It's almost like real tests.

clients/c/test.c

@@ -1,3 +1,4 @@
+#include <assert.h>
 #include <unistd.h>
 
 #include "cosmopolite.h"
@@ -9,8 +10,28 @@
 #define ANSI_COLOR_YELLOW  "\x1b[33m"
 #define ANSI_COLOR_RESET   "\x1b[0m"
 
+pthread_mutex_t message_lock;
+pthread_cond_t message_cond;
+const json_t *last_message;
+
 void on_message(const json_t *message, void *passthrough) {
-  printf("new message: %lld\n", json_integer_value(json_object_get(message, "id")));
+  assert(!pthread_mutex_lock(&message_lock));
+  assert(!last_message);
+  last_message = message;
+  assert(!pthread_cond_signal(&message_cond));
+  assert(!pthread_mutex_unlock(&message_lock));
+}
+
+const json_t *wait_for_message() {
+  assert(!pthread_mutex_lock(&message_lock));
+  if (!last_message) {
+    assert(!pthread_cond_wait(&message_cond, &message_lock));
+  }
+
+  const json_t *ret = last_message;
+  last_message = NULL;
+  assert(!pthread_mutex_unlock(&message_lock));
+  return ret;
 }
 
 cosmo *create_client() {
@@ -32,6 +53,12 @@ json_t *random_subject(const char *readable_only_by, const char *writeable_only_
   return cosmo_subject(name, readable_only_by, writeable_only_by);
 }
 
+json_t *random_message() {
+  char uuid[COSMO_UUID_SIZE];
+  cosmo_uuid(uuid);
+  return json_string(uuid);
+}
+
 void run_test(const char *func_name, bool (*test)(void)) {
   fprintf(stderr, ANSI_COLOR_YELLOW "%50s" ANSI_COLOR_RESET ": ", func_name);
   if (test()) {
@@ -47,19 +74,32 @@ bool test_create_destroy() {
   return true;
 }
 
-bool message_round_trip() {
+bool test_message_round_trip() {
   cosmo *client = create_client();
 
   json_t *subject = random_subject(NULL, NULL);
   cosmo_subscribe(client, subject, -1, 0);
 
+  json_t *message_out = random_message();
+  cosmo_send_message(client, subject, message_out);
+  const json_t *message_in = wait_for_message();
+  assert(json_equal(message_out, json_object_get(message_in, "message")));
+
   json_decref(subject);
+  json_decref(message_out);
   cosmo_shutdown(client);
   return true;
 }
 
 int main(int argc, char *argv[]) {
+  assert(!pthread_mutex_init(&message_lock, NULL));
+  assert(!pthread_cond_init(&message_cond, NULL));
+
   RUN_TEST(test_create_destroy);
-  RUN_TEST(message_round_trip);
+  RUN_TEST(test_message_round_trip);
+
+  assert(!pthread_cond_destroy(&message_cond));
+  assert(!pthread_mutex_destroy(&message_lock));
+
   return 0;
 }