test(e2e): assert send return values, not just data convergence

The send path's status/version reporting had no e2e coverage — both the spurious
gap and the optimistic-version regression moved data correctly while reporting the
wrong status, so data-only assertions missed them. Add two helpers:

- db_send_ok(): run a send expected to succeed and assert it did not fail at the
  protocol level (status != "error", no send.lastFailure) — catches a
  server-reported apply/check failure that does not raise a SQL error, which a
  plain db_exec of the send ignored. Applied at the basic and chunked primary send
  sites (not the two failure-path tests, nor the best-effort in-loop sends).
- db_send_await_converge(): send, then poll until send.serverVersion reaches
  send.localVersion (durably covered, no gap), robust to the server's async apply.
  test_send_gap_from_clock_hole now uses it instead of a single synchronous assert.

Full e2e suite (incl. chunked) green against a live server.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: andinux

test/integration.c

@@ -236,6 +236,35 @@ int db_expect_min (sqlite3 *db, const char *sql, int expect_min) {
     return SQLITE_OK;
 }
 
+// Run a send that is expected to succeed and assert it didn't fail at the protocol
+// level: status is not "error" and the server reported no per-chunk failure
+// (send.lastFailure is omitted on success). Catches a server-reported apply/check
+// failure that doesn't raise a SQL error — invisible to a plain db_exec of the send.
+int db_send_ok (sqlite3 *db) {
+    return db_expect_int(db,
+        "SELECT (j ->> '$.send.status') <> 'error' AND (j ->> '$.send.lastFailure') IS NULL "
+        "FROM (SELECT cloudsync_network_send_changes() AS j);", 1);
+}
+
+// Send, then poll until the server's optimistic version (send.serverVersion) catches
+// up to send.localVersion — the change is durably covered with no gap. Robust to the
+// server's asynchronous apply: the first call sends, later calls are no-ops that
+// re-read status. Fails if it has not converged within max_attempts.
+int db_send_await_converge (sqlite3 *db, int max_attempts, int delay_ms) {
+    const char *sql =
+        "SELECT (j ->> '$.send.serverVersion') >= (j ->> '$.send.localVersion') "
+        "FROM (SELECT cloudsync_network_send_changes() AS j);";
+    for (int i = 0; i < max_attempts; i++) {
+        int converged = 0;
+        int rc = db_select_int(db, sql, &converged);
+        if (rc != SQLITE_OK) return rc;
+        if (converged) return SQLITE_OK;
+        if (i + 1 < max_attempts) sqlite3_sleep(delay_ms);
+    }
+    printf("Error: send did not converge (serverVersion < localVersion) after %d attempts\n", max_attempts);
+    return SQLITE_ERROR;
+}
+
 int integration_network_init(sqlite3 *db, const char *database_id, char *network_init, size_t network_init_len) {
     if (!database_id) {
         fprintf(stderr, "Error: integration database ID not set.\n");
@@ -528,7 +557,7 @@ int test_enable_disable(const char *db_path) {
         rc = db_exec(db, set_apikey); RCHECK
     }
 
-    rc = db_exec(db, "SELECT cloudsync_network_send_changes();"); RCHECK
+    rc = db_send_ok(db); RCHECK
     rc = db_exec(db, "SELECT cloudsync_cleanup('users');"); RCHECK
     rc = db_exec(db, "SELECT cloudsync_cleanup('activities');"); RCHECK
     rc = db_exec(db, "SELECT cloudsync_cleanup('workouts');"); RCHECK
@@ -624,14 +653,11 @@ int test_send_gap_from_clock_hole(const char *db_path) {
         rc = db_exec(db, set_apikey); RCHECK
     }
 
-    // Send once. The server applies the change and computes lastOptimisticVersion
-    // (serverVersion) synchronously from its per-site applied ranges. With contiguous
-    // coverage it reaches localVersion (10); with the gap bug it stays at 0 because
-    // db_versions 1..9 are reported missing.
-    rc = db_expect_int(db,
-        "SELECT (j ->> '$.send.serverVersion') = (j ->> '$.send.localVersion') "
-        "       AND (j ->> '$.send.localVersion') = 10 "
-        "FROM (SELECT cloudsync_network_send_changes() AS j);", 1); RCHECK
+    // Send, then poll until the server's optimistic version (serverVersion) reaches
+    // localVersion (10). With contiguous coverage it converges; with the gap bug it
+    // never does — serverVersion stays at 0 because db_versions 1..9 are reported
+    // missing. Polling absorbs the server's asynchronous apply.
+    rc = db_send_await_converge(db, 8, 1000); RCHECK
 
     rc = db_exec(db, "SELECT cloudsync_cleanup('users');"); RCHECK
     rc = db_exec(db, "SELECT cloudsync_cleanup('activities');"); RCHECK
@@ -665,7 +691,7 @@ int test_chunked_payload_paths(void) {
     rc = db_expect_min(sender, "SELECT COUNT(*) FROM cloudsync_payload_chunks();", 2); if (rc != SQLITE_OK) goto cleanup;
     rc = db_expect_min(sender, "SELECT COUNT(*) FROM cloudsync_payload_chunks() WHERE hex(substr(payload,5,1))='03';", 2); if (rc != SQLITE_OK) goto cleanup;
 
