Allow overriding partial state via hash

js/store.js

@@ -3,12 +3,21 @@ import reducer from "./reducers";
 import thunk from "redux-thunk";
 import { composeWithDevTools } from "redux-devtools-extension";
 import mediaMiddleware from "./mediaMiddleware";
+import { merge } from "./utils";
 
-const getStore = (winamp, initialState) =>
-  createStore(
+const getStore = (winamp, stateOverrides) => {
+  let initialState;
+  if (stateOverrides) {
+    initialState = merge(
+      reducer(undefined, { type: "@@init" }),
+      stateOverrides
+    );
+  }
+  return createStore(
     reducer,
     initialState,
     composeWithDevTools(applyMiddleware(thunk, mediaMiddleware(winamp.media)))
   );
+};
 
 export default getStore;

js/utils.js

@@ -78,3 +78,16 @@ export const normalize = rebound(1, 64, 1, 100);
 
 // Convert a 0-100 to an .eqf value
 export const denormalize = rebound(1, 100, 1, 64);
+
+// Merge a `source` object to a `target` recursively
+export const merge = (target, source) => {
+  // Iterate through `source` properties and if an `Object` set property to merge of `target` and `source` properties
+  for (const key of Object.keys(source)) {
+    if (source[key] instanceof Object)
+      Object.assign(source[key], merge(target[key], source[key]));
+  }
+
+  // Join `target` and modified `source`
+  Object.assign(target || {}, source);
+  return target;
+};