Ensure multiple shutdown attempts yield

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "stubborn-io"
-version = "0.3.2"
+version = "0.3.3"
 authors = ["David Raifaizen <david.raifaizen@protonmail.com>"]
 edition = "2021"
 description = "io traits/structs that automatically recover from potential disconnections/interruptions."

src/tokio/io.rs

@@ -95,12 +95,24 @@ enum Status<T, C> {
  FailedAndExhausted, // the way one feels after programming in dynamically typed languages
 }
 
+#[inline]
+fn poll_err<T>(
+ kind: ErrorKind,
+ reason: impl Into<Box<dyn std::error::Error + Send + Sync>>,
+) -> Poll<io::Result<T>> {
+ let io_err = io::Error::new(kind, reason);
+ Poll::Ready(Err(io_err))
+}
+
 fn exhausted_err<T>() -> Poll<io::Result<T>> {
- let io_err = io::Error::new(
+ poll_err(
  ErrorKind::NotConnected,
  "Disconnected. Connection attempts have been exhausted.",
- );
- Poll::Ready(Err(io_err))
+ )
+}
+
+fn disconnected_err<T>() -> Poll<io::Result<T>> {
+ poll_err(ErrorKind::NotConnected, "Underlying I/O is disconnected.")
 }
 
 impl<T, C> Deref for StubbornIo<T, C> {
@@ -381,7 +393,7 @@ where
 
  poll
  }
- Status::Disconnected(_) => Poll::Pending,
+ Status::Disconnected(_) => disconnected_err(),
  Status::FailedAndExhausted => exhausted_err(),
  }
  }

tests/integration_tests.rs

@@ -0,0 +1,28 @@
+use std::time::Duration;
+
+use stubborn_io::StubbornTcpStream;
+use tokio::{io::AsyncWriteExt, sync::oneshot};
+
+#[tokio::test]
+async fn back_to_back_shutdown_attempts() {
+ let (port_tx, port_rx) = oneshot::channel();
+ tokio::spawn(async move {
+ let mut streams = Vec::new();
+ let listener = tokio::net::TcpListener::bind("0.0.0.0:0").await.unwrap();
+ let addr = listener.local_addr().unwrap();
+ port_tx.send(addr).unwrap();
+ loop {
+ let (stream, _addr) = listener.accept().await.unwrap();
+ streams.push(stream);
+ }
+ });
+ let addr = port_rx.await.unwrap();
+ let mut connection = StubbornTcpStream::connect(addr).await.unwrap();
+
+ connection.shutdown().await.unwrap();
+ let elapsed = tokio::time::timeout(Duration::from_secs(5), connection.shutdown()).await;
+
+ let result = elapsed.unwrap();
+ let error = result.unwrap_err();
+ assert_eq!(error.kind(), std::io::ErrorKind::NotConnected);
+}