Next() E {
+	item := it.slice[it.index]
+	it.index += 1
+	return item
+}
+
+func (it *sliceIterator[E]) NextWithIndex() (int, E) {
+	index := it.index
+	item := it.slice[index]
+	it.index += 1
+	return index, item
+}
+
+type Slice[E any] struct {
+	inner []E
+}
+
+func NewSlice[E any](items ...E) *Slice[E] {
+	return &Slice[E]{items}
+}
+
+func (s *Slice[E]) Iterator() Iterator[E] {
+	if s.Empty() {
+		return &emptyListIterator[E]{}
+	}
+	return &sliceIterator[E]{0, s.inner}
+}
+
+func (s *Slice[E]) Empty() bool {
+	return s.Size() == 0
+}
+
+func (s *Slice[E]) Size() int {
+	return len(s.inner)
+}
+
+func (s *Slice[E]) Back() (E, error) {
+	return s.GetAt(s.Size() - 1)
+}
+
+func (s *Slice[E]) Front() (E, error) {
+	return s.GetAt(0)
+}
+
+func (s *Slice[E]) GetAt(pos int) (E, error) {
+	if s.Empty() {
+		return *new(E), ErrEmptyCollection
+	}
+	if pos < 0 {
+		return *new(E), ErrPositionNegative
+	}
+	if pos < 0 || pos >= s.Size() {
+		return *new(E), ErrIndexOutOfBound{pos, s.Size()}
+	}
+	return s.inner[pos], nil
+}
+
+func (s *Slice[E]) Push(item E) {
+	s.PushBack(item)
+}
+
+func (s *Slice[E]) PushBack(item E) {
+	pos := int(math.Max(0.0, float64(s.Size())))
+	s.PushAt(item, pos)
+}
+
+func (s *Slice[E]) PushFront(item E) {
+	s.PushAt(item, 0)
+}
+
+func (s *Slice[E]) PushAt(item E, pos int) {
+	s.inner = insert(s.inner, item, pos)
+}
+
+func insert[E any](slice []E, item E, pos int) []E {
+	// found https://stackoverflow.com/questions/46128016/insert-a-value-in-a-slice-at-a-given-index
+	n := len(slice)
+	if pos < 0 {
+		pos = (pos%n + n) % n
+	}
+	switch {
+	case pos == n: // nil or empty slice or after last element
+		return append(slice, item)
+
+	case pos < n: // pos < len(slice)
+		slice = append(slice[:pos+1], slice[pos:]...)
+		slice[pos] = item
+		return slice
+
+	case pos < cap(slice): // pos > len(slice)
+		slice = slice[:pos+1]
+		var zero E
+		for i := n; i < pos; i++ {
+			slice[i] = zero
+		}
+		slice[pos] = item
+		return slice
+
+	default:
+		b := make([]E, pos+1) // malloc
+		if n > 0 {
+			copy(b, slice)
+		}
+		b[pos] = item
+		return b
+	}
+}
+
+func (s *Slice[E]) Delete(item E) error {
+	pos, err := s.Index(item)
+	if err != nil {
+		return err
+	}
+	return s.DeleteAt(pos)
+}
+
+func (s *Slice[E]) DeleteAt(pos int) error {
+	if s.Empty() {
+		return ErrEmptyCollection
+	}
+	s.inner = append(s.inner[:pos], s.inner[pos+1:]...)
+	return nil
+}
+
+func (s *Slice[E]) Contains(item E) bool {
+	for _, elem := range s.inner {
+		if reflect.DeepEqual(elem, item) {
+			return true
+		}
+	}
+	return false
+}
+
+func (s *Slice[E]) Index(item E) (int, error) {
+	for i, x := range s.inner {
+		if reflect.DeepEqual(x, item) {
+			return i, nil
+		}
+	}
+	return 0, ErrItemNotFound{item}
+}
+
+func (s *Slice[E]) String() string {
+	var sb strings.Builder
+	sb.WriteString("[")
+	for i := 0; i < s.Size(); i++ {
+		var str string
+		item, _ := s.GetAt(i)
+		if i >= s.Size()-1 {
+			str = fmt.Sprintf("%v", item)
+		} else {
+			str = fmt.Sprintf("%v, ", item)
+		}
+		sb.WriteString(str)
+	}
+	sb.WriteString("]")
+	return sb.String()
+}

