fix: tests::support::server

If the length of expected header is accidentally larger than the length
of the actual header, `socket.read()` will keep pulling bytes from the
socket which could no longer produce any, hence the later calls of
`socket.read` will return a `WouldBlock` Error.

tests/support/server.rs

@@ -51,7 +51,10 @@ pub fn spawn(txns: Vec<Txn>) -> Server {
 
             let mut n = 0;
             while n < expected.len() {
-                n += socket.read(&mut buf).unwrap();
+                match socket.read(&mut buf[n..]) {
+                    Ok(0) | Err(_) => break,
+                    Ok(nread) => n += nread,
+                }
             }
 
             match (::std::str::from_utf8(&expected), ::std::str::from_utf8(&buf[..n])) {