log command monitoring events on test failure

Author: kevinAlbs

src/libmongoc/tests/test-mongoc-bulk.c

@@ -4931,6 +4931,50 @@ test_bulk_let_multi (void)
    mock_server_destroy (mock_server);
 }
 
+
+static void
+bulk_write_multiple_errors_started_cb (
+   const mongoc_apm_command_started_t *event)
+{
+   bson_string_t *event_log = mongoc_apm_command_started_get_context (event);
+
+   bson_string_append_printf (
+      event_log,
+      "command %s started to %s: %s\n",
+      mongoc_apm_command_started_get_command_name (event),
+      mongoc_apm_command_started_get_host (event)->host_and_port,
+      tmp_json (mongoc_apm_command_started_get_command (event)));
+}
+
+static void
+bulk_write_multiple_errors_succeeded_cb (
+   const mongoc_apm_command_succeeded_t *event)
+{
+   bson_string_t *event_log = mongoc_apm_command_succeeded_get_context (event);
+
+   bson_string_append_printf (
+      event_log,
+      "command %s succeeded to %s in %" PRId64 "us: %s\n",
+      mongoc_apm_command_succeeded_get_command_name (event),
+      mongoc_apm_command_succeeded_get_host (event)->host_and_port,
+      mongoc_apm_command_succeeded_get_duration (event),
+      tmp_json (mongoc_apm_command_succeeded_get_reply (event)));
+}
+
+static void
+bulk_write_multiple_errors_failed_cb (const mongoc_apm_command_failed_t *event)
+{
+   bson_string_t *event_log = mongoc_apm_command_failed_get_context (event);
+
+   bson_string_append_printf (
+      event_log,
+      "command %s failed to %s in %" PRId64 "us: %s\n",
+      mongoc_apm_command_failed_get_command_name (event),
+      mongoc_apm_command_failed_get_host (event)->host_and_port,
+      mongoc_apm_command_failed_get_duration (event),
+      tmp_json (mongoc_apm_command_failed_get_reply (event)));
+}
+
 // Test a bulk write operation that receives two error replies from two
 // commands.
 static void
@@ -4944,10 +4988,19 @@ test_bulk_write_multiple_errors (void *unused)
    bson_t reply;
    bson_error_t error;
    bool r;
+   mongoc_apm_callbacks_t *cbs = mongoc_apm_callbacks_new ();
+   bson_string_t *event_log = bson_string_new (NULL);
 
    client = test_framework_new_default_client ();
    BSON_ASSERT (client);
 
+   mongoc_apm_set_command_started_cb (cbs,
+                                      bulk_write_multiple_errors_started_cb);
+   mongoc_apm_set_command_succeeded_cb (
+      cbs, bulk_write_multiple_errors_succeeded_cb);
+   mongoc_apm_set_command_failed_cb (cbs, bulk_write_multiple_errors_failed_cb);
+   mongoc_client_set_apm_callbacks (client, cbs, event_log);
+
    collection = get_test_collection (client, "test_bulk_write_multiple_errors");
    BSON_ASSERT (collection);
 
@@ -4983,14 +5036,21 @@ test_bulk_write_multiple_errors (void *unused)
    r = (bool) mongoc_bulk_operation_execute (bulk, &reply, &error);
    BSON_ASSERT (!r);
 
-   ASSERT_MATCH (&reply,
-                 "{'nInserted': 2,"
-                 " 'nMatched':  0,"
-                 " 'nModified': 0,"
-                 " 'nRemoved':  1,"
-                 " 'nUpserted': 0,"
-                 " 'errorReplies': [{'code': 8}, {'code': 8}],"
-                 " 'writeErrors': [{ 'index' : 5 }]}");
+   const char *pattern = "{'nInserted': 2,"
+                         " 'nMatched':  0,"
+                         " 'nModified': 0,"
+                         " 'nRemoved':  1,"
+                         " 'nUpserted': 0,"
+                         " 'errorReplies': [{'code': 8}, {'code': 8}],"
+                         " 'writeErrors': [{ 'index' : 5 }]}";
+
+   if (!match_json (&reply, false, __FILE__, __LINE__, BSON_FUNC, pattern)) {
+      // match_json prints the expected pattern and actual document.
+      // Print the command monitoring events to help diagnose the flaky test
+      // failure CDRIVER-4539.
+      test_error ("Got the following command monitoring events:\n%s",
+                  event_log->str);
+   }
 
    assert_write_error_count (1, &reply);
    ASSERT_COUNT (1, collection);
@@ -5000,6 +5060,8 @@ test_bulk_write_multiple_errors (void *unused)
    bson_destroy (&opts);
    mongoc_collection_destroy (collection);
    mongoc_client_destroy (client);
+   bson_string_free (event_log, true);
+   mongoc_apm_callbacks_destroy (cbs);
 }