refactor: better indication of data conversion

src/routes/subscriptions.rs

@@ -19,6 +19,16 @@ struct FormData {
     name: String,
 }
 
+impl TryFrom<FormData> for NewSubscriber {
+    type Error = String;
+
+    fn try_from(value: FormData) -> Result<Self, Self::Error> {
+        let name = SubscriberName::parse(value.name)?;
+        let email = SubscriberEmail::parse(value.email)?;
+        Ok(Self { email, name })
+    }
+}
+
 #[tracing::instrument(
     name = "Adding a new subscriber",
     skip(form, pool),
@@ -29,25 +39,18 @@ struct FormData {
     )
 )]
 pub async fn subscribe(State(pool): State<PgPool>, Form(form): Form<FormData>) -> Response {
-    let name = match SubscriberName::parse(form.name) {
-        Ok(name) => name,
+    let new_subscriber = match form.try_into() {
+        Ok(form) => form,
         Err(_) => {
-            return (StatusCode::BAD_REQUEST, "Invalid name").into_response();
+            return (StatusCode::BAD_REQUEST, "Invalid subscription.").into_response();
         }
     };
-    let email = match SubscriberEmail::parse(form.email) {
-        Ok(email) => email,
-        Err(_) => {
-            return (StatusCode::BAD_REQUEST, "Invalid email address").into_response();
-        }
-    };
-    let new_subscriber = NewSubscriber { email, name };
     match insert_subscriber(&pool, &new_subscriber).await {
         Ok(_) => {
             return (StatusCode::OK,).into_response();
         }
         Err(_) => {
-            return (StatusCode::INTERNAL_SERVER_ERROR, "Something went wrong").into_response();
+            return (StatusCode::INTERNAL_SERVER_ERROR, "Something went wrong.").into_response();
         }
     }
 }