Make config extensions resilient

Author: martpie

src-tauri/src/libs/init.rs

@@ -26,11 +26,14 @@ pub fn init() -> AnyResult<ConfigManager> {
     let existing_config = manager.toml::<Config>();
 
     let config = match existing_config {
-        Ok(config) => ConfigManager::new(manager, config),
+        Ok(config) => {
+            // Backfill any missing keys populated by serde defaults.
+            manager.save_toml(&config).unwrap();
+
+            ConfigManager::new(manager, config)
+        }
         Err(_) => {
             // The config does not exist, so let's instantiate it with defaults
-            // Potential issue: if the config is extended, the defaults will be
-            // reloaded
             let default_config = Config::default();
             manager.save_toml(&default_config).unwrap();
 

src-tauri/src/plugins/config.rs

@@ -55,6 +55,7 @@ pub enum TrackViewDensity {
 
 #[derive(Serialize, Deserialize, Debug, Clone, TS)]
 #[ts(export, export_to = "../../src/generated/typings.ts")]
+#[serde(default)]
 pub struct Config {
     pub language: String,
     pub theme: String,
@@ -80,8 +81,8 @@ pub struct Config {
 
 pub const SYSTEM_THEME: &str = "__system";
 
-impl Config {
-    pub fn default() -> Self {
+impl Default for Config {
+    fn default() -> Self {
         Config {
             language: "en".to_owned(),
             theme: SYSTEM_THEME.to_owned(),