NERDTree custom mappings to make i and s reuse existing windows

hax0r.vim

call NERDTreeAddKeyMap({                                                                                                                
       \ 'key': 'i',                                                                                                                    
       \ 'scope': 'FileNode',                                                                                                           
       \ 'callback': "NERDTreeCustomOpenSplit",                                                                                         
       \ 'quickhelpText': 'open split reusing if able' })                                                                               
                                                                                                                                        
function! NERDTreeCustomOpenSplit(node)                                                                                                 
    call a:node.open({'split': 'h', 'reuse': 1})                                                                                        
endfunction                                                                                                                             
                                                                                                                                        
call NERDTreeAddKeyMap({                                                                                                                
       \ 'key': 's',                                                                                                                    
       \ 'scope': 'FileNode',                                                                                                           
       \ 'callback': "NERDTreeCustomOpenVSplit",                                                                                        
       \ 'quickhelpText': 'open vsplit reusing if able' })                                                                              
                                                                                                                                        
function! NERDTreeCustomOpenVSplit(node)                                                                                                 
    call a:node.open({'split': 'v', 'reuse': 1})                                                                                        
endfunction