Extract getCompanionWindowLocale selector.

Author: cbeer

src/state/selectors/companionWindows.js

@@ -29,6 +29,18 @@ export const getCompanionWindow = createSelector(
   (companionWindows, companionWindowId) => companionWindowId && companionWindows[companionWindowId],
 );
 
+/**
+ * Returns the companion window locale.
+ * @param {object} state
+ * @param {object} props
+ * @param {string} props.companionWindowId
+ * @returns {string|undefined}
+ */
+export const getCompanionWindowLocale = createSelector(
+  [getCompanionWindow],
+  companionWindow => companionWindow && companionWindow.locale,
+);
+
 /**
  * Return position of thumbnail navigation in a certain window.
  * @param {object} state

src/state/selectors/manifests.js

@@ -3,7 +3,7 @@ import { createCachedSelector } from 're-reselect';
 import { PropertyValue, Utils, Resource } from 'manifesto.js';
 import getThumbnail from '../../lib/ThumbnailFactory';
 import asArray from '../../lib/asArray';
-import { getCompanionWindow } from './companionWindows';
+import { getCompanionWindowLocale } from './companionWindows';
 import { getManifest } from './getters';
 import { getConfig } from './config';
 
@@ -22,11 +22,11 @@ function createManifestoInstance(json, locale) {
 /** */
 export const getLocale = createSelector(
   [
-    getCompanionWindow,
+    getCompanionWindowLocale,
     getConfig,
   ],
-  (companionWindow = {}, config = {}) => (
-    companionWindow.locale || config.language
+  (companionWindowLocale, config = {}) => (
+    companionWindowLocale || config.language
   ),
 );