Fix serializeState option

Related to #253.

Author: zalmoxisus

src/app/api/index.js

@@ -9,7 +9,7 @@ function stringify(obj, serialize) {
   }
   if (serialize === true) {
     return jsan.stringify(obj, function(key, value) {
-      if (typeof value === 'object' && typeof value.toJS === 'function') return value.toJS();
+      if (value && typeof value.toJS === 'function') return value.toJS();
       if (typeof value === 'symbol') return String(value);
       return value;
     }, null, true);

src/browser/extension/inject/pageScript.js

@@ -54,12 +54,12 @@ const devToolsExtension = function(reducer, preloadedState, config) {
     actionSanitizer = actionsFilter; // eslint-disable-line no-param-reassign
   }
 
-  if (config.serializeState) {
+  if (typeof config.serializeState !== 'undefined') {
     serializeState = config.serializeState;
     if (typeof serializeState === 'function') serializeState = { replacer: serializeState };
     else shouldSerialize = true;
   }
-  if (config.serializeAction) {
+  if (typeof config.serializeAction !== 'undefined') {
     serializeAction = config.serializeAction;
     if (typeof serializeAction === 'function') serializeAction = { replacer: serializeAction };
     else shouldSerialize = true;