add integration tests for TcpStream::connect (#99)

Author: metent

examples/tcp_stream_client.rs

@@ -0,0 +1,25 @@
+use wstd::io::{self, AsyncRead, AsyncWrite};
+use wstd::net::TcpStream;
+
+#[wstd::main]
+async fn main() -> io::Result<()> {
+    let mut args = std::env::args();
+
+    let _ = args.next();
+
+    let addr = args.next().ok_or_else(|| {
+        io::Error::new(
+            std::io::ErrorKind::InvalidInput,
+            "address argument required",
+        )
+    })?;
+
+    let mut stream = TcpStream::connect(addr).await?;
+
+    stream.write_all(b"ping\n").await?;
+
+    let mut reply = Vec::new();
+    stream.read_to_end(&mut reply).await?;
+
+    Ok(())
+}

test-programs/tests/tcp_stream_client.rs

@@ -0,0 +1,53 @@
+use anyhow::{Context, Result};
+use std::net::{Shutdown, TcpListener};
+use std::process::{Command, Stdio};
+
+#[test_log::test]
+fn tcp_stream_client() -> Result<()> {
+    use std::io::{Read, Write};
+
+    let server = TcpListener::bind("127.0.0.1:8082").context("binding temporary test server")?;
+    let addr = server
+        .local_addr()
+        .context("getting local listener address")?;
+
+    let child = Command::new("wasmtime")
+        .arg("run")
+        .arg("-Sinherit-network")
+        .arg(test_programs::TCP_STREAM_CLIENT)
+        .arg(addr.to_string())
+        .stdout(Stdio::piped())
+        .spawn()
+        .context("spawning wasmtime component")?;
+
+    let (mut server_stream, _addr) = server
+        .accept()
+        .context("accepting TCP connection from component")?;
+
+    let mut buf = [0u8; 5];
+    server_stream
+        .read_exact(&mut buf)
+        .context("reading ping message")?;
+    assert_eq!(&buf, b"ping\n", "expected ping from component");
+
+    server_stream
+        .write_all(b"pong\n")
+        .context("writing reply")?;
+    server_stream.flush().context("flushing")?;
+
+    server_stream
+        .shutdown(Shutdown::Both)
+        .context("shutting down connection")?;
+
+    let output = child
+        .wait_with_output()
+        .context("waiting for component exit")?;
+
+    assert!(
+        output.status.success(),
+        "\nComponent exited abnormally (stderr:\n{})",
+        String::from_utf8_lossy(&output.stderr)
+    );
+
+    Ok(())
+}