Normalize AppCode equality for custom codes

CHANGELOG.md

@@ -3,6 +3,17 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+## [0.24.9] - 2025-10-25
+
+### Fixed
+- Treat compile-time and runtime custom `AppCode` values as equal by comparing
+  their canonical string representation, restoring successful JSON roundtrips
+  for `AppCode::new("…")` literals.
+
+### Changed
+- Equality for `AppCode` is now string-based; prefer `==` checks instead of
+  pattern matching on `AppCode::Variant` constants.
+
 ## [0.24.8] - 2025-10-24
 
 ### Changed

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "masterror"
-version = "0.24.8"
+version = "0.24.9"
 rust-version = "1.90"
 edition = "2024"
 license = "MIT OR Apache-2.0"

src/code/app_code.rs

@@ -1,7 +1,11 @@
-use alloc::{borrow::ToOwned, boxed::Box, string::String};
+use alloc::{
+    borrow::{Cow, ToOwned},
+    string::String
+};
 use core::{
     error::Error as CoreError,
     fmt::{self, Display},
+    hash::{Hash, Hasher},
     str::FromStr
 };
 
@@ -44,15 +48,9 @@ impl CoreError for ParseAppCodeError {}
 /// - Validate custom codes using [`AppCode::try_new`] before exposing them
 ///   publicly.
 #[non_exhaustive]
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone)]
 pub struct AppCode {
-    repr: CodeRepr
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-enum CodeRepr {
-    Static(&'static str),
-    Owned(Box<str>)
+    repr: Cow<'static, str>
 }
 
 #[allow(non_upper_case_globals)]
@@ -108,13 +106,13 @@ impl AppCode {
 
     const fn from_static(code: &'static str) -> Self {
         Self {
-            repr: CodeRepr::Static(code)
+            repr: Cow::Borrowed(code)
         }
     }
 
     fn from_owned(code: String) -> Self {
         Self {
-            repr: CodeRepr::Owned(code.into_boxed_str())
+            repr: Cow::Owned(code)
         }
     }
 
@@ -169,10 +167,21 @@ impl AppCode {
     /// This matches the JSON serialization.
     #[must_use]
     pub fn as_str(&self) -> &str {
-        match &self.repr {
-            CodeRepr::Static(value) => value,
-            CodeRepr::Owned(value) => value
-        }
+        self.repr.as_ref()
+    }
+}
+
+impl PartialEq for AppCode {
+    fn eq(&self, other: &Self) -> bool {
+        self.as_str() == other.as_str()
+    }
+}
+
+impl Eq for AppCode {}
+
+impl Hash for AppCode {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.as_str().hash(state);
     }
 }
 

src/lib.rs

@@ -263,7 +263,7 @@
 //! let app_err = AppError::new(AppErrorKind::NotFound, "user_not_found");
 //! let resp: ErrorResponse = (&app_err).into();
 //! assert_eq!(resp.status, 404);
-//! assert!(matches!(resp.code, AppCode::NotFound));
+//! assert_eq!(resp.code, AppCode::NotFound);
 //! ```
 //!
 //! # Typed control-flow macros
@@ -393,7 +393,7 @@ pub use kind::AppErrorKind;
 ///     name: "other"
 /// }
 /// .into();
-/// assert!(matches!(code, AppCode::BadRequest));
+/// assert_eq!(code, AppCode::BadRequest);
 /// ```
 pub use masterror_derive::{Error, Masterror};
 pub use response::{

