test: refactor tests

tests/health_check.rs

@@ -1,25 +1,25 @@
-use std::net::SocketAddr;
-
 use tokio::net::TcpListener;
-use zero2prod::app;
 
 #[tokio::test]
 async fn health_check() {
-    spawn_app();
+    let address = spawn_app().await;
+    let url = format!("{}/health_check", &address);
     let client = reqwest::Client::new();
     let response = client
-        .get("http://localhost:8000/health_check")
+        .get(&url)
         .send()
         .await
-        .expect("Failed to execute request.");
+        .expect("Failed to execute request");
+
     assert!(response.status().is_success());
     assert_eq!(Some(0), response.content_length());
 }
 
-fn spawn_app() {
-    let addr = SocketAddr::from(([127, 0, 0, 1], 8000));
-    let _ = tokio::spawn(async move {
-        let listener = TcpListener::bind(addr).await.unwrap();
-        axum::serve(listener, app()).await.unwrap();
-    });
+async fn spawn_app() -> String {
+    let listener = TcpListener::bind("127.0.0.1:0")
+        .await
+        .expect("Failed to bind random port");
+    let port = listener.local_addr().unwrap().port();
+    let _ = tokio::spawn(async move { axum::serve(listener, zero2prod::app()).await.unwrap() });
+    format!("http://127.0.0.1:{}", port)
 }