api: unify error responses

1 files changed, 35 insertions, 6 deletions

diff --git a/src/api/mod.rs b/src/api/mod.rs
index 093ca6a..021bc52 100644
--- a/src/api/mod.rs
+++ b/src/api/mod.rs
@@ -169,14 +169,43 @@ async fn openapi_spec() -> impl IntoResponse {
 
 // --- shared helpers ----------------------------------------------------------
 
-pub(crate) fn store_status(error: StoreError, context: &str) -> StatusCode {
-    match error {
-        StoreError::Conflict => StatusCode::CONFLICT,
+/// An error answer: its status, and why where it is known (`error_response`); a bare
+/// status otherwise (`json_errors` gives it the body).
+pub(crate) struct ApiError(StatusCode, Option<String>);
+
+impl ApiError {
+    pub(crate) fn status(&self) -> StatusCode {
+        self.0
+    }
+}
+
+impl From<StatusCode> for ApiError {
+    fn from(status: StatusCode) -> Self {
+        Self(status, None)
+    }
+}
+
+impl IntoResponse for ApiError {
+    fn into_response(self) -> Response {
+        match self.1 {
+            Some(message) => error_response(self.0, message, None),
+            None => self.0.into_response(),
+        }
+    }
+}
+
+/// A store error as an answer, saying why (`StoreError`'s text) where it is the
+/// client's; others are logged with `context`, and are a bare `500`.
+pub(crate) fn store_status(error: StoreError, context: &str) -> ApiError {
+    let status = match error {
+        StoreError::Conflict | StoreError::NotAList | StoreError::PastTheEnd { .. } => {
+            StatusCode::CONFLICT
+        }
         StoreError::NotFound => StatusCode::NOT_FOUND,
-        StoreError::NotAList | StoreError::PastTheEnd { .. } => StatusCode::CONFLICT,
         other => {
             error!(error = %format!("{other:#}"), "{context}");
-            StatusCode::INTERNAL_SERVER_ERROR
+            return StatusCode::INTERNAL_SERVER_ERROR.into();
         }
-    }
+    };
+    ApiError(status, Some(error.to_string()))
 }