Start to write e2e tests

src/test/dummy_tcp_sockets.rs

@@ -0,0 +1,250 @@
+use std::time::Duration;
+
+use rand::Rng;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::{TcpListener, TcpStream};
+use tokio::time;
+
+use crate::test::LOCALHOST;
+
+pub struct DummyTCPServer(TcpListener);
+
+impl DummyTCPServer {
+    pub async fn start(port: u16) -> Self {
+        let addr = format!("{}:{}", LOCALHOST, port);
+        println!("[DUMMY TCP] Listen on {}", addr);
+        let listener = TcpListener::bind(addr)
+            .await
+            .expect("Failed to bind dummy TCP listener!");
+        Self(listener)
+    }
+
+    /// Receive chunk of data from following connection
+    pub async fn read_next_connection(&self) -> Vec<u8> {
+        let (mut conn, _addr) = self
+            .0
+            .accept()
+            .await
+            .expect("Could not open next connection!");
+
+        let mut buff = Vec::with_capacity(100);
+        conn.read_to_end(&mut buff).await.unwrap();
+
+        buff
+    }
+
+    /// Receive chunk of data from following connection
+    pub async fn read_then_write_next_connection(&self, to_send: &[u8]) -> Vec<u8> {
+        let (mut conn, _addr) = self
+            .0
+            .accept()
+            .await
+            .expect("Could not open next connection!");
+
+        let mut buff: [u8; 100] = [0; 100];
+        let size = conn.read(&mut buff).await.unwrap();
+
+        conn.write_all(to_send).await.unwrap();
+
+        buff[0..size].to_vec()
+    }
+
+    /// Receive chunk of data from following connection
+    pub async fn write_next_connection(&self, to_send: &[u8]) {
+        let (mut conn, _addr) = self
+            .0
+            .accept()
+            .await
+            .expect("Could not open next connection!");
+
+        conn.write_all(to_send).await.unwrap()
+    }
+
+    /// Perform complex exchange: receive numbers from client and respond with their square
+    pub async fn next_conn_square_operations(&self) {
+        let (mut conn, _addr) = self
+            .0
+            .accept()
+            .await
+            .expect("Could not open next connection!");
+
+        let mut buff: [u8; 100] = [0; 100];
+        loop {
+            let size = conn.read(&mut buff).await.unwrap();
+            if size == 0 {
+                break;
+            }
+
+            let content = String::from_utf8_lossy(&buff[0..size])
+                .to_string()
+                .parse::<i64>()
+                .unwrap();
+
+            conn.write_all((content * content).to_string().as_bytes())
+                .await
+                .unwrap();
+        }
+    }
+}
+
+pub async fn dummy_tcp_client_read_conn(port: u16) -> Vec<u8> {
+    let mut socket = TcpStream::connect(format!("127.0.0.1:{}", port))
+        .await
+        .expect("Failed to connect to dummy TCP server!");
+
+    let mut buff = Vec::with_capacity(100);
+    socket.read_to_end(&mut buff).await.unwrap();
+
+    buff
+}
+
+pub async fn dummy_tcp_client_write_then_read_conn(port: u16, data: &[u8]) -> Vec<u8> {
+    let mut socket = TcpStream::connect(format!("127.0.0.1:{}", port))
+        .await
+        .expect("Failed to connect to dummy TCP server!");
+
+    socket.write_all(data).await.unwrap();
+
+    let mut buff: [u8; 100] = [0; 100];
+    let size = socket.read(&mut buff).await.unwrap();
+
+    buff[0..size].to_vec()
+}
+
+pub async fn dummy_tcp_client_write_conn(port: u16, data: &[u8]) {
+    let mut socket = TcpStream::connect(format!("127.0.0.1:{}", port))
+        .await
+        .expect("Failed to connect to dummy TCP server!");
+
+    socket.write_all(data).await.unwrap()
+}
+
+pub async fn dummy_tcp_client_square_root_requests(port: u16, num_exchanges: usize) {
+    let mut socket = TcpStream::connect(format!("127.0.0.1:{}", port))
+        .await
+        .expect("Failed to connect to dummy TCP server!");
+
+    let mut rng = rand::thread_rng();
