libakstdlib/tests/test_list_append_chain.c

/*
 * KNOWN FAILING -- TODO.md section 2.1.1
 *
 * aksl_list_append conflates Floyd cycle detection with finding the tail: the
 * `tail` cursor is assigned from `slow` *before* `slow` advances, so it tracks
 * the node behind the list midpoint rather than the last node. Appending to any
 * list of two or more nodes therefore overwrites an interior link and silently
 * drops every node after it.
 *
 * Appending n1..n4 to n0 produces the chain "n0 -> n4"; this test asserts the
 * correct "n0 -> n1 -> n2 -> n3 -> n4" and so fails until append is fixed.
 * It is registered in AKSL_KNOWN_FAILING_TESTS, which marks it WILL_FAIL; when
 * the fix lands, CTest will report it as unexpectedly passing, which is the
 * signal to move it into AKSL_TESTS.
 */

#include "aksl_capture.h"

#define CHAIN_LEN 5

static int test_append_builds_full_chain(void)
{
    aksl_ListNode node[CHAIN_LEN];
    aksl_ListNode *walk = NULL;
    int i = 0;

    memset((void *)node, 0x00, sizeof(node));

    for ( i = 1; i < CHAIN_LEN; i++ ) {
	AKSL_CHECK_OK(aksl_list_append(&node[0], &node[i]));
    }

    /* Forward links, head to tail. */
    walk = &node[0];
    for ( i = 0; i < CHAIN_LEN; i++ ) {
	AKSL_CHECK(walk == &node[i]);
	walk = walk->next;
    }
    AKSL_CHECK(walk == NULL);

    /* Back links, tail to head. */
    walk = &node[CHAIN_LEN - 1];
    for ( i = CHAIN_LEN - 1; i >= 0; i-- ) {
	AKSL_CHECK(walk == &node[i]);
	walk = walk->prev;
    }
    AKSL_CHECK(walk == NULL);

    return 0;
}

int main(void)
{
    int failures = 0;

    akerr_init();
    AKSL_RUN(failures, test_append_builds_full_chain);
    AKSL_REPORT(failures);
}