pkg/collection/slice_test.go

@@ -0,0 +1,330 @@
+package collection
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestSlice_Empty(t *testing.T) {
+	useCases := []struct {
+		description string
+		slice       *Slice[int]
+		want        bool
+	}{
+		{description: "empty slice", slice: NewSlice[int](), want: true},
+		{description: "full slice", slice: NewSlice[int](1, 2, 3), want: false},
+	}
+
+	for _, tt := range useCases {
+		result := tt.slice.Empty()
+		if result != tt.want {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.want, result)
+		}
+	}
+}
+
+func TestSlice_Size(t *testing.T) {
+	useCases := []struct {
+		description string
+		slice       *Slice[int]
+		want        int
+	}{
+		{description: "empty slice", slice: NewSlice[int](), want: 0},
+		{description: "full slice", slice: NewSlice[int](1, 2, 3), want: 3},
+	}
+
+	for _, tt := range useCases {
+		result := tt.slice.Size()
+		if result != tt.want {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.want, result)
+		}
+	}
+}
+
+func TestSlice_GetAt(t *testing.T) {
+	useCases := []struct {
+		description string
+		slice       *Slice[int]
+		pos         int
+		item        int
+		err         error
+	}{
+		{description: "get item on empty slice", slice: NewSlice[int](), pos: 0, item: 0, err: ErrEmptyCollection},
+		{description: "get item on full slice with out of bound index", slice: NewSlice[int](1, 2, 3), pos: 5, item: 0, err: ErrIndexOutOfBound{5, 3}},
+		{description: "get item on full slice with negative index", slice: NewSlice[int](1, 2, 3), pos: -1, item: 0, err: ErrPositionNegative},
+		{description: "get item on full slice in first position", slice: NewSlice[int](1, 2, 3), pos: 0, item: 1, err: nil},
+		{description: "get item on full slice in middle position", slice: NewSlice[int](1, 2, 3), pos: 1, item: 2, err: nil},
+		{description: "get item on full slice in last position", slice: NewSlice[int](1, 2, 3), pos: 2, item: 3, err: nil},
+	}
+
+	for _, tt := range useCases {
+		result, err := tt.slice.GetAt(tt.pos)
+		if result != tt.item || err != tt.err {
+			t.Errorf("test: %s want {%v, %v} got {%v, %v}", tt.description, tt.item, tt.err, result, err)
+		}
+	}
+}
+
+func TestSlice_Back(t *testing.T) {
+	useCases := []struct {
+		description string
+		slice       *Slice[int]
+		pos         int
+		item        int
+		err         error
+	}{
+		{description: "get item on empty slice", slice: NewSlice[int](), pos: 0, item: 0, err: ErrEmptyCollection},
+		{description: "get item on full slice in last position", slice: NewSlice[int](1, 2, 3), pos: 2, item: 3, err: nil},
+	}
+
+	for _, tt := range useCases {
+		result, err := tt.slice.Back()
+		if result != tt.item || err != tt.err {
+			t.Errorf("test: %s want {%v, %v} got {%v, %v}", tt.description, tt.item, tt.err, result, err)
+		}
+	}
+}
+
+func TestSlice_Front(t *testing.T) {
+	useCases := []struct {
+		description string
+		slice       *Slice[int]
+		pos         int
+		item        int
+		err         error
+	}{
+		{description: "get item on empty slice", slice: NewSlice[int](), pos: 0, item: 0, err: ErrEmptyCollection},
+		{description: "get item on full slice in first position", slice: NewSlice[int](1, 2, 3), pos: 2, item: 1, err: nil},
+	}
+
+	for _, tt := range useCases {
+		result, err := tt.slice.Front()
+		if result != tt.item || err != tt.err {
+			t.Errorf("test: %s want {%v, %v} got {%v, %v}", tt.description, tt.item, tt.err, result, err)
+		}
+	}
+}
+
+func TestSlice_PushAt(t *testing.T) {
+	useCases := []struct {
+		description string
+		original    *Slice[int]
+		modified    *Slice[int]
+		item        int
+		pos         int
+	}{
+		{description: "push item in empty slice",
+			original: NewSlice[int](),
+			modified: NewSlice(1),
+			item:     1,
+			pos:      0},
+		{description: "push item in slice with item in first position",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(0, 1, 2, 3),
+			item:     0,
+			pos:      0},
+		{description: "push item in slice with item in middle position",
+			original: NewSlice(1, 3),
+			modified: NewSlice(1, 2, 3),
+			item:     2,
+			pos:      1},
+		{description: "push item in slice with item in last position",
+			original: NewSlice(1, 2),
+			modified: NewSlice(1, 2, 3),
+			item:     3,
+			pos:      2},
+	}
+
+	for _, tt := range useCases {
+		tt.original.PushAt(tt.item, tt.pos)
+		if !reflect.DeepEqual(tt.original.inner, tt.modified.inner) {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.modified, tt.original)
+		}
+	}
+}
+
+func TestSlice_Push(t *testing.T) {
+	useCases := []struct {
+		description string
+		original    *Slice[int]
+		modified    *Slice[int]
+		item        int
+	}{
+		{description: "push item in empty slice",
+			original: NewSlice[int](),
+			modified: NewSlice(1),
+			item:     1},
+		{description: "push item in slice with item in last position",
+			original: NewSlice(1, 2),
+			modified: NewSlice(1, 2, 3),
+			item:     3},
+	}
+
+	for _, tt := range useCases {