src/response/tests.rs

@@ -9,7 +9,7 @@ use crate::{AppCode, AppError, AppErrorKind, ProblemJson};
 fn new_sets_status_code_and_message() {
     let e = ErrorResponse::new(404, AppCode::NotFound, "missing").expect("status");
     assert_eq!(e.status, 404);
-    assert!(matches!(e.code, AppCode::NotFound));
+    assert_eq!(e.code, AppCode::NotFound);
     assert_eq!(e.message, "missing");
     assert!(e.retry.is_none());
     assert!(e.www_authenticate.is_none());
@@ -246,7 +246,7 @@ fn from_app_error_preserves_status_and_sets_code() {
     let app = AppError::new(AppErrorKind::NotFound, "user");
     let e: ErrorResponse = (&app).into();
     assert_eq!(e.status, 404);
-    assert!(matches!(e.code, AppCode::NotFound));
+    assert_eq!(e.code, AppCode::NotFound);
     assert_eq!(e.message, "user");
     assert!(e.retry.is_none());
 }
@@ -256,7 +256,7 @@ fn from_app_error_uses_default_message_when_none() {
     let app = AppError::bare(AppErrorKind::Internal);
     let e: ErrorResponse = (&app).into();
     assert_eq!(e.status, 500);
-    assert!(matches!(e.code, AppCode::Internal));
+    assert_eq!(e.code, AppCode::Internal);
     assert_eq!(e.message, AppErrorKind::Internal.label());
 }
 
@@ -269,7 +269,7 @@ fn from_owned_app_error_moves_message_and_metadata() {
     let resp: ErrorResponse = err.into();
 
     assert_eq!(resp.status, 401);
-    assert!(matches!(resp.code, AppCode::Unauthorized));
+    assert_eq!(resp.code, AppCode::Unauthorized);
     assert_eq!(resp.message, "owned message");
     assert_eq!(resp.retry.unwrap().after_seconds, 5);
     assert_eq!(resp.www_authenticate.as_deref(), Some("Bearer"));
@@ -280,7 +280,7 @@ fn from_owned_app_error_defaults_message_when_absent() {
     let resp: ErrorResponse = AppError::bare(AppErrorKind::Internal).into();
 
     assert_eq!(resp.status, 500);
-    assert!(matches!(resp.code, AppCode::Internal));
+    assert_eq!(resp.code, AppCode::Internal);
     assert_eq!(resp.message, AppErrorKind::Internal.label());
 }
 
@@ -290,7 +290,7 @@ fn from_app_error_bare_uses_kind_display_as_message() {
     let resp: ErrorResponse = app.into();
 
     assert_eq!(resp.status, 504);
-    assert!(matches!(resp.code, AppCode::Timeout));
+    assert_eq!(resp.code, AppCode::Timeout);
     assert_eq!(resp.message, AppErrorKind::Timeout.label());
 }
 
@@ -367,7 +367,7 @@ fn display_is_concise_and_does_not_leak_details() {
 fn new_legacy_defaults_to_internal_code() {
     let e = ErrorResponse::new_legacy(404, "boom");
     assert_eq!(e.status, 404);
-    assert!(matches!(e.code, AppCode::Internal));
+    assert_eq!(e.code, AppCode::Internal);
     assert_eq!(e.message, "boom");
 }
 
@@ -376,7 +376,7 @@ fn new_legacy_defaults_to_internal_code() {
 fn new_legacy_invalid_status_falls_back_to_internal_error() {
     let e = ErrorResponse::new_legacy(0, "boom");
     assert_eq!(e.status, 500);
-    assert!(matches!(e.code, AppCode::Internal));
+    assert_eq!(e.code, AppCode::Internal);
     assert_eq!(e.message, "boom");
 }
 

tests/ui/app_error/pass/enum.rs

@@ -26,5 +26,5 @@ fn main() {
     assert!(app_backend.message.is_none());
 
     let code: AppCode = ApiError::Backend.into();
-    assert!(matches!(code, AppCode::Service));
+    assert_eq!(code, AppCode::Service);
 }

tests/ui/app_error/pass/struct.rs

@@ -14,5 +14,5 @@ fn main() {
     assert_eq!(app.message.as_deref(), Some("missing flag: feature"));
 
     let code: AppCode = MissingFlag { name: "other" }.into();
-    assert!(matches!(code, AppCode::BadRequest));
+    assert_eq!(code, AppCode::BadRequest);
 }