feat(rpc): throw exception when cln returns an error

Author: swaptr

melos.yaml

@@ -13,7 +13,7 @@ scripts:
     select-package:
 
   rpc_analyze:
-    run: melos exec -c 1 --scope="rpc" -- "dart format --set-exit-if-changed . && dart analyze . --fatal-infos"
+    run: melos exec -c 1 --scope="clightning_rpc" -- "dart format --set-exit-if-changed . && dart analyze . --fatal-infos"
     description: Run dart analyzer in a specific package.
 
   plugin_analyze:
@@ -48,7 +48,7 @@ scripts:
 
   rpc_test:
     description: Run tests in a specific package.
-    run: melos exec --concurrency=2 --scope="rpc" -- "dart pub get && dart pub run test"
+    run: melos exec --concurrency=2 --scope="clightning_rpc" -- "dart pub get && dart pub run test"
     env:
       MELOS_TEST: true
 

packages/rpc/lib/src/clightning_rpc.dart

@@ -22,7 +22,9 @@ class RPCClient implements LightningClient {
   }
 
   @override
-  void close() async {}
+  void close() async {
+    return;
+  }
 
   @override
   Future<T> call<R extends Serializable, T>(

packages/rpc/lib/src/utils/exception/ln_client_error.dart

@@ -0,0 +1,7 @@
+class LNClientException implements Exception {
+  String message;
+  int code;
+  String? data;
+
+  LNClientException(this.code, this.message, this.data);
+}

packages/rpc/lib/src/utils/unix_rpc_client.dart

@@ -4,6 +4,7 @@ import 'dart:io';
 
 import 'package:cln_common/cln_common.dart';
 import 'package:jsonrpc2/jsonrpc2.dart';
+import 'exception/ln_client_error.dart';
 
 class UnixRPCClient extends ServerProxyBase {
   UnixRPCClient(String path) : super(path);
@@ -17,12 +18,25 @@ class UnixRPCClient extends ServerProxyBase {
     var socket = await Socket.connect(address, 0);
     socket.add(utf8.encode(package));
 
-    socket.listen((event) {
-      LogManager.getInstance.debug('Event received is ${utf8.decode(event)}');
-      completer.complete(utf8.decode(event));
-    },
+    socket.listen(
+        (event) {
+          LogManager.getInstance
+              .debug('Event received is ${utf8.decode(event)}');
+          Map<String, dynamic> eventMap = jsonDecode(utf8.decode(event));
+          if (eventMap.containsKey("error")) {
+            var error = eventMap["error"];
+            var exception = LNClientException(
+                error["code"], error["message"], error["data"]);
+            completer.completeError(exception);
+          } else {
+            completer.complete(utf8.decode(event));
+          }
+        },
         onDone: () => LogManager.getInstance.debug('End JSON RPC Stream'),
-        onError: (err) => LogManager.getInstance.error(err));
+        onError: (error) {
+          LogManager.getInstance.error(error);
+          completer.completeError(error);
+        });
     return completer.future;
   }
 }

packages/rpc/test/clightning_rpc_test.dart

@@ -1,34 +1,28 @@
 import 'dart:io';
 import 'package:test/test.dart';
 import 'package:clightning_rpc/clightning_rpc.dart';
+import 'package:clightning_rpc/src/utils/exception/ln_client_error.dart';
 
 void main() {
   var env = Platform.environment;
   var rpcPath = env['RPC_PATH']!;
+
   group('A group of test to connect the unix socket', () {
-    setUp(() {});
+    var client = RPCClient();
+    client.connect(rpcPath);
 
-    test('Connection test', () {
-      var client = RPCClient();
-      client.connect(rpcPath);
-      expect(client, isNotNull);
-      client.close();
-    });
+    setUp(() {});
 
     test('Call getinfo method test', () async {
-      var client = RPCClient();
-      client.connect(rpcPath);
       expect(client, isNotNull);
       var response = await client.simpleCall('getinfo');
       expect(response['network'], 'regtest');
       client.close();
     });
 
-    test('Call invoice method test', () async {
-      var client = RPCClient();
-      client.connect(rpcPath);
+    test('Make a loop payment and looking for exception', () async {
       expect(client, isNotNull);
-      // Docs of the parametes
+      // Docs of the parameters
       // https://lightning.readthedocs.io/lightning-invoice.7.html
       var params = <String, dynamic>{};
       params['msatoshi'] = '100000msat';
@@ -43,5 +37,27 @@ void main() {
       await client.simpleCall('delinvoice', params: params);
       client.close();
     });
+
+    test('Pay invoice method test', () async {
+      expect(client, isNotNull);
+
+      var params = <String, dynamic>{};
+      params['msatoshi'] = '100000msat';
+      params['label'] = 'from-dart-v2';
+      params['description'] = 'This is a unit test';
+
+      var response = await client.simpleCall('invoice', params: params);
+      params = <String, dynamic>{};
+      params['bolt11'] = response["bolt11"];
+
+      expect(() async => await client.simpleCall('pay', params: params),
+          throwsA(isA<LNClientException>()));
+
+      params = <String, dynamic>{};
+      params['label'] = 'from-dart-v2';
+      params['status'] = 'unpaid';
+      await client.simpleCall('delinvoice', params: params);
+      client.close();
+    });
   });
 }