/health_check with integration test implemented

tests/health_check.rs

@@ -0,0 +1,23 @@
+use std::net::TcpListener;
+
+#[tokio::test]
+async fn health_check_works() {
+	let address = spawn_app();
+	let health_check_endpoint = format!("{}/health_check", address);
+	let client = reqwest::Client::new();
+	let response = client.get(health_check_endpoint)
+		.send().await.expect("Failed to execute request.");
+
+	assert!(response.status().is_success());
+	assert_eq!(Some(0), response.content_length());
+}
+
+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("Failed to bind address");
+	tokio::spawn(server);
+
+	format!("http://127.0.0.1:{}", port)
+}