fix: return 400 instead of 404 for missing client IP header

src/error.rs

@@ -4,6 +4,7 @@ use axum::response::{IntoResponse, Response};
 pub enum AppError {
     IpNotFound,
     InvalidIp,
+    MissingClientIp,
     DbLookupFailed,
 }
 
@@ -12,6 +13,7 @@ impl IntoResponse for AppError {
         let (status, message) = match self {
             Self::IpNotFound => (StatusCode::NOT_FOUND, "IP not found in database"),
             Self::InvalidIp => (StatusCode::BAD_REQUEST, "Invalid IP address"),
+            Self::MissingClientIp => (StatusCode::BAD_REQUEST, "Missing client IP address"),
             Self::DbLookupFailed => (StatusCode::INTERNAL_SERVER_ERROR, "Database lookup failed"),
         };
         (status, message).into_response()

src/handlers.rs

@@ -52,7 +52,7 @@ fn extract_client_ip(headers: &HeaderMap) -> Result<IpAddr, AppError> {
         .get("CF-Connecting-IP")
         .and_then(|v| v.to_str().ok())
         .and_then(|s| s.trim().parse().ok())
-        .ok_or(AppError::IpNotFound)
+        .ok_or(AppError::MissingClientIp)
 }
 
 fn lookup_ip(db: &SharedDb, ip: IpAddr) -> Result<IpInfo, AppError> {

tests/integration.rs

@@ -231,7 +231,7 @@ async fn root_without_cf_header_returns_error() {
         )],
     )
     .await;
-    assert_eq!(status, StatusCode::NOT_FOUND);
+    assert_eq!(status, StatusCode::BAD_REQUEST);
 }
 
 #[tokio::test]