JAVASCRIPT

what to do when node was already in close in A* algorithm

14 if node_successor is on the CLOSED list but the existing one is as good 
   or better then discard this successor and continue

what to do when node was already in close in A* algorithm

Get the square on the open list which has the lowest score. Let’s call this square S.
Remove S from the open list and add S to the closed list.
For each square T in S’s walkable adjacent tiles:
If T is in the closed list: Ignore it.
If T is not in the open list: Add it and compute its score.
If T is already in the open list: Check if the F score is lower when we use the current generated path to get there. If it is, update its score and update its parent as well.