+		tt.original.Push(tt.item)
+		if !reflect.DeepEqual(tt.original.inner, tt.modified.inner) {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.modified, tt.original)
+		}
+	}
+}
+
+func TestSlice_PushBack(t *testing.T) {
+	useCases := []struct {
+		description string
+		original    *Slice[int]
+		modified    *Slice[int]
+		item        int
+	}{
+		{description: "push item in empty slice",
+			original: NewSlice[int](),
+			modified: NewSlice(1),
+			item:     1},
+		{description: "push item in slice with item in last position",
+			original: NewSlice(1, 2),
+			modified: NewSlice(1, 2, 3),
+			item:     3},
+	}
+
+	for _, tt := range useCases {
+		tt.original.PushBack(tt.item)
+		if !reflect.DeepEqual(tt.original.inner, tt.modified.inner) {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.modified, tt.original)
+		}
+	}
+}
+
+func TestSlice_PushFront(t *testing.T) {
+	useCases := []struct {
+		description string
+		original    *Slice[int]
+		modified    *Slice[int]
+		item        int
+	}{
+		{description: "push item in empty slice",
+			original: NewSlice[int](),
+			modified: NewSlice(1),
+			item:     1},
+		{description: "push item in slice with item in first position",
+			original: NewSlice(2, 3),
+			modified: NewSlice(1, 2, 3),
+			item:     1},
+	}
+
+	for _, tt := range useCases {
+		tt.original.PushFront(tt.item)
+		if !reflect.DeepEqual(tt.original.inner, tt.modified.inner) {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.modified, tt.original)
+		}
+	}
+}
+
+func TestSlice_Delete(t *testing.T) {
+	useCases := []struct {
+		description string
+		original    *Slice[int]
+		modified    *Slice[int]
+		item        int
+		err         error
+	}{
+		{description: "delete item in empty slice",
+			original: NewSlice[int](),
+			modified: NewSlice[int](),
+			item:     0,
+			err:      ErrItemNotFound{0}},
+		{description: "delete item in slice with item in first position",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(2, 3),
+			item:     1},
+		{description: "delete item in slice with item in middle position",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(1, 3),
+			item:     2},
+		{description: "delete item in slice with item in last position",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(1, 2),
+			item:     3},
+	}
+
+	for _, tt := range useCases {
+		err := tt.original.Delete(tt.item)
+		if !reflect.DeepEqual(tt.original.inner, tt.modified.inner) || err != tt.err {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.modified, tt.original)
+		}
+	}
+}
+
+func TestSlice_DeleteAt(t *testing.T) {
+	useCases := []struct {
+		description string
+		original    *Slice[int]
+		modified    *Slice[int]
+		pos         int
+		err         error
+	}{
+		{description: "delete item in empty slice",
+			original: NewSlice[int](),
+			modified: NewSlice[int](),
+			pos:      0,
+			err:      ErrEmptyCollection},
+		{description: "delete item in slice with item in first position",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(2, 3),
+			pos:      0},
+		{description: "delete item in slice with item in middle position",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(1, 3),
+			pos:      1},
+		{description: "delete item in slice with item in last position",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(1, 2),
+			pos:      2},
+	}
+
+	for _, tt := range useCases {
+		err := tt.original.DeleteAt(tt.pos)
+		if !reflect.DeepEqual(tt.original.inner, tt.modified.inner) || err != tt.err {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.modified, tt.original)
+		}
+	}
+}
+
+func TestSlice_Contains(t *testing.T) {
+	useCases := []struct {
+		description string
+		slice       *Slice[int]
+		item        int
+		want        bool
+	}{
+		{description: "empty slice contain item", slice: NewSlice[int](), item: 0, want: false},
+		{description: "slice with items search item no found", slice: NewSlice[int](1, 2, 3), item: 0, want: false},
+		{description: "slice with items search item found", slice: NewSlice[int](1, 2, 3), item: 3, want: true},
+	}
+
+	for _, tt := range useCases {
+		result := tt.slice.Contains(tt.item)
+		if result != tt.want {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.want, result)
+		}
+	}
+}
+
+func TestSlice_Index(t *testing.T) {
+	useCases := []struct {
+		description string
+		slice       *Slice[int]
+		item        int
+		pos         int
+		err         error
+	}{
+		{description: "empty slice contain item", slice: NewSlice[int](), item: 0, pos: 0, err: ErrItemNotFound{0}},
+		{description: "slice with items search item no found", slice: NewSlice[int](1, 2, 3), item: 0, pos: 0, err: ErrItemNotFound{0}},
+		{description: "slice with items search item found", slice: NewSlice[int](1, 2, 3), item: 3, pos: 2, err: nil},
+	}
+
+	for _, tt := range useCases {
+		pos, err := tt.slice.Index(tt.item)
+		if pos != tt.pos || err != tt.err {
+			t.Errorf("test: %s want {%v, %v} got {%v, %v}", tt.description, tt.pos, tt.err, pos, err)
+		}
+	}
+}

