Refactor OAuth2 callback function and improve error logging for URL validation

src/api/admin.rs

@@ -415,7 +415,11 @@ struct OAuth2CallbackParams {
 }
 
 #[get("/oauth2/callback?<params..>")]
-async fn oauth2_callback(_token: AdminToken, params: OAuth2CallbackParams, conn: DbConn) -> Result<Html<String>, Error> {
+async fn oauth2_callback(
+    _token: AdminToken,
+    params: OAuth2CallbackParams,
+    conn: DbConn
+) -> Result<Html<String>, Error> {
     // Check for errors from OAuth2 provider
     if let Some(error) = params.error {
         let description = params.error_description.unwrap_or_else(|| "Unknown error".to_string());

src/config.rs

@@ -1296,9 +1296,7 @@ fn validate_config(cfg: &ConfigItems) -> Result<(), Error> {
                     }
                 }
                 Err(e) => {
-                    err!(format!(
+                    err!(format!("`SMTP_OAUTH2_AUTH_URL` must be a valid URL: '{e}'"));
-                        "`SMTP_OAUTH2_AUTH_URL` must be a valid URL: '{e}'"
-                    ));
                 }
             }
         }
@@ -1312,9 +1310,7 @@ fn validate_config(cfg: &ConfigItems) -> Result<(), Error> {
                     }
                 }
                 Err(e) => {
-                    err!(format!(
+                    err!(format!("`SMTP_OAUTH2_TOKEN_URL` must be a valid URL: '{e}'"));
-                        "`SMTP_OAUTH2_TOKEN_URL` must be a valid URL: '{e}'"
-                    ));
                 }
             }
         }