Αυτό μπορεί να γίνει γράφοντας ειδικό κώδικα για να ελέγχει κάθε
τμήμα.
Παράδειγμα:
...
main()
{
        process('/');
        process('*');
        if (state == COMMENT)
                printf("Test 1 OK");
        else
                printf("Test 1 FAIL: Comment enter error");
        state = COMMENT;
        process('*');
        process(' ');
        process('/');
        if (state == COMMENT)
                printf("Test 2 OK");
        else
                printf("Test 2 FAIL: Comment end error");
        state = COMMENT;
        process('*');
        process('/');
        if (state != COMMENT)
                printf("Test 3 OK");
        else
                printf("Test 3 FAIL: Comment end error");
        printf("Test 4: Bellow you should see:\n[\t\t\t]\n");
        indent_level = 3;
        putchar('[');
        indent();
        printf("]\n");
}