test-bus-util: add a test for destroy callbacks

src/test/test-bus-util.c

@@ -35,6 +35,48 @@ static void test_name_async(unsigned n_messages) {
         }
 }
 
+static int callback(sd_bus_message *m, void *userdata, sd_bus_error *ret_error) {
+        return 1;
+}
+
+static void destroy_callback(void *userdata) {
+        int *n_called = userdata;
+
+        (*n_called) ++;
+}
+
+static void test_destroy_callback(void) {
+        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+        sd_bus_slot *slot = NULL;
+        sd_bus_destroy_t t;
+
+        int r, n_called = 0;
+
+        log_info("/* %s */", __func__);
+
+        r = bus_open_system_watch_bind_with_description(&bus, "test-bus");
+        if (r < 0) {
+                log_error_errno(r, "Failed to connect to bus: %m");
+                return;
+        }
+
+        r = sd_bus_request_name_async(bus, &slot, "org.freedesktop.systemd.test-bus-util", 0, callback, &n_called);
+        assert(r == 1);
+
+        assert_se(sd_bus_slot_get_destroy_callback(slot, NULL) == 0);
+        assert_se(sd_bus_slot_get_destroy_callback(slot, &t) == 0);
+
+        assert_se(sd_bus_slot_set_destroy_callback(slot, destroy_callback) == 0);
+        assert_se(sd_bus_slot_get_destroy_callback(slot, NULL) == 1);
+        assert_se(sd_bus_slot_get_destroy_callback(slot, &t) == 1);
+        assert_se(t == destroy_callback);
+
+        /* Force cleanup so we can look at n_called */
+        assert(n_called == 0);
+        sd_bus_slot_unref(slot);
+        assert(n_called == 1);
+}
+
 int main(int argc, char **argv) {
         log_set_max_level(LOG_DEBUG);
         log_parse_environment();
@@ -42,6 +84,7 @@ int main(int argc, char **argv) {
 
         test_name_async(0);
         test_name_async(20);
+        test_destroy_callback();
 
         return 0;
 }