Mock server¶

MockRhpServer is a real, in-process TCP server that speaks RHPv2. It ships in the same NuGet package as the client (under RhpV2.Client.Testing) so downstream consumers can write integration tests with no extra infrastructure.

The same code backs the rhp serve command.

When to reach for it¶

Unit tests that want to exercise RhpClient's framing and event pipeline against a real socket.
Higher-level application tests that need a deterministic peer.
Local development of a tool when you don't want to key up a radio.

When not to reach for it¶

Anything where realistic radio behaviour matters: link timing, paclen, REJ/SREJ recovery, NetRom routing, congestion.

Construction¶

await using var server = new MockRhpServer();    // ephemeral port
server.Start();                                  // begin accepting

await using var server2 = new MockRhpServer(port: 19000);
server2.Start();

Console.WriteLine($"Mock listening on {server.Endpoint}");

Endpoint is an IPEndPoint, so server.Endpoint.Port is the port your test client should connect to.

Default behaviour¶

The mock implements just enough of the spec to let RhpClient exercise its full lifecycle:

Incoming frame	Default reply
`auth`	`authReply` ok (or 14 if credentials don't match `Credentials`).
`open`	`openReply` with a fresh handle.
`socket`	`socketReply` with a fresh handle.
`bind` / `listen` / `connect` / `close`	matching `*Reply` ok if handle is known.
`send`	`sendReply` ok if handle is known.
`sendto`	`sendtoReply` ok if handle is known.
`status` (request)	server-pushed `status` with `Connected` flag.

Unknown handles produce errcode=3 (Invalid handle) replies.

Hooks¶

Require auth¶

await using var server = new MockRhpServer
{
    RequireAuth = true,
    Credentials = ("g8pzt", "secret"),
};
server.Start();

Custom replies¶

Override the default behaviour by setting a Handler delegate. Return null to defer to the default; return a message to override.

server.Handler = msg => msg switch
{
    OpenMessage o when o.Pfam == "netrom" =>
        new OpenReplyMessage { ErrCode = RhpErrorCode.NoSuchPort, ErrText = "No such port" },
    _ => null,
};

Push notifications to all clients¶

await server.BroadcastAsync(new RecvMessage
{
    Handle = 100,
    Data = "PING\r",
});

BroadcastAsync auto-assigns seqno if you omit it.

Suppress all replies (test timeouts)¶

var server = new MockRhpServer { SuppressReplies = true };

The mock still reads incoming frames into ReceivedFrames but never writes a reply — handy for testing client-side timeout / disconnect handling.

Asserting on what the client sent¶

Every received frame lands in server.ReceivedFrames (a ConcurrentQueue<RhpMessage>). Tests can dequeue it and inspect:

await client.OpenAsync(...);

var frame = (OpenMessage)server.ReceivedFrames.Single();
Assert.Equal("ax25", frame.Pfam);
Assert.Equal((int)OpenFlags.Active, frame.Flags);

Disposal¶

MockRhpServer is IAsyncDisposable. Disposal:

Stops the TCP listener.
Cancels the accept loop.
Disconnects any active sessions.

Connected RhpClients see the disconnection, fault their pending requests with RhpTransportException, and raise Disconnected.