Fix tonic status conversion for Rust 1.90

CHANGELOG.md

@@ -3,6 +3,13 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+## [0.20.6] - 2025-10-06
+
+### Fixed
+- Restored compilation on Rust 1.90+ by aliasing the infallible gRPC
+  conversion error to `core::convert::Infallible` and re-exporting it without
+  exposing the private `convert::tonic` module.
+
 ## [0.20.5] - 2025-10-05
 
 ### Changed

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "masterror"
-version = "0.20.5"
+version = "0.20.6"
 rust-version = "1.90"
 edition = "2024"
 license = "MIT OR Apache-2.0"

README.md

@@ -71,9 +71,9 @@ The build script keeps the full feature snippet below in sync with
 
 ~~~toml
 [dependencies]
-masterror = { version = "0.20.5", default-features = false }
+masterror = { version = "0.20.6", default-features = false }
 # or with features:
-# masterror = { version = "0.20.5", features = [
+# masterror = { version = "0.20.6", features = [
 #   "axum", "actix", "openapi", "serde_json",
 #   "tracing", "metrics", "backtrace", "sqlx",
 #   "sqlx-migrate", "reqwest", "redis", "validator",
@@ -85,7 +85,6 @@ masterror = { version = "0.20.5", default-features = false }
 ---
 
 <details>
-
   <summary><b>Quick start</b></summary>
 
 Create an error:
@@ -378,143 +377,8 @@ assert_eq!(problem.grpc.expect("grpc").name, "UNAUTHENTICATED");
 ~~~
 
 </details>
-<details>
-  <summary><b>Web framework integrations</b></summary>
-
-<details>
-  <summary>Axum</summary>
-
-~~~rust
-// features = ["axum", "serde_json"]
-...
-    assert!(payload.is_object());
-
-    #[cfg(target_arch = "wasm32")]
-    {
-        if let Err(console_err) = err.log_to_browser_console() {
-            eprintln!(
-                "failed to log to browser console: {:?}",
-                console_err.context()
-            );
-        }
-    }
-
-    Ok(())
-}
-~~~
-
-- On non-WASM targets `log_to_browser_console` returns
-  `BrowserConsoleError::UnsupportedTarget`.
-- `BrowserConsoleError::context()` exposes optional browser diagnostics for
-  logging/telemetry when console logging fails.
-
-</details>
-
-</details>
-
-<details>
-  <summary><b>Feature flags</b></summary>
-
-- `axum` — IntoResponse integration with structured JSON bodies
-- `actix` — Actix Web ResponseError and Responder implementations
-- `openapi` — Generate utoipa OpenAPI schema for ErrorResponse
-- `serde_json` — Attach structured JSON details to AppError
-- `tracing` — Emit structured tracing events when errors are constructed
-- `metrics` — Increment `error_total{code,category}` counter for each AppError
-- `backtrace` — Capture lazy `Backtrace` snapshots when telemetry is flushed
-- `sqlx` — Classify sqlx_core::Error variants into AppError kinds
-- `sqlx-migrate` — Map sqlx::migrate::MigrateError into AppError (Database)
-- `reqwest` — Classify reqwest::Error as timeout/network/external API
-- `redis` — Map redis::RedisError into cache-aware AppError
-- `validator` — Convert validator::ValidationErrors into validation failures
-- `config` — Propagate config::ConfigError as configuration issues
-- `tokio` — Classify tokio::time::error::Elapsed as timeout
-- `multipart` — Handle axum multipart extraction errors
-- `teloxide` — Convert teloxide_core::RequestError into domain errors
-- `telegram-webapp-sdk` — Surface Telegram WebApp validation failures
-- `tonic` — Convert AppError into tonic::Status with redaction
-- `frontend` — Log to the browser console and convert to JsValue on WASM
-- `turnkey` — Ship Turnkey-specific error taxonomy and conversions
-
-</details>
-
-<details>
-  <summary><b>Conversions</b></summary>
-
-- `std::io::Error` → Internal
-- `String` → BadRequest
-- `sqlx::Error` → NotFound/Database
-- `redis::RedisError` → Cache
-- `reqwest::Error` → Timeout/Network/ExternalApi
-- `axum::extract::multipart::MultipartError` → BadRequest
-- `validator::ValidationErrors` → Validation
-- `config::ConfigError` → Config
-- `tokio::time::error::Elapsed` → Timeout
-- `teloxide_core::RequestError` → RateLimited/Network/ExternalApi/Deserialization/Internal
-- `telegram_webapp_sdk::utils::validate_init_data::ValidationError` → TelegramAuth
-
-</details>
-
-<details>
-  <summary><b>Typical setups</b></summary>
-
-Minimal core:
 
