fix(tonic): Remove Sync requirement for streams (#804)

tests/integration_tests/src/lib.rs

@@ -2,3 +2,54 @@ pub mod pb {
     tonic::include_proto!("test");
     tonic::include_proto!("stream");
 }
+
+pub mod mock {
+    use std::{
+        pin::Pin,
+        task::{Context, Poll},
+    };
+
+    use tokio::io::{AsyncRead, AsyncWrite, ReadBuf};
+    use tonic::transport::server::Connected;
+
+    #[derive(Debug)]
+    pub struct MockStream(pub tokio::io::DuplexStream);
+
+    impl Connected for MockStream {
+        type ConnectInfo = ();
+
+        /// Create type holding information about the connection.
+        fn connect_info(&self) -> Self::ConnectInfo {}
+    }
+
+    impl AsyncRead for MockStream {
+        fn poll_read(
+            mut self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            buf: &mut ReadBuf<'_>,
+        ) -> Poll<std::io::Result<()>> {
+            Pin::new(&mut self.0).poll_read(cx, buf)
+        }
+    }
+
+    impl AsyncWrite for MockStream {
+        fn poll_write(
+            mut self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+            buf: &[u8],
+        ) -> Poll<std::io::Result<usize>> {
+            Pin::new(&mut self.0).poll_write(cx, buf)
+        }
+
+        fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<std::io::Result<()>> {
+            Pin::new(&mut self.0).poll_flush(cx)
+        }
+
+        fn poll_shutdown(
+            mut self: Pin<&mut Self>,
+            cx: &mut Context<'_>,
+        ) -> Poll<std::io::Result<()>> {
+            Pin::new(&mut self.0).poll_shutdown(cx)
+        }
+    }
+}