fix(multi-sheet-tab): update last xml on content changed

client/src/app/App.js

@@ -216,6 +216,7 @@ export class App extends Component {
 
       await this.workspaceChanged();
       await this.handleTabChanged(tab)();
+      await this.tabRef.current.triggerAction('set-last-xml', updatedFile.contents);
     }
 
   }

client/src/app/__tests__/AppSpec.js

@@ -1314,7 +1314,7 @@ describe('<App>', function() {
           dialog,
           fileSystem
         }
-      });
+      }, mount);
 
       const openedTabs = await app.openFiles([ file1, file2 ]);
 

client/src/app/tabs/MultiSheetTab.js

@@ -206,6 +206,11 @@ export class MultiSheetTab extends CachedComponent {
       const { fileType } = options;
 
       return await editor.exportAs(fileType);
+    } else if (action === 'set-last-xml') {
+
+      this.setCached({
+        lastXML: options.xml
+      });
     }
 
     return editor.triggerAction(action, options);