tracks/python/exercises/collatz-conjecture/example.py in trackler-2.2.1.107 vs tracks/python/exercises/collatz-conjecture/example.py in trackler-2.2.1.108

@@ -1,7 +1,7 @@
 def collatz_steps(n):
     if n <= 0:
-        return
+        raise ValueError("input should be positive")
 
     step_count = 0
     while n > 1:
         if is_odd(n):
             n = n * 3 + 1