Factor out TestServer. (#98)

This creates a struct that encapsulates the test server setup, and adds
a shutdown method to clean up the thread when done.

src/test/timeout.rs

@@ -1,4 +1,5 @@
-use std::io::{self, BufRead, BufReader, Read, Write};
+use crate::test::testserver::*;
+use std::io::{self, Write};
 use std::net::TcpStream;
 use std::thread;
 use std::time::Duration;
@@ -7,7 +8,8 @@ use super::super::*;
 
 // Send an HTTP response on the TcpStream at a rate of two bytes every 10
 // milliseconds, for a total of 600 bytes.
-fn dribble_body_respond(stream: &mut TcpStream) -> io::Result<()> {
+fn dribble_body_respond(mut stream: TcpStream) -> io::Result<()> {
+    read_headers(&stream);
     let contents = [b'a'; 300];
     let headers = format!(
         "HTTP/1.1 200 OK\r\nContent-Length: {}\r\n\r\n",
@@ -23,49 +25,12 @@ fn dribble_body_respond(stream: &mut TcpStream) -> io::Result<()> {
     Ok(())
 }
 
-// Read a stream until reaching a blank line, in order to consume
-// request headers.
-fn read_headers(stream: &TcpStream) {
-    for line in BufReader::new(stream).lines() {
-        let line = match line {
-            Ok(x) => x,
-            Err(_) => return,
-        };
-        if line == "" {
-            break;
-        }
-    }
-}
-
-// Start a test server on an available port, that dribbles out a response at 1 write per 10ms.
-// Return the port this server is listening on.
-fn start_dribble_body_server() -> u16 {
-    let listener = std::net::TcpListener::bind("localhost:0").unwrap();
-    let port = listener.local_addr().unwrap().port();
-    let dribble_handler = |mut stream: TcpStream| {
-        read_headers(&stream);
-        if let Err(e) = dribble_body_respond(&mut stream) {
-            eprintln!("sending dribble repsonse: {}", e);
-        }
-    };
-    thread::spawn(move || {
-        for stream in listener.incoming() {
-            thread::spawn(move || dribble_handler(stream.unwrap()));
-        }
-    });
-    port
-}
-
 fn get_and_expect_timeout(url: String) {
     let agent = Agent::default().build();
     let timeout = Duration::from_millis(500);
     let resp = agent.get(&url).timeout(timeout).call();
 
-    let mut reader = resp.into_reader();
-    let mut bytes = vec![];
-    let result = reader.read_to_end(&mut bytes);
-
-    match result {
+    match resp.into_string() {
         Err(io_error) => match io_error.kind() {
             io::ErrorKind::WouldBlock => Ok(()),
             io::ErrorKind::TimedOut => Ok(()),
@@ -78,15 +43,15 @@ fn get_and_expect_timeout(url: String) {
 
 #[test]
 fn overall_timeout_during_body() {
-    let port = start_dribble_body_server();
-    let url = format!("http://localhost:{}/", port);
-
+    // Start a test server on an available port, that dribbles out a response at 1 write per 10ms.
+    let server = TestServer::new(dribble_body_respond);
+    let url = format!("http://localhost:{}/", server.port);
     get_and_expect_timeout(url);
 }
 
 // Send HTTP headers on the TcpStream at a rate of one header every 100
 // milliseconds, for a total of 30 headers.
-fn dribble_headers_respond(stream: &mut TcpStream) -> io::Result<()> {
+fn dribble_headers_respond(mut stream: TcpStream) -> io::Result<()> {
     stream.write_all(b"HTTP/1.1 200 OK\r\nContent-Length: 0\r\n")?;
     for _ in 0..30 {
         stream.write_all(b"a: b\n")?;
@@ -96,28 +61,10 @@ fn dribble_headers_respond(stream: &mut TcpStream) -> io::Result<()> {
     Ok(())
 }
 
-// Start a test server on an available port, that dribbles out response *headers* at 1 write per 10ms.
-// Return the port this server is listening on.
-fn start_dribble_headers_server() -> u16 {
-    let listener = std::net::TcpListener::bind("localhost:0").unwrap();
-    let port = listener.local_addr().unwrap().port();
-    let dribble_handler = |mut stream: TcpStream| {
-        read_headers(&stream);
-        if let Err(e) = dribble_headers_respond(&mut stream) {
-            eprintln!("sending dribble repsonse: {}", e);
-        }
-    };
-    thread::spawn(move || {
-        for stream in listener.incoming() {
-            thread::spawn(move || dribble_handler(stream.unwrap()));
-        }
-    });
-    port
-}
-
 #[test]
 fn overall_timeout_during_headers() {
-    let port = start_dribble_headers_server();
-    let url = format!("http://localhost:{}/", port);
+    // Start a test server on an available port, that dribbles out a response at 1 write per 10ms.
+    let server = TestServer::new(dribble_headers_respond);
+    let url = format!("http://localhost:{}/", server.port);
     get_and_expect_timeout(url);
 }