+    let mut buff: [u8; 100] = [0; 100];
+
+    for _ in 0..num_exchanges {
+        let num = rng.gen::<i32>() % 100;
+        socket.write_all(num.to_string().as_bytes()).await.unwrap();
+
+        let size = socket.read(&mut buff).await.unwrap();
+
+        if size == 0 {
+            panic!("Got empty response!");
+        }
+
+        let got = String::from_utf8_lossy(&buff[0..size])
+            .to_string()
+            .parse::<i64>()
+            .unwrap();
+        println!("{} * {} = {} (based on server response)", num, num, got);
+        assert_eq!((num * num) as i64, got);
+    }
+}
+
+/// Check whether a given port is open or not
+pub async fn is_port_open(port: u16) -> bool {
+    match TcpStream::connect(("127.0.0.1", port)).await {
+        Ok(_) => true,
+        Err(_) => false,
+    }
+}
+
+/// Wait for a port to become available
+pub async fn wait_for_port(port: u16) {
+    for _ in 0..50 {
+        if is_port_open(port).await {
+            return;
+        }
+        time::sleep(Duration::from_millis(10)).await;
+    }
+
+    eprintln!("Port {} did not open in time!", port);
+    std::process::exit(2);
+}
+
+mod test {
+    use crate::test::dummy_tcp_sockets::{
+        dummy_tcp_client_read_conn, dummy_tcp_client_square_root_requests,
+        dummy_tcp_client_write_conn, dummy_tcp_client_write_then_read_conn, DummyTCPServer,
+    };
+    use crate::test::{get_port_number, PortsAllocation};
+
+    fn port(index: u16) -> u16 {
+        get_port_number(PortsAllocation::DummyTCPServer, index)
+    }
+
+    #[tokio::test]
+    async fn socket_read_from_server() {
+        const DATA: &[u8] = "Hello world!!!".as_bytes();
+
+        let listener = DummyTCPServer::start(port(0)).await;
+        let handle = tokio::spawn(async move {
+            listener.write_next_connection(DATA).await;
+        });
+        let data = dummy_tcp_client_read_conn(port(0)).await;
+        assert_eq!(data, DATA);
+
+        handle.await.unwrap();
+    }
+
+    #[tokio::test]
+    async fn socket_write_to_server() {
+        const DATA: &[u8] = "Hello world 2".as_bytes();
+
+        let listener = DummyTCPServer::start(port(1)).await;
+        tokio::spawn(async move {
+            dummy_tcp_client_write_conn(port(1), DATA).await;
+        });
+        let data = listener.read_next_connection().await;
+        assert_eq!(data, DATA);
+    }
+
+    #[tokio::test]
+    async fn socket_read_and_write_to_server() {
+        const DATA_1: &[u8] = "Hello world 3a".as_bytes();
+        const DATA_2: &[u8] = "Hello world 3b".as_bytes();
+
+        let listener = DummyTCPServer::start(port(2)).await;
+        let handle = tokio::spawn(async move {
+            println!("client handle");
+            let data = dummy_tcp_client_write_then_read_conn(port(2), DATA_1).await;
+            assert_eq!(data, DATA_2);
+        });
+        let h2 = tokio::spawn(async move {
+            println!("server handle");
+            let data = listener.read_then_write_next_connection(DATA_2).await;
+            assert_eq!(data, DATA_1);
+        });
+
+        handle.await.unwrap();
+        h2.await.unwrap();
+    }
+
+    #[tokio::test]
+    async fn socket_dummy_root_calculator() {
+        let listener = DummyTCPServer::start(port(3)).await;
+        let handle = tokio::spawn(async move {
+            listener.next_conn_square_operations().await;
+        });
+        let data = dummy_tcp_client_write_then_read_conn(port(3), "5".as_bytes()).await;
+        assert_eq!(data, "25".as_bytes());
+
+        handle.await.unwrap();
+    }
+
+    #[tokio::test]
+    async fn socket_dummy_root_calculator_multiple() {
+        let listener = DummyTCPServer::start(port(4)).await;
+        let handle = tokio::spawn(async move {
+            listener.next_conn_square_operations().await;
+        });
+        dummy_tcp_client_square_root_requests(port(4), 10).await;
+
+        handle.await.unwrap();
+    }
+}