Bind the server to a random port in tests

src/lib.rs

@@ -1,12 +1,14 @@
+use std::net::TcpListener;
+
 use actix_web::{dev::Server, web, App, HttpResponse, HttpServer, Responder};
 
 async fn health_check() -> impl Responder {
     HttpResponse::Ok()
 }
 
-pub fn run() -> Result<Server, std::io::Error> {
+pub fn run(listener: TcpListener) -> Result<Server, std::io::Error> {
     let server = HttpServer::new(|| App::new().route("/health_check", web::get().to(health_check)))
-        .bind("127.0.0.1:8000")?
+        .listen(listener)?
         .run();
     Ok(server)
 }

src/main.rs

@@ -1,6 +1,9 @@
+use std::net::TcpListener;
+
 use zero2prod::run;
 
 #[tokio::main]
 async fn main() -> Result<(), std::io::Error> {
-    run()?.await
+    let listener = TcpListener::bind("127.0.0.1:8000").expect("Failed to bind address");
+    run(listener)?.await
 }

tests/health_check.rs

@@ -1,13 +1,14 @@
+use std::net::TcpListener;
+
 #[tokio::test]
 async fn health_check_works() {
     // Arrange
-    spawn_app();
-
+    let address = spawn_app();
     let client = reqwest::Client::new();
 
     // Act
     let response = client
-        .get("http://127.0.0.1:8000/health_check")
+        .get(&format!("{}/health_check", &address))
         .send()
         .await
         .expect("Faied to execute request.");
@@ -17,7 +18,10 @@ async fn health_check_works() {
     assert_eq!(Some(0), response.content_length());
 }
 
-fn spawn_app() {
-    let server = zero2prod::run().expect("Failder to bind address");
+fn spawn_app() -> String {
+    let listener = TcpListener::bind("127.0.0.1:0").expect("Failed to bind random port");
+    let port = listener.local_addr().unwrap().port();
+    let server = zero2prod::run(listener).expect("Failder to bind address");
     let _ = tokio::spawn(server);
+    format!("http://127.0.0.1:{}", port)
 }