-~~~toml
-masterror = { version = "0.20.5", default-features = false }
-~~~
-
-API (Axum + JSON + deps):
-
-~~~toml
-masterror = { version = "0.20.5", features = [
-  "axum", "serde_json", "openapi",
-  "sqlx", "reqwest", "redis", "validator", "config", "tokio"
-] }
-~~~
-
-API (Actix + JSON + deps):
-
-~~~toml
-masterror = { version = "0.20.5", features = [
-  "actix", "serde_json", "openapi",
-  "sqlx", "reqwest", "redis", "validator", "config", "tokio"
-] }
-~~~
-
-</details>
-
-<details>
-  <summary><b>Turnkey</b></summary>
-
-~~~rust
-// features = ["turnkey"]
-use masterror::turnkey::{classify_turnkey_error, TurnkeyError, TurnkeyErrorKind};
-use masterror::{AppError, AppErrorKind};
-
-// Classify a raw SDK/provider error
-let kind = classify_turnkey_error("429 Too Many Requests");
-assert!(matches!(kind, TurnkeyErrorKind::RateLimited));
-
-// Wrap into AppError
-let e = TurnkeyError::new(TurnkeyErrorKind::RateLimited, "throttled upstream");
-let app: AppError = e.into();
-assert_eq!(app.kind, AppErrorKind::RateLimited);
-~~~
-
-</details>
-
-<details>
-  <summary><b>Migration 0.2 → 0.3</b></summary>
-
-- Use `ErrorResponse::new(status, AppCode::..., "msg")` instead of legacy
-- New helpers: `.with_retry_after_secs`, `.with_retry_after_duration`, `.with_www_authenticate`
-- `ErrorResponse::new_legacy` is temporary shim
-
-</details>
-
-<details>
-  <summary><b>Versioning & MSRV</b></summary>
+### Further resources
 
 - Explore the [error-handling wiki](docs/wiki/index.md) for step-by-step guides,
   comparisons with `thiserror`/`anyhow`, and troubleshooting recipes.

src/convert.rs

@@ -130,6 +130,9 @@ mod telegram_webapp_sdk;
 #[cfg_attr(docsrs, doc(cfg(feature = "tonic")))]
 mod tonic;
 
+#[cfg(feature = "tonic")]
+pub use self::tonic::StatusConversionError;
+
 /// Map `std::io::Error` to an internal application error.
 ///
 /// Rationale: I/O failures are infrastructure-level and should not leak

src/convert/tonic.rs

@@ -12,13 +12,14 @@
 //! ## Example
 //!
 //! ```rust,ignore
-//! use masterror::{AppError, AppErrorKind};
+//! use masterror::AppError;
 //!
 //! let status = tonic::Status::from(AppError::not_found("missing"));
 //! assert_eq!(status.code(), tonic::Code::NotFound);
 //! ```
 
-use std::{borrow::Cow, fmt};
+use core::convert::Infallible;
+use std::borrow::Cow;
 
 use tonic::{
     Code, Status,
@@ -32,52 +33,32 @@ use crate::{
     mapping_for_code
 };
 
-/// Error returned when converting [`Error`] into [`Status`] fails.
+/// Error alias retained for backwards compatibility with 0.20 conversions.
 ///
-/// This type is never constructed in practice because the conversion is
-/// guaranteed to succeed. It exists solely to preserve the `TryFrom` API in
-/// addition to the infallible [`From`] conversion.
+/// Since Rust 1.90 the standard library implements [`TryFrom`] for every
+/// [`Into`] conversion with [`core::convert::Infallible`] as the error type.
+/// Tonic conversions are therefore guaranteed to succeed, and this alias keeps
+/// the historic [`StatusConversionError`] name available for downstream APIs.
 ///
 /// # Examples
 /// ```rust,ignore
 /// use masterror::{AppError, StatusConversionError};
 /// use tonic::{Code, Status};
 ///
-/// fn convert() -> Result<Status, StatusConversionError> {
-///     Status::try_from(AppError::not_found("missing"))
-/// }
-///
-/// # fn main() -> Result<(), StatusConversionError> {
-/// let status = convert()?;
+/// let status: Result<Status, StatusConversionError> = Status::try_from(
+///     AppError::not_found("missing")
+/// );
+/// let status = status.expect("conversion cannot fail");
 /// assert_eq!(status.code(), Code::NotFound);
-/// # Ok(())
-/// # }
 /// ```
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub struct StatusConversionError;
-
-impl fmt::Display for StatusConversionError {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_str("conversion to tonic::Status cannot fail")
-    }
-}
-
-impl std::error::Error for StatusConversionError {}
+pub type StatusConversionError = Infallible;
 
 impl From<Error> for Status {
     fn from(error: Error) -> Self {
         status_from_error(&error)
     }
 }
 
-impl TryFrom<Error> for Status {
-    type Error = StatusConversionError;
-
-    fn try_from(error: Error) -> Result<Self, Self::Error> {
-        Ok(Status::from(error))
-    }
-}
-
 fn status_from_error(error: &Error) -> Status {
     error.emit_telemetry();
 

src/lib.rs

@@ -366,4 +366,4 @@ pub use result_ext::ResultExt;
 
 #[cfg(feature = "tonic")]
 #[cfg_attr(docsrs, doc(cfg(feature = "tonic")))]
-pub use crate::convert::tonic::StatusConversionError;
+pub use crate::convert::StatusConversionError;