refactor(server,common): introduce custom error types with thiserror and miette

Cargo.lock

@@ -275,11 +275,15 @@ name = "common"
 version = "0.1.0"
 dependencies = [
  "cargo-husky",
+ "miette",
  "rcgen",
+ "rustls",
  "serde",
  "serde_json",
  "strum",
+ "thiserror",
  "tokio",
+ "toml",
 ]
 
 [[package]]
@@ -915,6 +919,7 @@ dependencies = [
  "common",
  "miette",
  "rustls",
+ "thiserror",
  "tokio",
  "tokio-rustls",
  "tracing",

common/Cargo.toml

@@ -5,11 +5,15 @@ authors.workspace = true
 edition.workspace = true
 
 [dependencies]
+miette.workspace = true
 rcgen.workspace = true
+rustls.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 strum.workspace = true
+thiserror.workspace = true
 tokio.workspace = true
+toml.workspace = true
 
 [dev-dependencies]
 cargo-husky.workspace = true

common/src/error.rs

@@ -0,0 +1,65 @@
+use miette::Diagnostic;
+use thiserror::Error;
+
+/// Result type using the common's custom error type.
+pub type Result<T> = std::result::Result<T, Error>;
+
+#[derive(Debug, Error, Diagnostic)]
+pub enum Error {
+    /// File or network I/O error.
+    #[error(transparent)]
+    #[diagnostic(code(common::io_error))]
+    Io(#[from] std::io::Error),
+
+    #[error(transparent)]
+    #[diagnostic(code(common::rustls_error))]
+    Tls(#[from] rustls::Error),
+
+    /// TOML configuration file parse error.
+    #[error(transparent)]
+    #[diagnostic(code(common::toml_error))]
+    Toml(#[from] toml::de::Error),
+
+    #[error(transparent)]
+    #[diagnostic(code(common::json_error))]
+    Json(#[from] serde_json::Error),
+
+    #[error(transparent)]
+    #[diagnostic(code(common::rcgen_error))]
+    RCGen(#[from] rcgen::Error),
+
+    /// Configuration validation or missing required fields.
+    #[error("Config error: {0}")]
+    #[diagnostic(code(common::config_error))]
+    Config(String),
+
+    /// Invalid key exchange mode string.
+    #[error("Invalid mode: {0}")]
+    #[diagnostic(code(common::invalid_mode))]
+    InvalidMode(String),
+
+    /// Protocol-level error (malformed requests, unexpected responses).
+    #[error("Protocol error: {0}")]
+    #[diagnostic(code(common::protocol_error))]
+    Protocol(String),
+}
+
+impl Error {
+    /// Create an invalid mode error.
+    #[inline]
+    pub fn invalid_mode(error: impl Into<String>) -> Self {
+        Self::InvalidMode(error.into())
+    }
+
+    /// Create a config error.
+    #[inline]
+    pub fn config(error: impl Into<String>) -> Self {
+        Self::Config(error.into())
+    }
+
+    /// Create a protocol error.
+    #[inline]
+    pub fn protocol(error: impl Into<String>) -> Self {
+        Self::Protocol(error.into())
+    }
+}

common/src/lib.rs

@@ -1,8 +1,10 @@
 //! Common types and utilities for the TLS benchmark harness.
 
 pub mod cert;
+pub mod error;
 pub mod protocol;
 
+pub use error::Error;
 use serde::{Deserialize, Serialize};
 use std::fmt;
 use strum::{Display, EnumString};

runner/src/config.rs

@@ -1,5 +1,5 @@
 use crate::{args::Args, error};
-use common::KeyExchangeMode;
+use common::{self, KeyExchangeMode};
 use serde::Deserialize;
 use std::{fs::read_to_string, net::SocketAddr, path::PathBuf};
 
