Update path of mergeState, assuming observable definition

client/src/store.js

@@ -3,8 +3,15 @@ export const createStore = (initial, actions = {}) => {
   const hooks = {};
 
   const mergeState = newState => {
-    // TODO
-  }
+    Object.entries(newState).forEach(([key, newValue]) => {
+      const obs = store[key];
+      if (obs) {
+        obs._set(newValue);
+      } else {
+        // TODO
+      }
+    });
+  };
 
   mergeState(initial);