Refactor database constructor ergonomics

CHANGELOG.md

@@ -3,6 +3,21 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+## [0.11.0] - 2025-10-26
+
+### Changed
+- Updated `AppError::database` to accept `Option<Cow<'static, str>>`, allowing
+  bare `None` calls without type annotations, and added the helper
+  `AppError::database_with_message` for the common message-bearing path.
+
+### Documentation
+- Refreshed the `AppError::database` docs to illustrate the new constructor
+  behavior and helper usage.
+
+### Tests
+- Expanded database constructor tests to cover both the helper and bare `None`
+  scenario.
+
 ## [0.10.9] - 2025-10-26
 
 ### Fixed

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "masterror"
-version = "0.10.9"
+version = "0.11.0"
 rust-version = "1.90"
 edition = "2024"
 license = "MIT OR Apache-2.0"

README.md

@@ -29,9 +29,9 @@ Stable categories, conservative HTTP mapping, no `unsafe`.
 
 ~~~toml
 [dependencies]
-masterror = { version = "0.10.9", default-features = false }
+masterror = { version = "0.11.0", default-features = false }
 # or with features:
-# masterror = { version = "0.10.9", features = [
+# masterror = { version = "0.11.0", features = [
 #   "axum", "actix", "openapi", "serde_json",
 #   "sqlx", "sqlx-migrate", "reqwest", "redis",
 #   "validator", "config", "tokio", "multipart",
@@ -66,10 +66,11 @@ masterror = { version = "0.10.9", default-features = false }
 ~~~toml
 [dependencies]
 # lean core
-masterror = { version = "0.10.9", default-features = false }
+masterror = { version = "0.11.0", default-features = false }
 
 # with Axum/Actix + JSON + integrations
-# masterror = { version = "0.10.9", features = [
+# masterror = { version = "0.11.0", features = [
+
 #   "axum", "actix", "openapi", "serde_json",
 #   "sqlx", "sqlx-migrate", "reqwest", "redis",
 #   "validator", "config", "tokio", "multipart",
@@ -623,13 +624,13 @@ assert_eq!(resp.status, 401);
 Minimal core:
 
 ~~~toml
-masterror = { version = "0.10.9", default-features = false }
+masterror = { version = "0.11.0", default-features = false }
 ~~~
 
 API (Axum + JSON + deps):
 
 ~~~toml
-masterror = { version = "0.10.9", features = [
+masterror = { version = "0.11.0", features = [
   "axum", "serde_json", "openapi",
   "sqlx", "reqwest", "redis", "validator", "config", "tokio"
 ] }
@@ -638,7 +639,7 @@ masterror = { version = "0.10.9", features = [
 API (Actix + JSON + deps):
 
 ~~~toml
-masterror = { version = "0.10.9", features = [
+masterror = { version = "0.11.0", features = [
   "actix", "serde_json", "openapi",
   "sqlx", "reqwest", "redis", "validator", "config", "tokio"
 ] }

src/app_error/constructors.rs

@@ -51,16 +51,39 @@ impl AppError {
     }
     /// Build a `Database` error with an optional message.
     ///
-    /// Accepts `Option` to avoid gratuitous `.map(|...| ...)` at call sites
-    /// when you may or may not have a safe-to-print string at hand.
-    pub fn database(msg: Option<impl Into<Cow<'static, str>>>) -> Self {
+    /// This constructor accepts a pre-built [`Cow`] so callers that already
+    /// manage ownership can pass either borrowed or owned strings. When you
+    /// have plain string data, prefer [`AppError::database_with_message`].
+    ///
+    /// ```rust
+    /// use masterror::AppError;
+    ///
+    /// let err = AppError::database(None);
+    /// assert!(err.message.is_none());
+    /// ```
+    pub fn database(msg: Option<Cow<'static, str>>) -> Self {
         Self {
             kind:             AppErrorKind::Database,
-            message:          msg.map(Into::into),
+            message:          msg,
             retry:            None,
             www_authenticate: None
         }
     }
+
+    /// Build a `Database` error with a message.
+    ///
+    /// Convenience wrapper around [`AppError::database`] for the common case
+    /// where you start from a plain string-like value.
+    ///
+    /// ```rust
+    /// use masterror::AppError;
+    ///
+    /// let err = AppError::database_with_message("db down");
+    /// assert_eq!(err.message.as_deref(), Some("db down"));
+    /// ```
+    pub fn database_with_message(msg: impl Into<Cow<'static, str>>) -> Self {
+        Self::database(Some(msg.into()))
+    }
     /// Build a `Config` error.
     pub fn config(msg: impl Into<Cow<'static, str>>) -> Self {
         Self::with(AppErrorKind::Config, msg)

src/app_error/tests.rs

@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use super::{AppResult, core::AppError};
 use crate::AppErrorKind;
 
@@ -108,10 +110,13 @@ fn constructors_match_kinds() {
 
 #[test]
 fn database_accepts_optional_message() {
-    let with_msg = AppError::database(Some("db down"));
+    let with_msg = AppError::database_with_message("db down");
     assert_err_with_msg(with_msg, AppErrorKind::Database, "db down");
 
-    let without = AppError::database(None::<&str>);
+    let via_option = AppError::database(Some(Cow::Borrowed("db down")));
+    assert_err_with_msg(via_option, AppErrorKind::Database, "db down");
+
+    let without = AppError::database(None);
     assert_err_bare(without, AppErrorKind::Database);
 }
 

src/convert/sqlx.rs

@@ -50,7 +50,7 @@ impl From<SqlxError> for AppError {
     fn from(err: SqlxError) -> Self {
         match err {
             SqlxError::RowNotFound => AppError::not_found("Record not found"),
-            other => AppError::database(Some(other.to_string()))
+            other => AppError::database_with_message(other.to_string())
         }
     }
 }
@@ -63,7 +63,7 @@ impl From<SqlxError> for AppError {
 #[cfg_attr(docsrs, doc(cfg(feature = "sqlx-migrate")))]
 impl From<MigrateError> for AppError {
     fn from(err: MigrateError) -> Self {
-        AppError::database(Some(err.to_string()))
+        AppError::database_with_message(err.to_string())
     }
 }