-    rc = db_exec(sender, "SELECT cloudsync_network_send_changes();"); if (rc != SQLITE_OK) goto cleanup;
+    rc = db_send_ok(sender); if (rc != SQLITE_OK) goto cleanup;
     cleanup_remote_row = true;
 
     for (int attempt = 0; attempt < 30; ++attempt) {
@@ -738,7 +764,7 @@ int test_chunked_payload_rowset_path(void) {
     rc = db_expect_min(sender, "SELECT COUNT(*) FROM cloudsync_payload_chunks();", 2); if (rc != SQLITE_OK) goto cleanup;
     rc = db_expect_int(sender, "SELECT COUNT(*) FROM cloudsync_payload_chunks() WHERE hex(substr(payload,5,1))='03';", 0); if (rc != SQLITE_OK) goto cleanup;
 
-    rc = db_exec(sender, "SELECT cloudsync_network_send_changes();"); if (rc != SQLITE_OK) goto cleanup;
+    rc = db_send_ok(sender); if (rc != SQLITE_OK) goto cleanup;
     cleanup_remote_rows = true;
 
     for (int attempt = 0; attempt < 30; ++attempt) {
@@ -822,7 +848,7 @@ int test_chunked_payload_single_sync_drain(void) {
     // Sender splits into multiple non-fragment chunks.
     rc = db_expect_min(sender, "SELECT COUNT(*) FROM cloudsync_payload_chunks();", 2); if (rc != SQLITE_OK) goto cleanup;
 
-    rc = db_exec(sender, "SELECT cloudsync_network_send_changes();"); if (rc != SQLITE_OK) goto cleanup;
+    rc = db_send_ok(sender); if (rc != SQLITE_OK) goto cleanup;
     cleanup_remote_rows = true;
 
     for (int attempt = 0; attempt < 40; ++attempt) {
@@ -921,7 +947,7 @@ int test_chunked_payload_capped_receive(void) {
 
     rc = db_expect_min(sender, "SELECT COUNT(*) FROM cloudsync_payload_chunks();", 2); if (rc != SQLITE_OK) goto cleanup;
 
-    rc = db_exec(sender, "SELECT cloudsync_network_send_changes();"); if (rc != SQLITE_OK) goto cleanup;
+    rc = db_send_ok(sender); if (rc != SQLITE_OK) goto cleanup;
     cleanup_remote_rows = true;
 
     for (int attempt = 0; attempt < 80; ++attempt) {
@@ -1017,7 +1043,7 @@ int test_chunked_payload_batched_receive(void) {
 
     rc = db_expect_min(sender, "SELECT COUNT(*) FROM cloudsync_payload_chunks();", 3); if (rc != SQLITE_OK) goto cleanup;
 
-    rc = db_exec(sender, "SELECT cloudsync_network_send_changes();"); if (rc != SQLITE_OK) goto cleanup;
+    rc = db_send_ok(sender); if (rc != SQLITE_OK) goto cleanup;
     cleanup_remote_rows = true;
 
     for (int attempt = 0; attempt < 80; ++attempt) {
@@ -1189,7 +1215,7 @@ int test_chunked_negative_cache_invalidation(void) {
         "INSERT INTO chunked_payload_items (id, body) VALUES ('%s', 'negative-cache-sentinel');",
         sentinel_id);
     rc = db_exec(sender, sql); if (rc != SQLITE_OK) goto cleanup;
-    rc = db_exec(sender, "SELECT cloudsync_network_send_changes();"); if (rc != SQLITE_OK) goto cleanup;
+    rc = db_send_ok(sender); if (rc != SQLITE_OK) goto cleanup;
     cleanup_sentinel = true;
 
     // Phase 1: drain the receiver until it is provably caught up. Each bare
@@ -1267,7 +1293,7 @@ int test_chunked_negative_cache_invalidation(void) {
         "INSERT INTO chunked_payload_items (id, body) VALUES ('%s', 'negative-cache');",
         row_id);
     rc = db_exec(sender, sql); if (rc != SQLITE_OK) goto cleanup;
-    rc = db_exec(sender, "SELECT cloudsync_network_send_changes();"); if (rc != SQLITE_OK) goto cleanup;
+    rc = db_send_ok(sender); if (rc != SQLITE_OK) goto cleanup;
     cleanup_remote_row = true;
 
     // Phase 4: the receiver must now pick up the change on a subsequent receive.