write server test (#19)

tests/server.rs

@@ -0,0 +1,110 @@
+use mini_redis::server;
+
+use std::net::SocketAddr;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::{TcpListener, TcpStream};
+use tokio::task::JoinHandle;
+use tokio::time::{self, Duration};
+
+/// A basic "hello world" style test. A server instance is started in a
+/// background task. A client TCP connection is then established and raw redis
+/// commands are sent to the server. The response is evaluated at the byte
+/// level.
+#[tokio::test]
+async fn key_value_get_set() {
+    let (addr, _handle) = start_server().await;
+
+    // Establish a connection to the server
+    let mut stream = TcpStream::connect(addr).await.unwrap();
+
+    // Get a key, data is missing
+    stream.write_all(b"*2\r\n$3\r\nGET\r\n$5\r\nhello\r\n").await.unwrap();
+
+    // Read nil response
+    let mut response = [0; 5];
+
+    stream.read_exact(&mut response).await.unwrap();
+
+    assert_eq!(b"$-1\r\n", &response);
+
+    // Set a key
+    stream.write_all(b"*3\r\n$3\r\nSET\r\n$5\r\nhello\r\n$5\r\nworld\r\n").await.unwrap();
+
+    // Read OK
+    stream.read_exact(&mut response).await.unwrap();
+
+    assert_eq!(b"+OK\r\n", &response);
+
+    // Get the key, data is present
+    stream.write_all(b"*2\r\n$3\r\nGET\r\n$5\r\nhello\r\n").await.unwrap();
+
+    // Read "world" response
+    let mut response = [0; 11];
+
+    stream.read_exact(&mut response).await.unwrap();
+
+    assert_eq!(b"$5\r\nworld\r\n", &response);
+}
+
+/// Similar to the basic key-value test, however, this time timeouts will be
+/// tested. This test demonstrates how to test time related behavior.
+///
+/// When writing tests, it is useful to remove sources of non-determinism. Time
+/// is a source of non-determinism. Here, we "pause" time using the
+/// `time::pause()` function. This function is available with the `test-util`
+/// feature flag. This allows us to deterministically control how time appears
+/// to advance to the application.
+#[tokio::test]
+async fn key_value_timeout() {
+    tokio::time::pause();
+
+    let (addr, _handle) = start_server().await;
+
+    // Establish a connection to the server
+    let mut stream = TcpStream::connect(addr).await.unwrap();
+
+    // Set a key
+    stream.write_all(b"*5\r\n$3\r\nSET\r\n$5\r\nhello\r\n$5\r\nworld\r\n\
+                     +EX\r\n:1\r\n").await.unwrap();
+
+    let mut response = [0; 5];
+
+    // Read OK
+    stream.read_exact(&mut response).await.unwrap();
+
+    assert_eq!(b"+OK\r\n", &response);
+
+    // Get the key, data is present
+    stream.write_all(b"*2\r\n$3\r\nGET\r\n$5\r\nhello\r\n").await.unwrap();
+
+    // Read "world" response
+    let mut response = [0; 11];
+
+    stream.read_exact(&mut response).await.unwrap();
+
+    assert_eq!(b"$5\r\nworld\r\n", &response);
+
+    // Wait for the key to expire
+    time::advance(Duration::from_secs(1)).await;
+
+    // Get a key, data is missing
+    stream.write_all(b"*2\r\n$3\r\nGET\r\n$5\r\nhello\r\n").await.unwrap();
+
+    // Read nil response
+    let mut response = [0; 5];
+
+    stream.read_exact(&mut response).await.unwrap();
+
+    assert_eq!(b"$-1\r\n", &response);
+}
+
+async fn start_server() -> (SocketAddr, JoinHandle<mini_redis::Result<()>>) {
+    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let addr = listener.local_addr().unwrap();
+
+    let handle = tokio::spawn(async move {
+        server::run(listener, tokio::signal::ctrl_c()).await
+    });
+
+    (addr, handle)
+}