feat(rpc): report JWT path in case of an IO read error (#3324)

Cargo.lock

@@ -5634,6 +5634,7 @@ dependencies = [
 name = "reth-rpc"
 version = "0.1.0-alpha.1"
 dependencies = [
+ "assert_matches",
  "async-trait",
  "bytes",
  "ethers-core",
@@ -5663,6 +5664,7 @@ dependencies = [
  "secp256k1",
  "serde",
  "serde_json",
+ "tempfile",
  "thiserror",
  "tokio",
  "tokio-stream",

crates/rpc/rpc/Cargo.toml

@@ -61,3 +61,5 @@ futures = { workspace = true }
 
 [dev-dependencies]
 jsonrpsee = { version = "0.18", features = ["client"] }
+assert_matches = "1.5.0"
+tempfile = "3.5.0"

crates/rpc/rpc/src/layers/jwt_secret.rs

@@ -3,7 +3,7 @@ use jsonwebtoken::{decode, errors::ErrorKind, Algorithm, DecodingKey, Validation
 use rand::Rng;
 use serde::{Deserialize, Serialize};
 use std::{
-    path::Path,
+    path::{Path, PathBuf},
     time::{Duration, SystemTime, UNIX_EPOCH},
 };
 use thiserror::Error;
@@ -26,6 +26,10 @@ pub enum JwtError {
     MissingOrInvalidAuthorizationHeader,
     #[error("JWT decoding error {0}")]
     JwtDecodingError(String),
+    #[error("IO error occurred while reading {path}: {err}")]
+    IORead { err: std::io::Error, path: PathBuf },
+    #[error("IO error occurred while writing {path}: {err}")]
+    IOWrite { err: std::io::Error, path: PathBuf },
     #[error("An I/O error occurred: {0}")]
     IOError(#[from] std::io::Error),
 }
@@ -76,7 +80,8 @@ impl JwtSecret {
     /// I/O or secret validation errors might occur during read operations in the form of
     /// a [`JwtError`].
     pub fn from_file(fpath: &Path) -> Result<Self, JwtError> {
-        let hex = std::fs::read_to_string(fpath)?;
+        let hex = std::fs::read_to_string(fpath)
+            .map_err(|err| JwtError::IORead { err, path: fpath.to_path_buf() })?;
         let secret = JwtSecret::from_hex(hex)?;
         Ok(secret)
     }
@@ -92,7 +97,8 @@ impl JwtSecret {
         let secret = JwtSecret::random();
         let bytes = &secret.0;
         let hex = hex::encode(bytes);
-        std::fs::write(fpath, hex)?;
+        std::fs::write(fpath, hex)
+            .map_err(|err| JwtError::IOWrite { err, path: fpath.to_path_buf() })?;
         Ok(secret)
     }
 }
@@ -195,12 +201,14 @@ impl Claims {
 mod tests {
     use super::{Claims, JwtError, JwtSecret};
     use crate::layers::jwt_secret::JWT_MAX_IAT_DIFF;
+    use assert_matches::assert_matches;
     use hex::encode as hex_encode;
     use jsonwebtoken::{encode, Algorithm, EncodingKey, Header};
     use std::{
         path::Path,
         time::{Duration, SystemTime, UNIX_EPOCH},
     };
+    use tempfile::tempdir;
 
     #[test]
     fn from_hex() {
@@ -367,10 +375,17 @@ mod tests {
     fn provided_file_not_exists() {
         let fpath = Path::new("secret3.hex");
         let result = JwtSecret::from_file(fpath);
-        assert!(result.is_err());
+        assert_matches!(result, Err(JwtError::IORead {err: _, path}) if path == fpath.to_path_buf());
         assert!(!exists(fpath));
     }
 
+    #[test]
+    fn provided_file_is_a_directory() {
+        let dir = tempdir().unwrap();
+        let result = JwtSecret::from_file(dir.path());
+        assert_matches!(result, Err(JwtError::IORead {err: _, path}) if path == dir.into_path());
+    }
+
     fn hex(secret: &JwtSecret) -> String {
         hex::encode(secret.0)
     }