java - Count number of Insertions in BST -

i have bst class of strings global variable called numinsertions counts number of insertions bst. not sure gives correct results not know recursion well, please me verify

public void insert(string key)   {     if(isempty())     {       root = new node(key);       numinsertions++;     }     else       numinsertions = 1+insert(key, root);   }   public int insert(string key, node curr)   {     int result = 1;     if(key.compareto(curr.getkey())<0)     {       if(curr.getleftchild()==null)       {         node newnode = new node(key);         curr.setleftchild(newnode);       }       else         result = result +insert(key,curr.getleftchild());     }     else     {       if(curr.getrightchild()==null)       {         node newnode = new node(key);         curr.setrightchild(newnode);       }       else         result = result +insert(key,curr.getrightchild());     }     return result;   } 

write test case class , test class behaving properly. let's class named bst , can access instance variable 'numberofinserts' method named 'size()', simple test case testing insertions (without 3rd party libraries) placed in main method of test class. like:

bst bst = new bst(); //test insertion of 100 items ( int = 0; < 100; i++ ){     bst.insert(string.valueof(i));     if ( bst.size() != i+1 ){         throw new exception("invalid bst size " + bst.size());     } } 

in example, exception thrown if class not behave properly. if misbehaves, can step debugger (or use system.out.println) try , debug application.