Test the libc wrappers: 52% -> 99% line coverage

Every wrapper outside the list and tree code was untested. Six new test
files close that, following the plan already written in TODO.md 1.2-1.6:

  test_stream.c   fopen/fread/fwrite/fclose -- happy paths, the round
                  trip, AKERR_EOF on a short read, AKERR_IO on a stream
                  opened in the wrong mode, ENOENT, and the NULL guards
  test_format.c   printf/fprintf/sprintf -- text *and* count asserted
                  (stdout is pointed at a temp file to check aksl_printf),
                  all eight NULL guards, EBADF on a read-only stream, and
                  512 variadic calls in a loop as sanitizer cover for the
                  missing va_end
  test_convert.c  ato{i,l,ll,f} happy paths, negatives, leading
                  whitespace, NULL guards
  test_path.c     realpath on a file and on a symlink, both compared
                  against realpath(3) since TMPDIR may itself be a link;
                  ENOENT, ENOTDIR, NULL path
  test_strhash.c  djb2 known-answer vectors, len == 0, embedded NUL,
                  stability, NULL guards
  test_convert_strict.c
                  known-failing (2.1.5): the AKERR_VALUE / ERANGE
                  contract the ato* family cannot express today

test_tree.c gains the BFS AKERR_NOT_IMPLEMENTED contract, NULL arguments,
and a callback error that is not AKERR_ITERATOR_BREAK propagating out.

Tests deliberately say nothing about behaviour TODO.md records as
defective -- unchecked ptr/mode/resolved_path, short transfers reported as
success, *count left at -1, the djb2 sign extension -- so the eventual fix
does not have to come with a test rewrite. Each failure case in
test_path.c passes a zeroed buffer, because the wrapper's own error path
formats resolved_path with %s (2.1.6).

aksl_capture.h gains aksl_temp_file() with an atexit unlink backstop.
Without it every test that fails before its own unlink leaves temp files
behind -- which is the normal case for a known-failing test, and happens
173 times over in a mutation run.

Coverage on src/stdlib.c: 52.0% -> 99.0% of lines (200/202), 23.6% ->
51.0% of branches, 8/21 -> 21/21 functions. The two uncovered lines are
both `} HANDLE(e, AKERR_ITERATOR_BREAK) {`, where the macro starts with
the `break;` of PROCESS's `case 0:` arm -- reachable only via a non-NULL
error context whose status is zero, the pathology 2.2.1 exists to remove.

Mutation score on src/stdlib.c: 46.8% -> 89.6% (155/173 killed). CI, the
pre-push hook and the docs ratchet from 40 to 80 accordingly, and the 18
survivors are grouped by cause in TODO.md and README.md. A new CI
coverage job gates at 90% lines / 45% branches.

Verified:
  ctest --test-dir build            # 12/12
  ctest --test-dir build-asan       # 12/12 under ASan + UBSan
  ctest --test-dir build-coverage   # 14/14, report attached
  ctest --test-dir build -j8 --repeat until-fail:3
  gcc -Wall -Wextra -c on all nine test files  # no warnings
  python3 scripts/mutation_test.py --target src/stdlib.c  # 89.6%
No temp files left in /tmp after any of the above.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-07-30 02:07:08 -04:00
parent 82c47ed773
commit 437da2960b
14 changed files with 1138 additions and 73 deletions

