Fix flow errors from base/connection

react/features/base/connection/actionTypes.js

@@ -1,3 +1,5 @@
+// @flow
+
 /**
  * The type of (redux) action which signals that a connection disconnected.
  *

react/features/base/connection/functions.js

@@ -8,16 +8,16 @@ import { toState } from '../redux';
  *
  * @param {Function|Object} stateOrGetState - The redux state or redux's
  * {@code getState} function.
- * @returns {string|undefined}
+ * @returns {string}
  */
-export function getInviteURL(stateOrGetState: Function | Object): ?string {
+export function getInviteURL(stateOrGetState: Function | Object): string {
     const state = toState(stateOrGetState);
     const locationURL
         = state instanceof URL
             ? state
             : state['features/base/connection'].locationURL;
 
-    return locationURL ? getURLWithoutParams(locationURL).href : undefined;
+    return getURLWithoutParams(locationURL).href;
 }
 
 /**

react/features/base/connection/index.js

@@ -1,3 +1,5 @@
+// @flow
+
 export * from './actions';
 export * from './actionTypes';
 export * from './functions';