Move AppCode out of context when promoting errors

CHANGELOG.md

@@ -3,6 +3,14 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+## [0.24.1] - 2025-10-17
+
+### Fixed
+- Updated `Context::into_error` to move dynamic `AppCode` values into the
+  resulting `AppError`, reworking field redaction plumbing to avoid clones and
+  preserve custom code ownership. Added a regression test covering pointer
+  identity for context-promoted errors.
+
 ## [0.24.0] - 2025-10-16
 
 ### Added

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "masterror"
-version = "0.24.0"
+version = "0.24.1"
 rust-version = "1.90"
 edition = "2024"
 license = "MIT OR Apache-2.0"

README.md

@@ -74,9 +74,9 @@ The build script keeps the full feature snippet below in sync with
 
 ~~~toml
 [dependencies]
-masterror = { version = "0.24.0", default-features = false }
+masterror = { version = "0.24.1", default-features = false }
 # or with features:
-# masterror = { version = "0.24.0", features = [
+# masterror = { version = "0.24.1", features = [
 #   "std", "axum", "actix", "openapi",
 #   "serde_json", "tracing", "metrics", "backtrace",
 #   "sqlx", "sqlx-migrate", "reqwest", "redis",

src/app_error/context.rs

@@ -91,7 +91,7 @@ impl Context {
     #[must_use]
     pub fn with(mut self, field: Field) -> Self {
         self.fields.push(field);
-        self.apply_field_redactions();
+        Self::apply_field_redactions(&mut self.fields, &self.field_policies);
         self
     }
 
@@ -132,35 +132,45 @@ impl Context {
         self
     }
 
-    pub(crate) fn into_error<E>(mut self, source: E) -> Error
+    pub(crate) fn into_error<E>(self, source: E) -> Error
     where
         E: CoreError + Send + Sync + 'static
     {
-        if let Some(location) = self.caller_location {
-            self.fields.push(Field::new(
+        let Context {
+            mut fields,
+            field_policies,
+            edit_policy,
+            caller_location,
+            code,
+            category,
+            ..
+        } = self;
+
+        if let Some(location) = caller_location {
+            fields.push(Field::new(
                 "caller.file",
                 FieldValue::Str(location.file().into())
             ));
-            self.fields.push(Field::new(
+            fields.push(Field::new(
                 "caller.line",
                 FieldValue::U64(u64::from(location.line()))
             ));
-            self.fields.push(Field::new(
+            fields.push(Field::new(
                 "caller.column",
                 FieldValue::U64(u64::from(location.column()))
             ));
         }
 
-        let mut error = AppError::new_raw(self.category, None);
-        error.code = self.code.clone();
-        if !self.fields.is_empty() {
-            self.apply_field_redactions();
-            error.metadata.extend(self.fields);
+        let mut error = AppError::new_raw(category, None);
+        error.code = code;
+        if !fields.is_empty() {
+            Self::apply_field_redactions(&mut fields, &field_policies);
+            error.metadata.extend(fields);
         }
-        for &(name, redaction) in &self.field_policies {
+        for &(name, redaction) in &field_policies {
             error = error.redact_field(name, redaction);
         }
-        if matches!(self.edit_policy, MessageEditPolicy::Redact) {
+        if matches!(edit_policy, MessageEditPolicy::Redact) {
             error.edit_policy = MessageEditPolicy::Redact;
         }
         let error = error.with_context(source);
@@ -170,13 +180,15 @@ impl Context {
 }
 
 impl Context {
-    fn apply_field_redactions(&mut self) {
-        if self.field_policies.is_empty() {
+    fn apply_field_redactions(
+        fields: &mut Vec<Field>,
+        policies: &[(&'static str, FieldRedaction)]
+    ) {
+        if policies.is_empty() {
             return;
         }
-        for field in &mut self.fields {
-            if let Some((_, policy)) = self
-                .field_policies
