actionTypes: Make recipients and sender exact on `EventTypingComm…

…on`.

The doc, at https://zulip.com/api/get-events, suggests that these
types already include all fields that will be present. So, make them
exact.

An instance of zulip#3452.

src/actionTypes.js

@@ -377,14 +377,14 @@ type EventPresenceAction = {|
 type EventTypingCommon = {|
   ...ServerEvent,
   ownUserId: UserId,
-  recipients: $ReadOnlyArray<{
+  recipients: $ReadOnlyArray<{|
     user_id: UserId,
     email: string,
-  }>,
-  sender: {
+  |}>,
+  sender: {|
     user_id: UserId,
     email: string,
-  },
+  |},
   time: number,
 |};
 

src/typing/__tests__/typingReducer-test.js

@@ -20,7 +20,13 @@ describe('typingReducer', () => {
     time: number,
   |}): Action => {
     const { op, sender, recipients, time } = args;
-    const base = { id: 123, ownUserId: eg.selfUser.user_id, sender, recipients, time };
+    const base = {
+      id: 123,
+      ownUserId: eg.selfUser.user_id,
+      sender: { user_id: sender.user_id, email: sender.email },
+      recipients: recipients.map(r => ({ user_id: r.user_id, email: r.email })),
+      time,
+    };
     return op === 'start'
       ? { ...base, op: 'start', type: EVENT_TYPING_START }
       : { ...base, op: 'stop', type: EVENT_TYPING_STOP };