pkg/collection/stack.go

@@ -5,11 +5,6 @@ import (
 	"strings"
 )
 
-var (
-	// ErrEmptyStack is error when you have an empty stack structure
-	ErrEmptyStack = fmt.Errorf("this stack is empty")
-)
-
 // Stack is an structure with method for handle underlying slice as a stack.
 type Stack[E any] struct {
 	items []E
@@ -35,16 +30,16 @@ func (s *Stack[E]) Empty() bool {
 }
 
 // Top get first item in the stack structure, but
-// if stack is empty well this method return ErrEmptyStack error.
+// if stack is empty well this method return ErrEmptyCollection error.
 func (s *Stack[E]) Top() (E, error) {
 	if s.Empty() {
-		return *new(E), ErrEmptyStack
+		return *new(E), ErrEmptyCollection
 	}
 	return s.items[s.Size()-1], nil
 }
 
 // Pop get and remove first item in the stack structure, but
-// if stack is empty well this method return ErrEmptyStack error.
+// if stack is empty well this method return ErrEmptyCollection error.
 func (s *Stack[E]) Pop() (E, error) {
 	item, err := s.Top()
 	if err != nil {

pkg/collection/stack_test.go

@@ -16,7 +16,7 @@ var staticTests = []struct {
 	size        int
 	top         pair
 }{
-	{"empty stack", NewStack[int](), true, 0, pair{0, ErrEmptyStack}},
+	{"empty stack", NewStack[int](), true, 0, pair{0, ErrEmptyCollection}},
 	{"stack with items", NewStack(1, 2, 3), false, 3, pair{3, nil}},
 }
 
@@ -25,7 +25,7 @@ var popTests = []struct {
 	input       *Stack[int]
 	item        pair
 }{
-	{"empty stack pop item", NewStack[int](), pair{0, ErrEmptyStack}},
+	{"empty stack pop item", NewStack[int](), pair{0, ErrEmptyCollection}},
 	{"stack with items pop item", NewStack(1, 2, 3), pair{3, nil}},
 }