Simple unit test in C of input using freopen
$begingroup$
Here is an initial attempt at unit test of user input in C. The thing that feels unusual is the use of freopen to send the test data to stdin. Are there better ways to implement this kind of test?
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
static size_t get_num(size_t tmpnum) {
if (scanf("%zu", &tmpnum) != 1) {
fprintf(stderr, "ERROR: system error: failed to read input, exiting.n");
exit(1);
}
return tmpnum;
}
int main(void)
{
int return_status = 0;
/* Test 1 */
if (freopen("test-data.txt", "r", stdin) != NULL) {
size_t tmpnum = 0;
tmpnum = get_num(tmpnum);
assert(tmpnum >= 1 && tmpnum <= 20);
printf("ok: tmpnum == %ldn", tmpnum);
freopen("/dev/stdin", "r", stdin);
} else {
printf("ERROR: failed to open test-data.txtn");
return_status = EXIT_FAILURE;
}
return return_status;
}
c unit-testing io
edited 20 mins ago
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add a comment |
$begingroup$
Here is an initial attempt at unit test of user input in C. The thing that feels unusual is the use of freopen to send the test data to stdin. Are there better ways to implement this kind of test?
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
static size_t get_num(size_t tmpnum) {
if (scanf("%zu", &tmpnum) != 1) {
fprintf(stderr, "ERROR: system error: failed to read input, exiting.n");
exit(1);
}
return tmpnum;
}
int main(void)
{
int return_status = 0;
/* Test 1 */
if (freopen("test-data.txt", "r", stdin) != NULL) {
size_t tmpnum = 0;
tmpnum = get_num(tmpnum);
assert(tmpnum >= 1 && tmpnum <= 20);
printf("ok: tmpnum == %ldn", tmpnum);
freopen("/dev/stdin", "r", stdin);
} else {
printf("ERROR: failed to open test-data.txtn");
return_status = EXIT_FAILURE;
}
return return_status;
}
c unit-testing io
edited 20 mins ago
200_success
129k15153415
asked 7 hours ago
Runway BluesRunway Blues
33
New contributor
Runway Blues is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
Here is an initial attempt at unit test of user input in C. The thing that feels unusual is the use of freopen to send the test data to stdin. Are there better ways to implement this kind of test?
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
static size_t get_num(size_t tmpnum) {
if (scanf("%zu", &tmpnum) != 1) {
fprintf(stderr, "ERROR: system error: failed to read input, exiting.n");
exit(1);
}
return tmpnum;
}
int main(void)
{
int return_status = 0;
/* Test 1 */
if (freopen("test-data.txt", "r", stdin) != NULL) {
size_t tmpnum = 0;
tmpnum = get_num(tmpnum);
assert(tmpnum >= 1 && tmpnum <= 20);
printf("ok: tmpnum == %ldn", tmpnum);
freopen("/dev/stdin", "r", stdin);
} else {
printf("ERROR: failed to open test-data.txtn");
return_status = EXIT_FAILURE;
}
return return_status;
}
c unit-testing io
edited 20 mins ago
200_success
129k15153415
asked 7 hours ago
Runway BluesRunway Blues
33
New contributor
Runway Blues is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
Here is an initial attempt at unit test of user input in C. The thing that feels unusual is the use of freopen to send the test data to stdin. Are there better ways to implement this kind of test?
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
static size_t get_num(size_t tmpnum) {
if (scanf("%zu", &tmpnum) != 1) {
fprintf(stderr, "ERROR: system error: failed to read input, exiting.n");
exit(1);
}
return tmpnum;
}
int main(void)
{
int return_status = 0;
/* Test 1 */
if (freopen("test-data.txt", "r", stdin) != NULL) {
size_t tmpnum = 0;
tmpnum = get_num(tmpnum);
assert(tmpnum >= 1 && tmpnum <= 20);
printf("ok: tmpnum == %ldn", tmpnum);
freopen("/dev/stdin", "r", stdin);
} else {
printf("ERROR: failed to open test-data.txtn");
return_status = EXIT_FAILURE;
}
return return_status;
}
c unit-testing io
c unit-testing io
edited 20 mins ago
200_success
129k15153415
asked 7 hours ago
Runway BluesRunway Blues
33
New contributor
Runway Blues is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 20 mins ago
200_success
129k15153415
asked 7 hours ago
Runway BluesRunway Blues
33
New contributor
Runway Blues is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 20 mins ago
200_success
129k15153415
edited 20 mins ago
200_success
129k15153415
edited 20 mins ago
200_success
129k15153415
129k15153415
asked 7 hours ago
Runway BluesRunway Blues
33
New contributor
Runway Blues is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 7 hours ago
Runway BluesRunway Blues
33
asked 7 hours ago
Runway BluesRunway Blues
33
33
New contributor
Runway Blues is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Runway Blues is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Runway Blues is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
1 Answer
1
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$begingroup$
The thing that feels unusual is the use of freopen to send the test data to stdin.
Are there better ways to implement this kind of test?
C has a freopen() footnote
The primary use of the
freopenfunction is to change the file associated with a standard text stream (stderr,stdin, orstdout), as those identifiers need not be modifiable lvalues to which the value returned by thefopenfunction may be assigned.
This looks like a good direct way to test code, although I'd expect stdout, strderr being re-opened to capture output.
Are there better ways
Enable all compiler warnings - save time.
