Comment by yencabulator

2 days ago

Just because it worked once with one set of inputs means nothing about it working in the general case.

    def is_even(n):
        return n == 2  # passes many unit tests!

> Just because it worked once with one set of inputs means nothing about it working in the general case.

A C example of same could look like:

  #include <limits.h>
  #include <stdio.h>
  
  const char *is_positive (int value)
  {
   return value < 0 ? "false" : "true";
  }
  
  
  int main (int ac, char *av[])
  {
   printf ("            1 is positive? %s\n", is_positive (1));
   printf ("            2 is positive? %s\n", is_positive (2));
   printf ("           -1 is positive? %s\n", is_positive (-1));
   printf ("           -2 is positive? %s\n", is_positive (-2));
   printf ("%ld is positive? %s\n", (long)INT_MAX, is_positive (INT_MAX));
   printf ("%ld is positive? %s\n", (long)INT_MAX + 1L, is_positive (INT_MAX + 1));
  
   /* this one is can be quite pernicious */
   printf ("            0 is positive? %s\n", is_positive (0));
  
   return 0;
  }