api: Take stream or PM conversation as parameter in sendMessage

Author: gnprice

lib/api/route/messages.dart

@@ -92,26 +92,52 @@ const int kMaxMessageLengthCodePoints = 10000;
 const String kNoTopicTopic = '(no topic)';
 
 /// https://zulip.com/api/send-message
-// TODO currently only handles stream messages; fix
 Future<SendMessageResult> sendMessage(
   ApiConnection connection, {
+  required MessageDestination destination,
   required String content,
-  required String topic,
 }) {
-  // assert() is less verbose but would have no effect in production, I think:
-  //   https://dart.dev/guides/language/language-tour#assert
-  if (connection.realmUrl.origin != 'https://chat.zulip.org') {
-    throw Exception('This binding can currently only be used on https://chat.zulip.org.');
-  }
-
   return connection.post('sendMessage', SendMessageResult.fromJson, 'messages', {
-    'type': RawParameter('stream'), // TODO parametrize
-    'to': 7, // TODO parametrize; this is `#test here`
-    'topic': RawParameter(topic),
+    if (destination is StreamDestination) ...{
+      'type': RawParameter('stream'),
+      'to': destination.streamId,
+      'topic': RawParameter(destination.topic),
+    } else if (destination is PmDestination) ...{
+      'type': RawParameter('private'), // TODO(server-7)
+      'to': destination.userIds,
+    } else ...(
+      throw Exception('impossible destination') // TODO(dart-3) show this statically
+    ),
     'content': RawParameter(content),
   });
 }
 
+/// Which conversation to send a message to, in [sendMessage].
+///
+/// This is either a [StreamDestination] or a [PmDestination].
+sealed class MessageDestination {}
+
+/// A conversation in a stream, for specifying to [sendMessage].
+///
+/// The server accepts a stream name as an alternative to a stream ID,
+/// but this binding currently doesn't.
+class StreamDestination extends MessageDestination {
+  StreamDestination(this.streamId, this.topic);
+
+  final int streamId;
+  final String topic;
+}
+
+/// A PM conversation, for specifying to [sendMessage].
+///
+/// The server accepts a list of Zulip API emails as an alternative to
+/// a list of user IDs, but this binding currently doesn't.
+class PmDestination extends MessageDestination {
+  PmDestination({required this.userIds});
+
+  final List<int> userIds;
+}
+
 @JsonSerializable(fieldRename: FieldRename.snake)
 class SendMessageResult {
   final int id;

lib/model/store.dart

@@ -251,7 +251,13 @@ class PerAccountStore extends ChangeNotifier {
   Future<void> sendStreamMessage({required String topic, required String content}) {
     // TODO implement outbox; see design at
     //   https://chat.zulip.org/#narrow/stream/243-mobile-team/topic/.23M3881.20Sending.20outbox.20messages.20is.20fraught.20with.20issues/near/1405739
-    return sendMessage(connection, topic: topic, content: content);
+
+    if (connection.realmUrl.origin != 'https://chat.zulip.org') {
+      throw Exception('This method can currently only be used on https://chat.zulip.org.');
+    }
+    final destination = StreamDestination(7, topic); // TODO parametrize; this is `#test here`
+
+    return sendMessage(connection, destination: destination, content: content);
   }
 }
 

test/api/route/messages_test.dart

@@ -1,24 +1,52 @@
+import 'dart:convert';
+
 import 'package:checks/checks.dart';
+import 'package:http/http.dart' as http;
 import 'package:test/scaffolding.dart';
 import 'package:zulip/api/route/messages.dart';
 
+import '../../stdlib_checks.dart';
 import '../fake_api.dart';
 import 'route_checks.dart';
 
 void main() {
-  test('sendMessage accepts fixture realm', () async {
-    final connection = FakeApiConnection(
-      realmUrl: Uri.parse('https://chat.zulip.org/'));
-    connection.prepare(json: SendMessageResult(id: 42).toJson());
-    check(sendMessage(connection, content: 'hello', topic: 'world'))
-      .completes(it()..id.equals(42));
+  test('sendMessage to stream', () {
+    return FakeApiConnection.with_((connection) async {
+      const streamId = 123;
+      const topic = 'world';
+      const content = 'hello';
+      connection.prepare(json: SendMessageResult(id: 42).toJson());
+      final result = await sendMessage(connection,
+        destination: StreamDestination(streamId, topic), content: content);
+      check(result).id.equals(42);
+      check(connection.lastRequest).isNotNull().isA<http.Request>()
+        ..method.equals('POST')
+        ..url.path.equals('/api/v1/messages')
+        ..bodyFields.deepEquals({
+          'type': 'stream',
+          'to': streamId.toString(),
+          'topic': topic,
+          'content': content,
+        });
+    });
   });
 
-  test('sendMessage rejects unexpected realm', () async {
-    final connection = FakeApiConnection(
-      realmUrl: Uri.parse('https://chat.example/'));
-    connection.prepare(json: SendMessageResult(id: 42).toJson());
-    check(() => sendMessage(connection, content: 'hello', topic: 'world'))
-      .throws();
+  test('sendMessage to PM conversation', () {
+    return FakeApiConnection.with_((connection) async {
+      const userIds = [23, 34];
+      const content = 'hi there';
+      connection.prepare(json: SendMessageResult(id: 42).toJson());
+      final result = await sendMessage(connection,
+        destination: PmDestination(userIds: userIds), content: content);
+      check(result).id.equals(42);
+      check(connection.lastRequest).isNotNull().isA<http.Request>()
+        ..method.equals('POST')
+        ..url.path.equals('/api/v1/messages')
+        ..bodyFields.deepEquals({
+          'type': 'private',
+          'to': jsonEncode(userIds),
+          'content': content,
+        });
+    });
   });
 }