refactor: single refusal shape with openapi contract test

crates/adapters/http-axum/src/errors.rs

@@ -1,9 +1,30 @@
+use api_types::ErrorResponse;
 use axum::{
     http::StatusCode,
     response::{IntoResponse, Response},
 };
 use domain::errors::DomainError;
 
+pub const NOT_FOUND: &str = "NOT_FOUND";
+pub const INVALID_INPUT: &str = "INVALID_INPUT";
+pub const CONFLICT: &str = "CONFLICT";
+pub const UNAUTHORIZED: &str = "UNAUTHORIZED";
+pub const FORBIDDEN: &str = "FORBIDDEN";
+pub const RATE_LIMITED: &str = "RATE_LIMITED";
+pub const INTERNAL: &str = "INTERNAL";
+
+/// The only constructor of JSON error bodies in this crate.
+pub fn refuse(status: StatusCode, code: &'static str, message: impl Into<String>) -> Response {
+    (
+        status,
+        axum::Json(ErrorResponse {
+            error: message.into(),
+            code: code.to_string(),
+        }),
+    )
+        .into_response()
+}
+
 pub fn domain_error_status(e: &DomainError) -> StatusCode {
     match e {
         DomainError::InvalidRating { .. } | DomainError::ValidationError(_) => {
@@ -38,19 +59,16 @@ impl IntoResponse for ApiError {
     fn into_response(self) -> Response {
         let status = domain_error_status(&self.0);
         match &self.0 {
+            DomainError::InvalidRating { .. } | DomainError::ValidationError(_) => {
+                refuse(status, INVALID_INPUT, self.0.to_string())
+            }
+            DomainError::NotFound(_) => refuse(status, NOT_FOUND, self.0.to_string()),
+            DomainError::Unauthorized(_) => refuse(status, UNAUTHORIZED, self.0.to_string()),
+            DomainError::Forbidden(_) => refuse(status, FORBIDDEN, self.0.to_string()),
             DomainError::InfrastructureError(_) => {
                 tracing::error!("Internal error: {:?}", self.0);
-                (
-                    status,
-                    axum::Json(serde_json::json!({"error": "internal server error"})),
-                )
-                    .into_response()
+                refuse(status, INTERNAL, "internal server error")
             }
-            _ => (
-                status,
-                axum::Json(serde_json::json!({"error": self.0.to_string()})),
-            )
-                .into_response(),
         }
     }
 }