Activity - Unit testing

Consider the simple one-function jhash module used in Lab3 and the TSE. It comprises jhash.c and jhash.h and implements the JenkinsHash() function below.

1. With your group, list all the tests a good unit test should run against this unit.
   • Can you spot the bug? (I just noticed one I’d overlooked before.)
   • If you have time,
   • download the above files, or copy them:
   • cp ~cs50/public_html/Labs/Lab3/starter/hashtable/jhash.[ch] .
   • extend jhash.c with a unit test like those we saw demonstrated in class today; you can #include "unittest.h" and copy that file from ~cs50/examples/unittest.h for your testing.

unsigned long
JenkinsHash(const char *str, unsigned long mod)
{
    if (str == NULL)
      return 0;

    size_t len = strlen(str);
    unsigned long hash, i;

    for (hash = i = 0; i < len; ++i)
    {
        hash += str[i];
        hash += (hash << 10);
        hash ^= (hash >> 6);
    }

    hash += (hash << 3);
    hash ^= (hash >> 11);
    hash += (hash << 15);

    return hash % mod;
}