Reverse Linked List in Go/Golang

ReverseLinkedList.go

package Helpers

import (
	"testing"
)

type Node struct {
	data interface{}
	prev *Node
}

type LinkedList struct {
	Size int32
	head *Node
}

func (list *LinkedList) Add(data int32) {
	element := new(Node)
	element.data = data
	element.prev = list.head
	list.head = element
	list.Size++
}

func (list *LinkedList) Get(index int32) interface{} {
	if list.head == nil {
		return 0
	}

	v := list.head.data
	list.head  = list.head.prev
	list.Size--

	return v
}

func (list *LinkedList) List() []interface{} {
	if list.head == nil {
		return []interface{}{}
	}

	var result []interface{}
	var node = list.head

	for node.prev != nil {
		result = append(result,node.data)
		node = node.prev
	}

	result = append(result,node.data)

	return result
}

func (list *LinkedList) Reverse() {

	node := list.head
	var prev *Node

	for node != nil {
		node, prev, node.prev = node.prev, node, prev
	}

	list.head = prev

}

func (list *LinkedList) IsEmpty() bool {
	return list.head == nil
}


func Test_LinkedList(t *testing.T) {

	testDatas := []struct{
		datas []int32
		result []int32
	} {
		// result in original list and it will be reversed in test
		{[]int32{},[]int32{}},
		{[]int32{7},[]int32{7}},
		{[]int32{0,9,7,6,4,2,1,6},[]int32{6,1,2,4,6,7,9,0}},
		{[]int32{3,4,5,6,7},[]int32{7,6,5,4,3}},

	}

	for _, td := range testDatas {

		var i int
		var list = LinkedList{}

		for _, v := range td.datas {
			list.Add(v)
		}

		var result = list.List()

		// Test Original
		if len(td.result) != len(result) {
			t.Fail()
		}

		i = len(td.result) -1
		for i >= 0 {
			if result[i] != td.result[i] {
				t.Fail()
			}
			i--
		}


		// Test Reversed
		for i, j := 0, len(td.result)-1; i < j; i, j = i+1, j-1 {
			td.result[i], td.result[j] = td.result[j], td.result[i]
		}

		list.Reverse()
		result = list.List()

		if len(td.result) != len(result) {
			t.Fail()
		}

		i = len(td.result) -1
		for i >= 0 {
			if result[i] != td.result[i] {
				t.Fail()
			}
			i--
		}
	}
}