fix: address review findings

src/error.rs

@@ -3,6 +3,8 @@ use serde::Serialize;
 
 #[derive(Debug, thiserror::Error)]
 pub enum AppError {
+    #[error("bad request: {0}")]
+    BadRequest(String),
     #[error("pokemon not found")]
     NotFound,
     #[error("upstream service returned invalid data: {0}")]
@@ -19,6 +21,7 @@ impl AppError {
     #[must_use]
     pub const fn status_code(&self) -> StatusCode {
         match self {
+            Self::BadRequest(_) => StatusCode::BAD_REQUEST,
             Self::NotFound => StatusCode::NOT_FOUND,
             Self::InvalidUpstreamData(_) | Self::Upstream(_) | Self::Timeout => {
                 StatusCode::BAD_GATEWAY
@@ -32,12 +35,24 @@ impl IntoResponse for AppError {
     fn into_response(self) -> axum::response::Response {
         let status = self.status_code();
         let body = ErrorBody {
-            error: self.to_string(),
+            error: self.public_message(),
         };
         (status, Json(body)).into_response()
     }
 }
 
+impl AppError {
+    fn public_message(&self) -> String {
+        match self {
+            Self::BadRequest(message) => message.clone(),
+            Self::NotFound => "pokemon not found".to_owned(),
+            Self::InvalidUpstreamData(_) => "upstream service returned invalid data".to_owned(),
+            Self::Upstream(_) | Self::Timeout => "upstream service failed".to_owned(),
+            Self::Internal => "internal server error".to_owned(),
+        }
+    }
+}
+
 #[derive(Serialize)]
 struct ErrorBody {
     error: String,