homework: reduce panics

smart-house/src/bin/power_socket_client.rs

@@ -1,10 +1,11 @@
 use smart_house::PowerSocket;
 use std::time::Duration;
 
-fn main() {
+fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let mut power_socket = PowerSocket::connect("127.0.0.1:10001");
+    let mut power_socket = PowerSocket::connect("127.0.0.1:10001")?;
     println!("{}", power_socket.display());
     std::thread::sleep(Duration::from_secs(2));
     power_socket.set_on(!power_socket.is_on());
     println!("{}", power_socket.display());
+    Ok(())
 }

smart-house/src/power_socket.rs

@@ -1,5 +1,6 @@
 use std::cell::RefCell;
 use std::fmt::{Debug, Display};
+use std::io;
 use std::io::{Read, Write};
 use std::net::{SocketAddr, TcpStream};
 use std::time::Duration;
@@ -16,10 +17,9 @@ impl PowerSocket {
         }
     }
 
-    pub fn connect(addr: &str) -> Self {
+    pub fn connect(addr: &str) -> Result<Self, io::Error> {
-        Self {
+        let handle = PowerSocketClient::new(addr)?;
-            handle: Box::new(PowerSocketClient::new(addr)),
+        Ok(Self { handle: Box::new(handle) })
-        }
     }
 
     pub fn is_on(&self) -> bool {
@@ -82,12 +82,12 @@ struct PowerSocketClient {
 }
 
 impl PowerSocketClient {
-    pub fn new(addr: &str) -> Self {
+    fn new(addr: &str) -> Result<Self, io::Error> {
-        let addr: SocketAddr = addr.parse().expect("addr should be valid tcp address");
+        let addr: SocketAddr = addr.parse().map_err(io::Error::other)?;
-        let stream = TcpStream::connect_timeout(&addr, TIMEOUT).expect("address should be available to connect");
+        let stream = TcpStream::connect_timeout(&addr, TIMEOUT)?;
-        stream.set_write_timeout(Some(TIMEOUT)).expect("write timeout should be set");
+        stream.set_write_timeout(Some(TIMEOUT))?;
-        stream.set_read_timeout(Some(TIMEOUT)).expect("read timeout should be set");
+        stream.set_read_timeout(Some(TIMEOUT))?;
-        Self { stream: RefCell::new(stream) }
+        Ok(Self { stream: RefCell::new(stream) })
     }
 }