feat: add route and tests

tests/health_check.rs

@@ -6,29 +6,77 @@ struct TestApp {
 
 #[tokio::test]
 async fn health_check_works() {
+    // Arrange
     let TestApp { addr, .. } = spawn_app().await;
 
+    // Act
     let client = reqwest::Client::new();
     let response = client
         .get(format!("http://{addr}/health_check"))
         .send()
         .await
         .expect("Failed to execute request.");
+
+    // Assert
     assert!(response.status().is_success());
     assert_eq!(Some(0), response.content_length());
 }
 
-// fn spawn_app() {
-//     let server = learn_axum::run().expect("Failed to bind address.");
-//     tokio::spawn(server);
-// }
+#[tokio::test]
+async fn subscribe_returns_a_200_for_valid_form_data() {
+    // Arrange
+    let TestApp { addr, .. } = spawn_app().await;
+    let client = reqwest::Client::new();
+
+    // Act
+    let body = "name=le%20guin&email=ursula_le_guin%40gmail.com";
+    let response = client
+        .post(&format!("http://{addr}/subscriptions"))
+        .header("Content-Type", "application/x-www-form-urlencoded")
+        .body(body)
+        .send()
+        .await
+        .expect("Failed to execute request.");
+
+    // Assert
+    assert_eq!(200, response.status().as_u16());
+}
+
+#[tokio::test]
+async fn subscribe_returns_a_400_when_data_is_missing() {
+    // Arrange
+    let TestApp { addr, .. } = spawn_app().await;
+    let client = reqwest::Client::new();
+    let test_cases = vec![
+        ("name=le%20guin", "missing the email"),
+        ("email=ursula_le_guin%40gmail.com", "missing the name"),
+        ("", "missing both name and email"),
+    ];
+
+    for (invalid_body, error_message) in test_cases {
+        // Act
+        let response = client
+            .post(&format!("http://{addr}/subscriptions"))
+            .header("Content-Type", "application/x-www-form-urlencoded")
+            .body(invalid_body)
+            .send()
+            .await
+            .expect("Failed to execute request.");
+
+        // Assert
+        assert_eq!(
+            400,
+            response.status().as_u16(),
+            "The API did not fail with 400 Bad Request when the payload was {}.",
+            error_message
+        );
+    }
+}
+
 async fn spawn_app() -> TestApp {
     let listener = TcpListener::bind("127.0.0.1:0").expect("Failed to bind to random port");
     let addr = listener.local_addr().unwrap();
-
     let server = learn_axum::run(listener).expect("Failed to bind to address");
-
     tokio::spawn(server);
-
     TestApp { addr }
 }