UCS, BFS, DFS search in js

search.js

var tree = {
        'A': ['B', 'C', 'D', 'E'],
        'B': ['A', 'F', 'G'],
        'C': ['A', 'H'],
        'D': ['A', 'I', 'J'],
        'E': ['A', 'K', 'L'],
        'F': ['B', 'G', 'M', 'N', 'O'],
        'G': ['B', 'F', 'P', 'Q', 'R'],
        'H': ['C', 'S'],
        'I': ['D'],
        'J': ['D', 'T', 'U'],
        'K': ['E'],
        'L': ['E', 'V'],
        'M': ['F'],
        'N': ['F'],
        'O': ['F'],
        'P': ['G'],
        'Q': ['G'],
        'R': ['G'],
        'S': ['H', 'W', 'X'],
        'T': ['J'],
        'U': ['J', 'Y', 'Z'],
        'V': ['L'],
        'W': ['S'],
        'X': ['S'],
        'Y': ['U'],
        'Z': ['U']
}


function addToArray(item , node){
  i = item.slice(); i.push(node) ; return i
}

function exists(array, node){
  return array.filter( (n) => n === node ).length > 0
}

function search(controller){

  console.log('------------------------\n', controller.name)

  var visited = [ startNode ]
  var list = []
  list.push( {node : startNode , history : [startNode]})

  while(list.length > 0){
    var node = controller.remove(list)
    var history = node.history
    console.log(history)
    node = node.node

    if (node === endNode){
      return true
    }

    for (let child of tree[node].filter( (node ) => !exists(visited, node )) ){

          visited.push(child)
          controller.add(list, {node : child ,history : addToArray(history, child) })
    }

  }

}

var startNode = 'A'
var endNode = 'Y'

// dfs()
search({
  name : 'depth first search',
  remove : (stack) =>  stack.pop(),
  add : (stack, child) => stack.push(child)
})

// bfs
search({
  name : 'breadth first search' ,
  remove : (queue) => queue.shift(),
  add : (queue, child) => queue.push(child)
})


// ucs
search({
  name : 'uniform cost search' ,
  remove : (stack) => stack.pop(),
  add : (stack , child ) => {
    stack.push(child)
    stack.sort( (lhs, rhs) => 1 )
  }
})