Improve accounts_balances RPC (#4228)

nano/node/json_handler.cpp

@@ -898,6 +898,7 @@ void nano::json_handler::account_weight ()
 void nano::json_handler::accounts_balances ()
 {
 	boost::property_tree::ptree balances;
+	boost::property_tree::ptree errors;
 	auto transaction = node.store.tx_begin_read ();
 	for (auto & account_from_request : request.get_child ("accounts"))
 	{
@@ -913,11 +914,18 @@ void nano::json_handler::accounts_balances ()
 			balances.put_child (account_from_request.second.data (), entry);
 			continue;
 		}
-		entry.put ("error", ec.message ());
+		debug_assert (ec);
-		balances.put_child (account_from_request.second.data (), entry);
+		errors.put (account_from_request.second.data (), ec.message ());
 		ec = {};
 	}
-	response_l.add_child ("balances", balances);
+	if (!balances.empty ())
+	{
+		response_l.add_child ("balances", balances);
+	}
+	if (!errors.empty ())
+	{
+		response_l.add_child ("errors", errors);
+	}
 	response_errors ();
 }
 

nano/rpc_test/rpc.cpp

@@ -2902,17 +2902,11 @@ TEST (rpc, accounts_balances)
 	entry1.put ("", nano::dev::genesis_key.pub.to_account ());
 	accounts_l.push_back (std::make_pair ("", entry1));
 
-	// Adds a bad account string for getting an error response (the nano_ address checksum is wrong)
-	boost::property_tree::ptree entry2;
-	auto const bad_account_number = "nano_3e3j5tkog48pnny9dmfzj1r16pg8t1e76dz5tmac6iq689wyjfpiij4txtd1";
-	entry2.put ("", bad_account_number);
-	accounts_l.push_back (std::make_pair ("", entry2));
-
 	// Adds a valid account string that isn't on the ledger for getting an error response.
-	boost::property_tree::ptree entry3;
+	boost::property_tree::ptree entry2;
 	auto const account_not_found = "nano_1os6txqxyuesnxrtshnfb5or1hesc1647wpk9rsr84pmki6eairwha79hk3j";
-	entry3.put ("", account_not_found);
+	entry2.put ("", account_not_found);
-	accounts_l.push_back (std::make_pair ("", entry3));
+	accounts_l.push_back (std::make_pair ("", entry2));
 
 	request.add_child ("accounts", accounts_l);
 	auto response (wait_response (system, rpc_ctx, request));
@@ -2924,11 +2918,6 @@ TEST (rpc, accounts_balances)
 	auto receivable_text = genesis_entry.get<std::string> ("receivable");
 	ASSERT_EQ ("0", receivable_text);
 
-	auto get_error_message = [] (nano::error_common error_common) -> std::string {
-		std::error_code ec = error_common;
-		return ec.message ();
-	};
-
 	// Checking the account not found response - we do not distinguish between account not found and zero balance, zero receivables
 	auto account_not_found_entry = response.get_child (boost::str (boost::format ("balances.%1%") % account_not_found));
 	auto account_balance_text = account_not_found_entry.get<std::string> ("balance");
@@ -2936,10 +2925,49 @@ TEST (rpc, accounts_balances)
 	auto account_receivable_text = account_not_found_entry.get<std::string> ("receivable");
 	ASSERT_EQ ("0", account_receivable_text);
 
+	auto balances = response.get_child ("balances");
+	ASSERT_EQ (2, balances.size ());
+
+	auto errors = response.get_child_optional ("errors");
+	ASSERT_FALSE (errors.has_value ());
+}
+
+/**
+ * Test the RPC accounts_balances with 3 accounts, one good one, one with an invalid account ID and one with
+ * an account that does not exist.
+ */
+TEST (rpc, accounts_balances_with_errors)
+{
+	nano::test::system system;
+	auto node = add_ipc_enabled_node (system);
+	auto const rpc_ctx = add_rpc (system, node);
+	boost::property_tree::ptree request;
+	request.put ("action", "accounts_balances");
+	boost::property_tree::ptree accounts_l;
+
+	// Adds a bad account string for getting an error response (the nano_ address checksum is wrong)
+	boost::property_tree::ptree entry;
+	auto const bad_account_number = "nano_3e3j5tkog48pnny9dmfzj1r16pg8t1e76dz5tmac6iq689wyjfpiij4txtd1";
+	entry.put ("", bad_account_number);
+	accounts_l.push_back (std::make_pair ("", entry));
+
+	request.add_child ("accounts", accounts_l);
+	auto response (wait_response (system, rpc_ctx, request));
+
+	auto balances = response.get_child_optional ("balances");
+	ASSERT_FALSE (balances.has_value ());
+
+	auto get_error_message = [] (nano::error_common error_common) -> std::string {
+		std::error_code ec = error_common;
+		return ec.message ();
+	};
+
 	// Checking the bad account number response
-	auto bad_account_number_entry = response.get_child (boost::str (boost::format ("balances.%1%") % bad_account_number));
+	auto errors = response.get_child ("errors");
-	auto error_text2 = bad_account_number_entry.get<std::string> ("error");
+	ASSERT_EQ (1, errors.size ());
-	ASSERT_EQ (get_error_message (nano::error_common::bad_account_number), error_text2);
+	ASSERT_EQ (1, errors.count (bad_account_number));
+	auto bad_account_number_error_text = errors.get<std::string> (bad_account_number);
+	ASSERT_EQ (get_error_message (nano::error_common::bad_account_number), bad_account_number_error_text);
 }
 
 /**