System.ArgumentNullException: Value cannot be null. (Parameter 'value') in .net Maui on Android when using WebSockets

[Laradius]

{System.ArgumentNullException: Value cannot be null. (Parameter 'value')
at GraphQL.Client.Http.Websocket.GraphQLHttpWebSocket.<>c__DisplayClass27_0`1[[ProgramClassHere, ProgramNameHere, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].b__3(Exception e) in /_/src/GraphQL.Client/Websocket/GraphQLHttpWebSocket.cs:line 211}

It happens when initializing websocket connection (either directly or by subscription stream).

The unhandled exception happens at line 402 of GraphQLHttpWebSocket.cs

_clientWebSocket.Options.ClientCertificates = ((HttpClientHandler)Options.HttpMessageHandler).ClientCertificates;

The error being thrown after execution of it at line 211 is due to X509CertificateCollection ArgumentNullException

if (!(e is WebSocketException)) throw e;

Error:

{System.ArgumentNullException: Value cannot be null. (Parameter 'value')
   at System.Net.WebSockets.ClientWebSocketOptions.set_ClientCertificates(X509CertificateCollection value)
   at GraphQL.Client.Http.Websocket.GraphQLHttpWebSocket.InitializeWebSocket() in [redacted]
   at GraphQL.Client.Http.Websocket.GraphQLHttpWebSocket.<>c__DisplayClass27_0`1.<<CreateSubscriptionStream>b__5>d[[-.Models.GraphQLModels.ResposeTypes.ProjectResponseType, -, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].MoveNext() in [redacted] src\GraphQL.Client\Websocket\GraphQLHttpWebSocket.cs:line 157}

It works fine on Windows, however it breaks on Android.

Will this client be compatible with .NET MAUI?

[sungam3r]

What is the type of _clientWebSocket and its options ?

[Laradius]

What is the type of _clientWebSocket and its options ?

By line 402 _clientWebSocket type is System.Net.WebSockets.ClientWebSocket and optinons type is System.Net.WebSockets.ClientWebSocketOptions

[sungam3r]

I asked about runtime values. On Windows I don't see null check in ClientWebSocketOptions.ClientCertificates.set. Maybe ClientWebSocketOptions instance on your platform is some inherited type.

[Laradius]

((HttpClientHandler)Options.HttpMessageHandler).ClientCertificates returns null

[Laradius]

I asked about runtime values. On Windows I don't see null check in ClientWebSocketOptions.ClientCertificates.set. Maybe ClientWebSocketOptions instance on your platform is some inherited type.

just commenting out the _clientWebSocket.Options.ClientCertificates = ((HttpClientHandler)Options.HttpMessageHandler).ClientCertificates; makes the library work, but I doubt it's the correct way

[sungam3r]

Ooops, I looked into wrong assembly. Sources:

 [UnsupportedOSPlatform("browser")]
        public X509CertificateCollection ClientCertificates
        {
            get => _clientCertificates ??= new X509CertificateCollection();
            set
            {
                ThrowIfReadOnly();
                _clientCertificates = value ?? throw new ArgumentNullException(nameof(value));
            }
        }

[Laradius]

@sungam3r Thanks a lot for fixing that issue 💯