Add Set method in List interface

pkg/collection/collection.go

@@ -25,6 +25,7 @@ type List[E any] interface {
 	Front() (E, error)
 	PushBack(item E)
 	PushFront(item E)
+	Set(item E, pos int) error
 	Index(item E) (int, error)
 	GetAt(pos int) (E, error)
 	PushAt(item E, pos int)

pkg/collection/linked_list.go

@@ -230,6 +230,20 @@ func (l *LinkedList[E]) DeleteAt(pos int) error {
 	return nil
 }
 
+func (l *LinkedList[E]) Set(item E, pos int) error {
+	n, err := l.findNode(pos)
+	if err != nil {
+		return err
+	}
+
+	if n == nil {
+		return ErrNodeNotFound
+	}
+
+	n.value = item
+	return nil
+}
+
 func (l *LinkedList[E]) String() string {
 	var sb strings.Builder
 	sb.WriteString("[")

pkg/collection/linked_list_test.go

@@ -230,6 +230,63 @@ func TestLinkedList_PushFront(t *testing.T) {
 	}
 }
 
+func TestLinkedList_Set(t *testing.T) {
+	useCases := []struct {
+		description string
+		original    *LinkedList[int]
+		modified    *LinkedList[int]
+		pos         int
+		item        int
+		err         error
+	}{
+		{description: "change item in first position in singleton list",
+			original: NewLinkedList[int](0),
+			modified: NewLinkedList(1),
+			pos:      0,
+			item:     1},
+		{description: "change item in first position in full list",
+			original: NewLinkedList(1, 2, 3),
+			modified: NewLinkedList(0, 2, 3),
+			pos:      0,
+			item:     0},
+		{description: "change item in middle position in full list",
+			original: NewLinkedList(1, 2, 3),
+			modified: NewLinkedList(1, 0, 3),
+			pos:      1,
+			item:     0},
+		{description: "add item in last position in full list",
+			original: NewLinkedList(1, 2, 3),
+			modified: NewLinkedList(1, 2, 0),
+			pos:      2,
+			item:     0},
+		{description: "no items in list return ErrEmptyCollection",
+			original: NewLinkedList[int](),
+			modified: NewLinkedList[int](),
+			pos:      0,
+			item:     0,
+			err:      ErrEmptyCollection},
+		{description: "get item with negative position",
+			original: NewLinkedList(1, 2, 3),
+			modified: NewLinkedList(1, 2, 3),
+			pos:      -1,
+			item:     0,
+			err:      ErrPositionNegative},
+		{description: "get item with index out of bound",
+			original: NewLinkedList(1, 2, 3),
+			modified: NewLinkedList(1, 2, 3),
+			pos:      4,
+			item:     0,
+			err:      ErrIndexOutOfBound{4, 3}},
+	}
+
+	for _, tt := range useCases {
+		err := tt.original.Set(tt.item, tt.pos)
+		if !compareLists(tt.original, tt.modified) || tt.err != err {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.modified, tt.original)
+		}
+	}
+}
+
 func TestLinkedList_Delete(t *testing.T) {
 	useCases := []struct {
 		description string

pkg/collection/slice.go

@@ -158,6 +158,20 @@ func (s *Slice[E]) Index(item E) (int, error) {
 	return 0, ErrItemNotFound{item}
 }
 
+func (s *Slice[E]) Set(item E, pos int) error {
+	if s.Empty() {
+		return ErrEmptyCollection
+	}
+	if pos < 0 {
+		return ErrPositionNegative
+	}
+	if pos < 0 || pos >= s.Size() {
+		return ErrIndexOutOfBound{pos, s.Size()}
+	}
+	s.inner[pos] = item
+	return nil
+}
+
 func (s *Slice[E]) String() string {
 	var sb strings.Builder
 	sb.WriteString("[")

pkg/collection/slice_test.go

@@ -328,3 +328,60 @@ func TestSlice_Index(t *testing.T) {
 		}
 	}
 }
+
+func TestSlice_Set(t *testing.T) {
+	useCases := []struct {
+		description string
+		original    *Slice[int]
+		modified    *Slice[int]
+		pos         int
+		item        int
+		err         error
+	}{
+		{description: "change item in first position in singleton list",
+			original: NewSlice[int](0),
+			modified: NewSlice(1),
+			pos:      0,
+			item:     1},
+		{description: "change item in first position in full list",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(0, 2, 3),
+			pos:      0,
+			item:     0},
+		{description: "change item in middle position in full list",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(1, 0, 3),
+			pos:      1,
+			item:     0},
+		{description: "add item in last position in full list",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(1, 2, 0),
+			pos:      2,
+			item:     0},
+		{description: "no items in list return ErrEmptyCollection",
+			original: NewSlice[int](),
+			modified: NewSlice[int](),
+			pos:      0,
+			item:     0,
+			err:      ErrEmptyCollection},
+		{description: "get item with negative position",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(1, 2, 3),
+			pos:      -1,
+			item:     0,
+			err:      ErrPositionNegative},
+		{description: "get item with index out of bound",
+			original: NewSlice(1, 2, 3),
+			modified: NewSlice(1, 2, 3),
+			pos:      4,
+			item:     0,
+			err:      ErrIndexOutOfBound{4, 3}},
+	}
+
+	for _, tt := range useCases {
+		err := tt.original.Set(tt.item, tt.pos)
+		if !reflect.DeepEqual(tt.original, tt.modified) || tt.err != err {
+			t.Errorf("test: %s want %v got %v", tt.description, tt.modified, tt.original)
+		}
+	}
+}