David needs to test a function that compares dates (in C) with the following spe
ID: 666875 • Letter: D
Question
David needs to test a function that compares dates (in C) with the following specification:
/* returns 0 if date1 = date2, -1 if date1 before date2, 1 if date1 after date2,
-2 if any element of any date is invalid;
valid years are all integers (<0 = BC); valid month is 1-12; valid day is
1-{28,29,30,31} depending on the year and month */
int compdate(int year1, int month1, int day1, int year2, int month2, int day2);
He proposes a random testing scheme, running 2,000,000 tests where each test is
performed by the following function:
int oneTest() {
int y1 = random_int(); /* returns a random 32 bit value */
int y2 = random_int();
int m1 = (random_int() % 11) + 1;
int m2 = (random_int() % 11) + 1;
int d1 = (random_int() % 30) + 1;
int d2 = (random_int() % 30) + 1;
int c1 = compdate(y1,m1,d1,y2,m2,d2);
int c2 = compdateOracle(y1,m1,d1,y2,m2,d2);
Assert(c1 == c2, "Issue with compdate function");
}
Assuming that compdateOracle is a perfect function without any bug to compare dates, Find out 3 issues with this random testing scheme. For each of the issue found, propose an improvement. Mention issue in one line and improvement proposal in less then 3 lines. Find out logical issue, don't look for typos and coding errors.
David needs to test a function that compares dates (in C) with the following specification:
/* returns 0 if date1 = date2, -1 if date1 before date2, 1 if date1 after date2,
-2 if any element of any date is invalid;
valid years are all integers (<0 = BC); valid month is 1-12; valid day is
1-{28,29,30,31} depending on the year and month */
int compdate(int year1, int month1, int day1, int year2, int month2, int day2);
He proposes a random testing scheme, running 2,000,000 tests where each test is
performed by the following function:
int oneTest() {
int y1 = random_int(); /* returns a random 32 bit value */
int y2 = random_int();
int m1 = (random_int() % 11) + 1;
int m2 = (random_int() % 11) + 1;
int d1 = (random_int() % 30) + 1;
int d2 = (random_int() % 30) + 1;
int c1 = compdate(y1,m1,d1,y2,m2,d2);
int c2 = compdateOracle(y1,m1,d1,y2,m2,d2);
Assert(c1 == c2, "Issue with compdate function");
}
Assuming that compdateOracle is a perfect function without any bug to compare dates, Find out 3 issues with this random testing scheme. For each of the issue found, propose an improvement. Mention issue in one line and improvement proposal in less then 3 lines. Find out logical issue, don't look for typos and coding errors.
Explanation / Answer
Here some of issues I found...
1) int y1 = random_int();
this random int gives number which it may lies in boundary 0 to infinty ...
So in this statement issue occurs..since maximum year digits accepted is 4
solution
so change it to ...int y1 = random_int() /1000;
2) int d1 = (random_int() % 30) + 1;
In this statement we will get number of days where boundary lies between 1 to 31 which is good. But issue occurs when month february selected/...then it may given number of days as 30 or 31...so this woulb raise error.
Solution.. handle with if conditions ...for 6 months we have only 30 days and 5 months 31 days and one month 28 days
3) int c1 = compdate(y1,m1,d1,y2,m2,d2);
As already we discussed above problems....so when we comparing with those wrong values then it will wrong values..and may be throw exception..so use try catch exception class...