test: dynamically find open port for test relay

Cargo.lock

@@ -976,6 +976,7 @@ checksum = "38bf9645c8b145698bb0b18a4637dcacbc421ea49bef2317e4fd8065a387cf21"
 name = "nostr-rs-relay"
 version = "0.6.2"
 dependencies = [
+ "anyhow",
  "bitcoin_hashes",
  "config",
  "console-subscriber",

Cargo.toml

@@ -31,3 +31,6 @@ hyper-tls = "0.5"
 http = { version = "0.2" }
 parse_duration = "2"
 rand = "0.8"
+
+[dev-dependencies]
+anyhow = "1"

tests/common/mod.rs

@@ -1,29 +1,52 @@
+use anyhow::Result;
 use log::*;
 use nostr_rs_relay::config;
 use nostr_rs_relay::server::start_server;
+use std::net::TcpListener;
 use std::sync::mpsc as syncmpsc;
 use std::sync::mpsc::{Receiver as MpscReceiver, Sender as MpscSender};
 use std::thread;
 use std::thread::JoinHandle;
 
 pub struct Relay {
+    pub port: u16,
     pub handle: JoinHandle<()>,
     pub shutdown_tx: MpscSender<()>,
 }
 
-pub fn start_relay(port: u16) -> Relay {
+pub fn start_relay() -> Result<Relay> {
     let _ = env_logger::try_init();
     info!("Starting up from main");
     // replace default settings
     let mut settings = config::Settings::default();
-    settings.database.in_memory = true;
+    // identify open port
+    let port = get_available_port().unwrap();
+    info!("Starting relay on port {}", port);
+    // bind to local interface only
+    settings.network.address = "127.0.0.1".to_owned();
     settings.network.port = port;
+    // create an in-memory DB with multiple readers
+    settings.database.in_memory = true;
+    settings.database.min_conn = 4;
+    settings.database.max_conn = 8;
     let (shutdown_tx, shutdown_rx): (MpscSender<()>, MpscReceiver<()>) = syncmpsc::channel();
     let handle = thread::spawn(|| {
         let _ = start_server(settings, shutdown_rx);
     });
-    return Relay {
+    return Ok(Relay {
+        port,
         handle,
         shutdown_tx,
-    };
+    });
+}
+
+// from https://elliotekj.com/posts/2017/07/25/find-available-tcp-port-rust/
+fn get_available_port() -> Option<u16> {
+    (4000..20000).find(|port| port_is_available(*port))
+}
+fn port_is_available(port: u16) -> bool {
+    match TcpListener::bind(("127.0.0.1", port)) {
+        Ok(_) => true,
+        Err(_) => false,
+    }
 }

tests/integration_test.rs

@@ -1,11 +1,12 @@
+use anyhow::Result;
 use std::thread;
 use std::time::Duration;
 
 mod common;
 
 #[test]
-fn startup() {
+fn startup() -> Result<()> {
-    let relay = common::start_relay(8080);
+    let relay = common::start_relay()?;
     // just make sure we can startup and shut down.
     // if we send a shutdown message before the server is listening,
     // we will get a SendError.  Keep sending until someone is
@@ -24,4 +25,5 @@ fn startup() {
     // wait for relay to shutdown
     let thread_join = relay.handle.join();
     assert!(thread_join.is_ok());
+    Ok(())
 }