+        for field in fields {
+            if let Some((_, policy)) = policies
                 .iter()
                 .rev()
                 .find(|(name, _)| *name == field.name())

src/app_error/tests.rs

@@ -39,7 +39,7 @@ static BACKTRACE_ENV_GUARD: Mutex<()> = Mutex::new(());
 static TELEMETRY_GUARD: Mutex<()> = Mutex::new(());
 
 use super::{AppError, FieldRedaction, FieldValue, MessageEditPolicy, field};
-use crate::{AppCode, AppErrorKind, ErrorResponse};
+use crate::{AppCode, AppErrorKind, Context, ErrorResponse, ResultExt};
 
 // --- Helpers -------------------------------------------------------------
 
@@ -198,6 +198,19 @@ fn retry_and_www_authenticate_are_attached() {
     assert_eq!(err.www_authenticate.as_deref(), Some("Bearer"));
 }
 
+#[test]
+fn context_moves_dynamic_code_without_cloning() {
+    let dynamic_code =
+        AppCode::try_new(String::from("THIRD_PARTY_FAILURE")).expect("valid dynamic code");
+    let expected_ptr = dynamic_code.as_str().as_ptr();
+
+    let err = Result::<(), IoError>::Err(IoError::from(IoErrorKind::Other))
+        .ctx(|| Context::new(AppErrorKind::Service).code(dynamic_code))
+        .unwrap_err();
+
+    assert_eq!(err.code.as_str().as_ptr(), expected_ptr);
+}
+
 #[test]
 fn render_message_does_not_allocate_for_borrowed_str() {
     let err = AppError::new(AppErrorKind::BadRequest, "borrowed");

tests/ui/app_error/fail/enum_missing_variant.stderr

@@ -1,14 +1,13 @@
 error: all variants must use #[app_error(...)] to derive AppError conversion
  --> tests/ui/app_error/fail/enum_missing_variant.rs:8:5
   |
-8 | /     #[error("without")]
-9 | |     Without,
-  | |___________^
+8 |     #[error("without")]
+  |     ^
 
 warning: unused import: `AppErrorKind`
  --> tests/ui/app_error/fail/enum_missing_variant.rs:1:17
   |
 1 | use masterror::{AppErrorKind, Error};
   |                 ^^^^^^^^^^^^
   |
-  = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
+  = note: `#[warn(unused_imports)]` on by default

tests/ui/app_error/fail/missing_code.stderr

@@ -2,12 +2,12 @@ error: AppCode conversion requires `code = ...` in #[app_error(...)]
  --> tests/ui/app_error/fail/missing_code.rs:9:5
   |
 9 |     #[app_error(kind = AppErrorKind::Service)]
-  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  |     ^
 
 warning: unused imports: `AppCode` and `AppErrorKind`
  --> tests/ui/app_error/fail/missing_code.rs:1:17
   |
 1 | use masterror::{AppCode, AppErrorKind, Error};
   |                 ^^^^^^^  ^^^^^^^^^^^^
   |
-  = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
+  = note: `#[warn(unused_imports)]` on by default

tests/ui/app_error/fail/missing_kind.stderr

@@ -2,4 +2,4 @@ error: missing `kind = ...` in #[app_error(...)]
  --> tests/ui/app_error/fail/missing_kind.rs:5:1
   |
 5 | #[app_error(message)]
-  | ^^^^^^^^^^^^^^^^^^^^^
+  | ^

tests/ui/formatter/fail/duplicate_fmt.stderr

@@ -2,4 +2,4 @@ error: duplicate `fmt` handler specified
  --> tests/ui/formatter/fail/duplicate_fmt.rs:4:36
   |
 4 | #[error(fmt = crate::format_error, fmt = crate::format_error)]
-  |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^
+  |                                    ^^^

tests/ui/formatter/fail/implicit_after_named.stderr

@@ -8,5 +8,4 @@ error: multiple unused formatting arguments
   |                 argument never used
   |                 argument never used
   |
-  = note: consider adding 2 format specifiers
   = note: this error originates in the derive macro `Error` (in Nightly builds, run with -Z macro-backtrace for more info)

tests/ui/formatter/fail/unsupported_flag.stderr

@@ -1,5 +1,5 @@
 error: placeholder spanning bytes 0..11 uses an unsupported formatter
- --> tests/ui/formatter/fail/unsupported_flag.rs:4:10
+ --> tests/ui/formatter/fail/unsupported_flag.rs:4:9
   |
 4 | #[error("{value:##x}")]
-  |          ^^^^^^^^^^^
+  |         ^^^^^^^^^^^^^

tests/ui/formatter/fail/unsupported_formatter.stderr

@@ -1,5 +1,5 @@
 error: placeholder spanning bytes 0..9 uses an unsupported formatter
