Merge pull request #565 from GetStream/fix/channel-stop-watching

packages/stream_chat/lib/src/core/api/channel_api.dart

@@ -289,6 +289,7 @@ class ChannelApi {
   ) async {
     final response = await _client.post(
       '${_getChannelUrl(channelId, channelType)}/stop-watching',
+      data: {},
     );
     return EmptyResponse.fromJson(response.data);
   }

packages/stream_chat/test/src/core/api/channel_api_test.dart

@@ -595,14 +595,14 @@ void main() {
 
     final path = '${_getChannelUrl(channelId, channelType)}/stop-watching';
 
-    when(() => client.post(path)).thenAnswer(
+    when(() => client.post(path, data: {})).thenAnswer(
         (_) async => successResponse(path, data: <String, dynamic>{}));
 
     final res = await channelApi.stopWatching(channelId, channelType);
 
     expect(res, isNotNull);
 
-    verify(() => client.post(path)).called(1);
+    verify(() => client.post(path, data: {})).called(1);
     verifyNoMoreInteractions(client);
   });
 }