@@ -23,8 +23,8 @@ pub struct Config {
 /// # Errors
 /// Returns an error if the file cannot be read or parsed.
 pub fn load_from_file(path: &PathBuf) -> error::Result<Config> {
-    let content = read_to_string(path).map_err(error::Error::Io)?;
-    let config = toml::from_str::<Config>(&content).map_err(error::Error::Toml)?;
+    let content = read_to_string(path).map_err(common::Error::Io)?;
+    let config = toml::from_str::<Config>(&content).map_err(common::Error::Toml)?;
     Ok(config)
 }
 
@@ -42,7 +42,7 @@ pub fn load_from_cli(args: &Args) -> error::Result<Config> {
             concurrency: args.concurrency,
             server: args
                 .server
-                .ok_or_else(|| error::Error::config("--server ir required"))?,
+                .ok_or_else(|| common::Error::config("--server ir required"))?,
         }],
     })
 }

runner/src/error.rs

@@ -9,64 +9,20 @@ pub type Result<T> = std::result::Result<T, Error>;
 /// Errors that can occur during benchmark execution.
 #[derive(Debug, Error, Diagnostic)]
 pub enum Error {
-    /// TLS configuration or handshake failure.
     #[error(transparent)]
-    #[diagnostic(code(runner::tls_error))]
-    TlsConfig(#[from] rustls::Error),
-
-    /// File or network I/O error.
-    #[error(transparent)]
-    #[diagnostic(code(runner::io_error))]
-    Io(#[from] std::io::Error),
-
-    /// TOML configuration file parse error.
-    #[error(transparent)]
-    #[diagnostic(code(runner::toml_error))]
-    Toml(#[from] toml::de::Error),
-
-    /// Invalid key exchange mode string.
-    #[error("Invalid mode: {0}")]
-    #[diagnostic(code(runner::invalid_mode))]
-    InvalidMode(String),
-
-    /// Configuration validation or missing required fields.
-    #[error("Config error: {0}")]
-    #[diagnostic(code(runner::config_error))]
-    Config(String),
+    #[diagnostic(code(runner::common_error))]
+    Common(#[from] common::Error),
 
     /// Network connection failure.
     #[error("Network error: {0}")]
     #[diagnostic(code(runner::network_error))]
     Network(String),
-
-    /// Protocol-level error (malformed requests, unexpected responses).
-    #[error("Protocol error: {0}")]
-    #[diagnostic(code(runner::protocol_error))]
-    Protocol(String),
 }
 
 impl Error {
-    /// Create an invalid mode error.
-    #[inline]
-    pub fn invalid_mode(error: impl Into<String>) -> Self {
-        Self::InvalidMode(error.into())
-    }
-
-    /// Create a config error.
-    #[inline]
-    pub fn config(error: impl Into<String>) -> Self {
-        Self::Config(error.into())
-    }
-
     /// Create a network error.
     #[inline]
     pub fn network(error: impl Into<String>) -> Self {
         Self::Network(error.into())
     }
-
-    /// Create a protocol error.
-    #[inline]
-    pub fn protocol(error: impl Into<String>) -> Self {
-        Self::Protocol(error.into())
-    }
 }

server/Cargo.toml

@@ -10,10 +10,11 @@ clap.workspace = true
 common.workspace = true
 miette.workspace = true
 rustls.workspace = true
+thiserror.workspace = true
 tokio-rustls.workspace = true
 tokio.workspace = true
-tracing.workspace = true
 tracing-subscriber.workspace = true
+tracing.workspace = true
 uuid.workspace = true
 
 [lints]

server/src/error.rs

@@ -0,0 +1,38 @@
+use miette::Diagnostic;
+use thiserror::Error;
+
+/// Result type using the servers's custom error type.
+pub type Result<T> = std::result::Result<T, Error>;
+
+#[derive(Debug, Error, Diagnostic)]
+pub enum Error {
+    #[error(transparent)]
+    #[diagnostic(code(runner::common_error))]
+    Common(#[from] common::Error),
+
+    #[error(transparent)]
+    #[diagnostic(code(server::cert_validation_error))]
+    CertValidation(#[from] rustls::pki_types::InvalidDnsNameError),
+
+    /// Network connection failure.
+    #[error("Network error: {0}")]
+    #[diagnostic(code(server::network_error))]
+    Network(String),
+
+    #[error("Invalid certificate: {0}")]
+    #[diagnostic(code(server::invalid_cert))]
+    InvalidCert(String),
+}
+
+impl Error {
+    /// Create a network error.
+    #[inline]
+    pub fn network(error: impl Into<String>) -> Self {
+        Self::Network(error.into())
+    }
+
+    #[inline]
+    pub fn invalid_cert(error: impl Into<String>) -> Self {
+        Self::InvalidCert(error.into())
+    }
+}

