chore: Enable the unused_result_ok lint (#2333)

* chore: Enable the `unused_result_ok` lint

This also exposed an unneeded `Result` being returned from `stream_fairness`,
which this PR also removes.

* Restore error handling around `stream_fairness`

* Fix

* Remove old comment

---------

Signed-off-by: Lars Eggert <[email protected]>

Cargo.toml

@@ -72,6 +72,7 @@ renamed_function_params = "warn"
 semicolon_inside_block = "warn"
 try_err = "warn"
 unneeded_field_pattern = "warn"
+unused_result_ok = "warn"
 unused_trait_names = "warn"
 
 # Optimize build dependencies, because bindgen and proc macros / style

neqo-http3/src/connection.rs

@@ -737,8 +737,12 @@ impl Http3Connection {
                     conn.stream_stop_sending(stream_id, Error::HttpStreamCreation.code())?;
                     return Ok(ReceiveOutput::NoOutput);
                 }
-                // set incoming WebTransport streams to be fair (share bandwidth)
-                conn.stream_fairness(stream_id, true).ok();
+                // Set incoming WebTransport streams to be fair (share bandwidth).
+                // We may call this with an invalid stream ID, so ignore that error.
+                match conn.stream_fairness(stream_id, true) {
+                    Ok(()) | Err(neqo_transport::Error::InvalidStreamId) => (),
+                    Err(e) => return Err(Error::from(e)),
+                };
                 qinfo!(
                     [self],
                     "A new WebTransport stream {} for session {}.",
@@ -1283,8 +1287,7 @@ impl Http3Connection {
             .stream_create(stream_type)
             .map_err(|e| Error::map_stream_create_errors(&e))?;
         // Set outgoing WebTransport streams to be fair (share bandwidth)
-        // This really can't fail, panics if it does
-        conn.stream_fairness(stream_id, true).unwrap();
+        conn.stream_fairness(stream_id, true)?;
 
         self.webtransport_create_stream_internal(
             wt,

neqo-http3/src/connection_client.rs

@@ -812,10 +812,6 @@ impl Http3Client {
     /// # Errors
     ///
     /// It may return `InvalidStreamId` if a stream does not exist anymore.
-    ///
-    /// # Panics
-    ///
-    /// This cannot panic.
     pub fn webtransport_set_fairness(&mut self, stream_id: StreamId, fairness: bool) -> Res<()> {
         Http3Connection::stream_set_fairness(&mut self.conn, stream_id, fairness)
     }

neqo-transport/src/connection/mod.rs

@@ -1557,7 +1557,7 @@ impl Connection {
         );
         path.borrow_mut().add_received(d.len());
         let res = self.input_path(&path, d, received);
-        self.capture_error(Some(path), now, 0, res).ok();
+        _ = self.capture_error(Some(path), now, 0, res);
     }
 
     fn input_path(

neqo-transport/src/connection/tests/stream.rs

@@ -131,8 +131,8 @@ fn sendorder_test(order_of_sendorder: &[Option<SendOrder>]) {
         streams.push(id);
         ordered.push((id, *sendorder));
         // must be set before sendorder
-        client.streams.set_fairness(id, true).ok();
-        client.streams.set_sendorder(id, *sendorder).ok();
+        client.streams.set_fairness(id, true).unwrap();
+        client.streams.set_sendorder(id, *sendorder).unwrap();
     }
     // Write some data to all the streams
     for stream_id in streams {

neqo-transport/tests/connection.rs

@@ -283,8 +283,8 @@ fn handshake_mlkem768x25519() {
 
     client
         .set_groups(&[neqo_crypto::TLS_GRP_KEM_MLKEM768X25519])
-        .ok();
-    client.send_additional_key_shares(0).ok();
+        .unwrap();
+    client.send_additional_key_shares(0).unwrap();
 
     test_fixture::handshake(&mut client, &mut server);
     assert_eq!(*client.state(), State::Confirmed);