The mismatch of specifier and type implies code is not efficiently using the 1st round of code improvement: Compiler warnings.
// printf("ok: tmpnum == %ldn", tmpnum);
printf("ok: tmpnum == %zun", tmpnum);
Code is strange in that it passes in tmpnum for no good reason.
//static size_t get_num(size_t tmpnum) {
// if (scanf("%zu", &tmpnum) != 1) {
static size_t get_num(void) {
size_t tmpnum;
if (scanf("%zu", &tmpnum) != 1) {
answered 34 mins ago
chuxchux
13.1k21344
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1 Answer
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votes
$begingroup$
The thing that feels unusual is the use of freopen to send the test data to stdin.
Are there better ways to implement this kind of test?
C has a freopen() footnote
The primary use of the
freopenfunction is to change the file associated with a standard text stream (stderr,stdin, orstdout), as those identifiers need not be modifiable lvalues to which the value returned by thefopenfunction may be assigned.
This looks like a good direct way to test code, although I'd expect stdout, strderr being re-opened to capture output.
Are there better ways
Enable all compiler warnings - save time.
The mismatch of specifier and type implies code is not efficiently using the 1st round of code improvement: Compiler warnings.
// printf("ok: tmpnum == %ldn", tmpnum);
printf("ok: tmpnum == %zun", tmpnum);
Code is strange in that it passes in tmpnum for no good reason.
//static size_t get_num(size_t tmpnum) {
// if (scanf("%zu", &tmpnum) != 1) {
static size_t get_num(void) {
size_t tmpnum;
if (scanf("%zu", &tmpnum) != 1) {
answered 34 mins ago
chuxchux
13.1k21344
$endgroup$
add a comment |
$begingroup$
The thing that feels unusual is the use of freopen to send the test data to stdin.
Are there better ways to implement this kind of test?
C has a freopen() footnote
The primary use of the
freopenfunction is to change the file associated with a standard text stream (stderr,stdin, orstdout), as those identifiers need not be modifiable lvalues to which the value returned by thefopenfunction may be assigned.
This looks like a good direct way to test code, although I'd expect stdout, strderr being re-opened to capture output.
Are there better ways
Enable all compiler warnings - save time.
The mismatch of specifier and type implies code is not efficiently using the 1st round of code improvement: Compiler warnings.
// printf("ok: tmpnum == %ldn", tmpnum);
printf("ok: tmpnum == %zun", tmpnum);
Code is strange in that it passes in tmpnum for no good reason.
//static size_t get_num(size_t tmpnum) {
// if (scanf("%zu", &tmpnum) != 1) {
static size_t get_num(void) {
size_t tmpnum;
if (scanf("%zu", &tmpnum) != 1) {
answered 34 mins ago
chuxchux
13.1k21344
$endgroup$
add a comment |
$begingroup$
The thing that feels unusual is the use of freopen to send the test data to stdin.
Are there better ways to implement this kind of test?
C has a freopen() footnote
The primary use of the
freopenfunction is to change the file associated with a standard text stream (stderr,stdin, orstdout), as those identifiers need not be modifiable lvalues to which the value returned by thefopenfunction may be assigned.
This looks like a good direct way to test code, although I'd expect stdout, strderr being re-opened to capture output.
Are there better ways
Enable all compiler warnings - save time.
The mismatch of specifier and type implies code is not efficiently using the 1st round of code improvement: Compiler warnings.
// printf("ok: tmpnum == %ldn", tmpnum);
printf("ok: tmpnum == %zun", tmpnum);
Code is strange in that it passes in tmpnum for no good reason.
//static size_t get_num(size_t tmpnum) {
// if (scanf("%zu", &tmpnum) != 1) {
static size_t get_num(void) {
size_t tmpnum;
if (scanf("%zu", &tmpnum) != 1) {
answered 34 mins ago
chuxchux
13.1k21344
$endgroup$
The thing that feels unusual is the use of freopen to send the test data to stdin.
Are there better ways to implement this kind of test?
C has a freopen() footnote
The primary use of the
freopenfunction is to change the file associated with a standard text stream (stderr,stdin, orstdout), as those identifiers need not be modifiable lvalues to which the value returned by thefopenfunction may be assigned.
This looks like a good direct way to test code, although I'd expect stdout, strderr being re-opened to capture output.
Are there better ways
Enable all compiler warnings - save time.
The mismatch of specifier and type implies code is not efficiently using the 1st round of code improvement: Compiler warnings.
// printf("ok: tmpnum == %ldn", tmpnum);
printf("ok: tmpnum == %zun", tmpnum);
Code is strange in that it passes in tmpnum for no good reason.
//static size_t get_num(size_t tmpnum) {
// if (scanf("%zu", &tmpnum) != 1) {
static size_t get_num(void) {
size_t tmpnum;
if (scanf("%zu", &tmpnum) != 1) {
answered 34 mins ago
chuxchux
13.1k21344
edited 16 mins ago
answered 34 mins ago
chuxchux
13.1k21344
answered 34 mins ago
chuxchux
13.1k21344
answered 34 mins ago
chuxchux
13.1k21344
13.1k21344
add a comment |
add a comment |
Runway Blues is a new contributor. Be nice, and check out our Code of Conduct.
Runway Blues is a new contributor. Be nice, and check out our Code of Conduct.
Runway Blues is a new contributor. Be nice, and check out our Code of Conduct.
Runway Blues is a new contributor. Be nice, and check out our Code of Conduct.
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