server/src/lib.rs

@@ -0,0 +1 @@
+pub mod error;

server/src/main.rs

@@ -4,6 +4,8 @@
 //! - Reads 8-byte little-endian u64 (requested payload size N)
 //! - Responds with exactly N bytes (deterministic pattern)
 
+mod error;
+
 use base64::prelude::*;
 use clap::Parser;
 use common::{
@@ -11,7 +13,6 @@ use common::{
     cert::{CaCertificate, ServerCertificate},
     protocol::{read_request, write_payload},
 };
-use miette::miette;
 use rustls::{
     ServerConfig,
     crypto::aws_lc_rs::{
@@ -48,7 +49,7 @@ struct Args {
 fn build_tls_config(
     mode: KeyExchangeMode,
     server_cert: &ServerCertificate,
-) -> miette::Result<Arc<ServerConfig>> {
+) -> error::Result<Arc<ServerConfig>> {
     let mut provider = aws_lc_rs::default_provider();
     provider.kx_groups = match mode {
         KeyExchangeMode::X25519 => vec![X25519],
@@ -62,14 +63,14 @@ fn build_tls_config(
         .collect::<Vec<_>>();
 
     let key = PrivateKeyDer::try_from(server_cert.private_key_der.clone())
-        .map_err(|e| miette!("invalid private key: {e}"))?;
+        .map_err(|e| error::Error::invalid_cert(format!("invalid private_key: {e}")))?;
 
     let config = ServerConfig::builder_with_provider(Arc::new(provider))
         .with_protocol_versions(&[&TLS13])
-        .map_err(|e| miette!("failed to set TLS versions: {e}"))?
+        .map_err(common::Error::Tls)?
         .with_no_client_auth()
         .with_single_cert(certs, key)
-        .map_err(|e| miette!("failed to configure certificate: {e}"))?;
+        .map_err(common::Error::Tls)?;
 
     Ok(Arc::new(config))
 }
@@ -123,10 +124,10 @@ async fn handle_connection(stream: TcpStream, peer: SocketAddr, tls_config: Arc<
     }
 }
 
-async fn run_server(args: Args, tls_config: Arc<ServerConfig>) -> miette::Result<()> {
+async fn run_server(args: Args, tls_config: Arc<ServerConfig>) -> error::Result<()> {
     let listener = TcpListener::bind(args.listen)
         .await
-        .map_err(|e| miette!("failed to bind to {}: {e}", args.listen))?;
+        .map_err(|e| error::Error::network(format!("failed to bind to {}: {e}", args.listen)))?;
 
     info!(listen = %args.listen, mode = %args.mode, "listening");
 
@@ -164,10 +165,10 @@ async fn main() -> miette::Result<()> {
     );
 
     info!("Generating self-signed certificates...");
-    let ca = CaCertificate::generate().map_err(|e| miette!("failed to generate CA: {e}"))?;
+    let ca = CaCertificate::generate().map_err(common::Error::RCGen)?;
     let server_cert = ca
         .sign_server_cert("localhost")
-        .map_err(|e| miette!("failed to generate server cert: {e}"))?;
+        .map_err(common::Error::RCGen)?;
 
     let tls_config = build_tls_config(args.mode, &server_cert)?;
 
@@ -180,5 +181,5 @@ async fn main() -> miette::Result<()> {
         "CA cert (truncated)"
     );
 
-    run_server(args, tls_config).await
+    Ok(run_server(args, tls_config).await?)
 }