solution.js

var trie = createTrie(dictionary);

function findWords(board) {
  var count = 0;

  var visited = [];

  for (var x = 0; x < board.width; x++) {
    visited[x] = []
    for (var y = 0; y < board.height; y++) {
      visited[x][y] = false;
    }
  }

  for (var x = 0; x < board.width; x++) {
    for (var y = 0; y < board.height; y++) {
      count += findWordsAt(board, x, y, trie, visited);
    }
  }

  return count;
}

function findWordsAt(board, x, y, node, visited) {
  if (x < 0
    || x >= board.width
    || y < 0
    || y >= board.width
    || visited[x][y]
    || !node.hasChild(board.at(x, y))) {
    return 0;
  }

  visited[x][y] = true;

  var character = board.at(x, y);
  var currentNode = node.getChild(character);

  var wordCount = node.isLeaf ? 1 : 0;
  
  for (var offX = -1; offX < 2; offX++) {
    for (var offY = -1; offY < 2; offY++) {
      if (offX == 0 && offY == 0) continue;

      wordCount += findWordsAt(
        board,
        (x + offX + board.width) % board.width,
        (y + offY + board.height) % board.height,
        currentNode,
        visited);
    }
  }

  visited[x][y] = false;
  return wordCount;
}

var boggleBoard = new BoggleBoard(
  'happybirthdaylizhappybirthdaylizyouroneyearolderandstillverycoolnotnearlyasoldasnickandyourenotcatchingupbecausetimedoesnotworkthatwayhavefunsolvingthispuzzleihopeitspossible',
  29,
  6);
var count = findWords(boggleBoard);

alert(count);