188
tests/test_stream.c Normal file
View File

@@ -0,0 +1,188 @@
/*
* Stream wrappers: aksl_fopen / aksl_fread / aksl_fwrite / aksl_fclose.
*
* TODO.md section 1.2. Covered here: the happy paths, the round trip, the NULL
* guards that exist, and the two error statuses the wrappers can actually
* produce today -- AKERR_EOF from a short read and AKERR_IO from a stream whose
* error indicator is set.
*
* Not covered, because the behaviour is a documented gap rather than a
* contract: aksl_fopen(NULL, ...) and aksl_fopen(path, NULL, ...) are unchecked
* (2.2.2), aksl_fread/aksl_fwrite never check ptr and report a short transfer
* that is neither EOF nor error as complete success (2.2.3).
*
* Temp files come from aksl_temp_file() and are unlinked by the test that made
* them, so a failing test leaves nothing behind but the file it was mid-way
* through.
*/
#include "aksl_capture.h"
#include <errno.h>
static int test_fopen_writes_stream_pointer(void)
{
char path[AKSL_TMP_MAX];
FILE *fp = NULL;
AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
AKSL_CHECK_OK(aksl_fopen(path, "w", &fp));
AKSL_CHECK(fp != NULL);
AKSL_CHECK_OK(aksl_fclose(fp));
AKSL_CHECK(unlink(path) == 0);
return 0;
}
static int test_fopen_reports_missing_path(void)
{
FILE *fp = NULL;
/* The pathname belongs in the message; the status is the errno fopen saw. */
AKSL_CHECK_STATUS_MSG_CONTAINS(
aksl_fopen("/nonexistent/aksl/stream", "r", &fp),
ENOENT, "/nonexistent/aksl/stream");
return 0;
}
static int test_fopen_rejects_null_stream_out(void)
{
char path[AKSL_TMP_MAX];
AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_fopen(path, "r", NULL),
AKERR_NULLPOINTER, "NULL");
AKSL_CHECK(unlink(path) == 0);
return 0;
}
/* fopen -> fwrite -> fclose -> fopen -> fread -> compare, all through the wrappers. */
static int test_write_read_round_trip(void)
{
char path[AKSL_TMP_MAX];
char payload[] = "libakstdlib round trip";
char readback[sizeof(payload)];
FILE *fp = NULL;
AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
AKSL_CHECK_OK(aksl_fopen(path, "w", &fp));
AKSL_CHECK_OK(aksl_fwrite(payload, 1, sizeof(payload), fp));
AKSL_CHECK_OK(aksl_fclose(fp));
fp = NULL;
memset(readback, 0x00, sizeof(readback));
AKSL_CHECK_OK(aksl_fopen(path, "r", &fp));
AKSL_CHECK_OK(aksl_fread(readback, 1, sizeof(readback), fp));
AKSL_CHECK_OK(aksl_fclose(fp));
AKSL_CHECK(memcmp(payload, readback, sizeof(payload)) == 0);
AKSL_CHECK(unlink(path) == 0);
return 0;
}
/* Asking for more members than the file holds sets feof, which is AKERR_EOF. */
static int test_fread_short_read_is_eof(void)
{
char path[AKSL_TMP_MAX];
char buf[32];
FILE *fp = NULL;
AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
AKSL_CHECK_OK(aksl_fopen(path, "w", &fp));
AKSL_CHECK_OK(aksl_fwrite("abcd", 1, 4, fp));
AKSL_CHECK_OK(aksl_fclose(fp));
fp = NULL;
memset(buf, 0x00, sizeof(buf));
AKSL_CHECK_OK(aksl_fopen(path, "r", &fp));
AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_fread(buf, 1, sizeof(buf), fp),
AKERR_EOF, "EOF");
AKSL_CHECK_OK(aksl_fclose(fp));
/* The bytes that did arrive are still in the buffer. */
AKSL_CHECK(memcmp(buf, "abcd", 4) == 0);
AKSL_CHECK(unlink(path) == 0);
return 0;
}
/*
* A stream opened "w" has no read permission, so fread sets the error indicator
* rather than the EOF one: AKERR_IO, not AKERR_EOF.
*/
static int test_fread_from_write_only_stream_is_io_error(void)
{
char path[AKSL_TMP_MAX];
char buf[4];
FILE *fp = NULL;
AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
AKSL_CHECK_OK(aksl_fopen(path, "w", &fp));
memset(buf, 0x00, sizeof(buf));
AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_fread(buf, 1, sizeof(buf), fp),
AKERR_IO, "Error reading file");
AKSL_CHECK_OK(aksl_fclose(fp));
AKSL_CHECK(unlink(path) == 0);
return 0;
}
static int test_fread_rejects_null_stream(void)
{
char buf[4];
memset(buf, 0x00, sizeof(buf));
AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_fread(buf, 1, sizeof(buf), NULL),
AKERR_NULLPOINTER, "NULL");
return 0;
}
/* Mirror image of the fread case: a "r" stream cannot be written to. */
static int test_fwrite_to_read_only_stream_is_io_error(void)
{
char path[AKSL_TMP_MAX];
FILE *fp = NULL;
AKSL_CHECK(aksl_temp_file(path, sizeof(path)) == 0);
AKSL_CHECK_OK(aksl_fopen(path, "r", &fp));
AKSL_CHECK_STATUS(aksl_fwrite("xy", 1, 2, fp), AKERR_IO);
AKSL_CHECK_OK(aksl_fclose(fp));
AKSL_CHECK(unlink(path) == 0);
return 0;
}
static int test_fwrite_rejects_null_stream(void)
{
AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_fwrite("xy", 1, 2, NULL),
AKERR_NULLPOINTER, "NULL");
return 0;
}
static int test_fclose_rejects_null_stream(void)
{
AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_fclose(NULL),
AKERR_NULLPOINTER, "NULL");
return 0;
}
int main(void)
{
int failures = 0;
akerr_init();
AKSL_RUN(failures, test_fopen_writes_stream_pointer);
AKSL_RUN(failures, test_fopen_reports_missing_path);
AKSL_RUN(failures, test_fopen_rejects_null_stream_out);
AKSL_RUN(failures, test_write_read_round_trip);
AKSL_RUN(failures, test_fread_short_read_is_eof);
AKSL_RUN(failures, test_fread_from_write_only_stream_is_io_error);
AKSL_RUN(failures, test_fread_rejects_null_stream);
AKSL_RUN(failures, test_fwrite_to_read_only_stream_is_io_error);
AKSL_RUN(failures, test_fwrite_rejects_null_stream);
AKSL_RUN(failures, test_fclose_rejects_null_stream);
AKSL_REPORT(failures);
}