Fixed broken navigation plugin

Summary: The navigation plugin threw exceptions, as the defaultPersisted state was not mixed into the already stored state, making some fields unreadable

Reviewed By: jknoxville

Differential Revision: D19554291

fbshipit-source-id: 57f045aa1eae10682e44d479b9aecb51f0391b9e

src/utils/messageQueue.tsx

@@ -143,10 +143,7 @@ export function processMessageImmediately(
   },
   message: {method: string; params?: any},
 ) {
-  const persistedState: any =
-    store.getState().pluginStates[pluginKey] ??
-    plugin.defaultPersistedState ??
-    {};
+  const persistedState = getCurrentPluginState(store, plugin, pluginKey);
   const newPluginState = processMessage(
     persistedState,
     pluginKey,
@@ -217,10 +214,7 @@ export async function processMessageQueue(
       break;
     }
     // there are messages to process! lets do so until we have to idle
-    const persistedState =
-      store.getState().pluginStates[pluginKey] ??
-      plugin.defaultPersistedState ??
-      {};
+    const persistedState = getCurrentPluginState(store, plugin, pluginKey);
     let offset = 0;
     let newPluginState = persistedState;
     do {
@@ -267,3 +261,15 @@ function getPendingMessages(
 ): Message[] {
   return store.getState().pluginMessageQueue[pluginKey] || [];
 }
+
+function getCurrentPluginState(
+  store: MiddlewareAPI,
+  plugin: {defaultPersistedState: any},
+  pluginKey: string,
+) {
+  // possible optimization: don't spread default state here by put proper default state when initializing clients
+  return {
+    ...plugin.defaultPersistedState,
+    ...store.getState().pluginStates[pluginKey],
+  };
+}