- --> tests/ui/formatter/fail/unsupported_formatter.rs:4:10
+ --> tests/ui/formatter/fail/unsupported_formatter.rs:4:9
   |
 4 | #[error("{value:y}")]
-  |          ^^^^^^^^^
+  |         ^^^^^^^^^^^

tests/ui/formatter/fail/uppercase_binary.stderr

@@ -1,5 +1,5 @@
 error: placeholder spanning bytes 0..9 uses an unsupported formatter
- --> tests/ui/formatter/fail/uppercase_binary.rs:4:10
+ --> tests/ui/formatter/fail/uppercase_binary.rs:4:9
   |
 4 | #[error("{value:B}")]
-  |          ^^^^^^^^^
+  |         ^^^^^^^^^^^

tests/ui/formatter/fail/uppercase_pointer.stderr

@@ -1,5 +1,5 @@
 error: placeholder spanning bytes 0..9 uses an unsupported formatter
- --> tests/ui/formatter/fail/uppercase_pointer.rs:4:10
+ --> tests/ui/formatter/fail/uppercase_pointer.rs:4:9
   |
 4 | #[error("{value:P}")]
-  |          ^^^^^^^^^
+  |         ^^^^^^^^^^^

tests/ui/masterror/fail/duplicate_attr.stderr

@@ -10,4 +10,4 @@ warning: unused imports: `AppCode` and `AppErrorKind`
 1 | use masterror::{AppCode, AppErrorKind, Masterror};
   |                 ^^^^^^^  ^^^^^^^^^^^^
   |
-  = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
+  = note: `#[warn(unused_imports)]` on by default

tests/ui/masterror/fail/duplicate_telemetry.stderr

@@ -10,4 +10,4 @@ warning: unused imports: `AppCode` and `AppErrorKind`
 1 | use masterror::{AppCode, AppErrorKind, Masterror};
   |                 ^^^^^^^  ^^^^^^^^^^^^
   |
-  = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
+  = note: `#[warn(unused_imports)]` on by default

tests/ui/masterror/fail/empty_redact.stderr

@@ -10,4 +10,4 @@ warning: unused imports: `AppCode` and `AppErrorKind`
 1 | use masterror::{AppCode, AppErrorKind, Masterror};
   |                 ^^^^^^^  ^^^^^^^^^^^^
   |
-  = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
+  = note: `#[warn(unused_imports)]` on by default

tests/ui/masterror/fail/enum_missing_variant.stderr

@@ -1,14 +1,13 @@
 error: all variants must use #[masterror(...)] to derive masterror::Error conversion
  --> tests/ui/masterror/fail/enum_missing_variant.rs:8:5
   |
-8 | /     #[error("missing")]
-9 | |     Missing
-  | |___________^
+8 |     #[error("missing")]
+  |     ^
 
 warning: unused imports: `AppCode` and `AppErrorKind`
  --> tests/ui/masterror/fail/enum_missing_variant.rs:1:17
   |
 1 | use masterror::{AppCode, AppErrorKind, Masterror};
   |                 ^^^^^^^  ^^^^^^^^^^^^
   |
-  = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
+  = note: `#[warn(unused_imports)]` on by default

tests/ui/masterror/fail/missing_category.stderr

@@ -2,12 +2,12 @@ error: missing `category = ...` in #[masterror(...)]
  --> tests/ui/masterror/fail/missing_category.rs:5:1
   |
 5 | #[masterror(code = AppCode::Internal)]
-  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  | ^
 
 warning: unused import: `AppCode`
  --> tests/ui/masterror/fail/missing_category.rs:1:17
   |
 1 | use masterror::{AppCode, Masterror};
   |                 ^^^^^^^
   |
-  = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
+  = note: `#[warn(unused_imports)]` on by default

tests/ui/masterror/fail/missing_code.stderr

@@ -2,12 +2,12 @@ error: missing `code = ...` in #[masterror(...)]
  --> tests/ui/masterror/fail/missing_code.rs:5:1
   |
 5 | #[masterror(category = AppErrorKind::Internal)]
-  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  | ^
 
 warning: unused import: `AppErrorKind`
  --> tests/ui/masterror/fail/missing_code.rs:1:17
   |
 1 | use masterror::{AppErrorKind, Masterror};
   |                 ^^^^^^^^^^^^
   |
-  = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
+  = note: `#[warn(unused_imports)]` on by default

tests/ui/masterror/fail/unknown_option.stderr

@@ -10,4 +10,4 @@ warning: unused imports: `AppCode` and `AppErrorKind`
 1 | use masterror::{AppCode, AppErrorKind, Masterror};
   |                 ^^^^^^^  ^^^^^^^^^^^^
   |
-  = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
+  = note: `#[warn(unused_imports)]` on by default