Better settings handling with localSettings (new!)

app/javascript/mastodon/reducers/local_settings.js

@@ -0,0 +1,20 @@
+import { LOCAL_SETTING_CHANGE } from '../actions/local_settings';
+import { STORE_HYDRATE } from '../actions/store';
+import Immutable from 'immutable';
+
+const initialState = Immutable.Map({
+  layout: 'auto',
+});
+
+const hydrate = (state, localSettings) => state.mergeDeep(localSettings);
+
+export default function localSettings(state = initialState, action) {
+  switch(action.type) {
+  case STORE_HYDRATE:
+    return hydrate(state, action.state.get('localSettings'));
+  case LOCAL_SETTING_CHANGE:
+    return state.setIn(action.key, action.value);
+  default:
+    return state;
+  }
+};