Add new test for client configuration

src/tcp_relay_client/client_config.rs

@@ -1,3 +1,4 @@
+use crate::base::err_utils::encpasulate_error;
 use bytes::BufMut;
 use clap::Parser;
 
@@ -45,21 +46,13 @@ pub struct KeysCache {
 
 impl ClientConfig {
     /// Load certificates and put them in cache
-    pub fn load_certificates(&mut self) {
+    pub fn load_certificates(&mut self) -> std::io::Result<()> {
         self._keys_cache = KeysCache {
-            _root_certificate_cache: self
-                .root_certificate
-                .as_ref()
-                .map(|c| std::fs::read(c).expect("Failed to read root certificate!")),
-            _tls_cert_cache: self
-                .tls_cert
-                .as_ref()
-                .map(|c| std::fs::read(c).expect("Failed to read client certificate!")),
-            _tls_key_cache: self
-                .tls_key
-                .as_ref()
-                .map(|c| std::fs::read(c).expect("Failed to read client key!")),
+            _root_certificate_cache: load_pem_file(&self.root_certificate, "root certificate")?,
+            _tls_cert_cache: load_pem_file(&self.tls_cert, "client certificate")?,
+            _tls_key_cache: load_pem_file(&self.tls_cert, "client key")?,
         };
+        Ok(())
     }
 
     /// Get client token, returning a dummy token if none was specified
@@ -95,6 +88,16 @@ impl ClientConfig {
     }
 }
 
+fn load_pem_file(path: &Option<String>, name: &str) -> std::io::Result<Option<Vec<u8>>> {
+    Ok(match path {
+        None => None,
+        Some(p) => Some(
+            std::fs::read(p)
+                .map_err(|e| encpasulate_error(e, format!("Failed to load {}!", name)))?,
+        ),
+    })
+}
+
 #[cfg(test)]
 mod test {
     use crate::tcp_relay_client::client_config::ClientConfig;