typing: Serialize recipients based on server version.

Zulip server versions >= 2.0.0-rc1 require user ID arrays in the
'to' argument for the typing endpoint, whereas we currently send
email arrays.

Check the Zulip version and use the appropriate format of the
argument, i.e., for versions >= 2.0.0-rc1 or when the Zulip server
version is undetermined, use user ID arrays, otherwise, use email
arrays.

Fixes #3732.

Author: agrawal-d

src/users/usersActions.js

@@ -1,12 +1,13 @@
 /* @flow strict-local */
 import * as typing_status from '@zulip/shared/js/typing_status';
 
-import type { Dispatch, GetState, Narrow } from '../types';
+import type { Auth, Account, Dispatch, GetState, GlobalState, Narrow } from '../types';
 import * as api from '../api';
 import { PRESENCE_RESPONSE } from '../actionConstants';
-import { getAuth, tryGetAuth } from '../selectors';
+import { getAuth, tryGetAuth, tryGetActiveAccount } from '../selectors';
 import { isPrivateOrGroupNarrow, caseNarrowPartial } from '../utils/narrow';
-import { getAllUsersByEmail } from './userSelectors';
+import { getAllUsersByEmail, getUserForId } from './userSelectors';
+import { ZulipVersion } from '../utils/zulipVersion';
 
 export const reportPresence = (isActive: boolean = true, newUserInput: boolean = false) => async (
   dispatch: Dispatch,
@@ -25,17 +26,42 @@ export const reportPresence = (isActive: boolean = true, newUserInput: boolean =
   });
 };
 
-const typingWorker = auth => ({
-  get_current_time: () => new Date().getTime(),
+const typingWorker = (state: GlobalState) => {
+  const auth: Auth = getAuth(state);
 
-  notify_server_start: (user_ids_array: number[]) => {
-    api.typing(auth, JSON.stringify(user_ids_array), 'start');
-  },
+  // User ID arrays are only supported in server versions >= 2.0.0-rc1, for
+  // versions before this, email arrays are used. If current server version is
+  // undetermined, user ID arrays are optimistically used.
+  let useEmailArrays: boolean;
+  const activeAccount: Account | void = tryGetActiveAccount(state);
 
-  notify_server_stop: (user_ids_array: number[]) => {
-    api.typing(auth, JSON.stringify(user_ids_array), 'stop');
-  },
-});
+  if (!activeAccount || activeAccount.zulipVersion === undefined) {
+    useEmailArrays = false;
+  } else {
+    useEmailArrays = !new ZulipVersion(activeAccount.zulipVersion).isAtLeast(
+      new ZulipVersion('2.0.0-rc1'),
+    );
+  }
+
+  const getRecipients = user_ids_array => {
+    if (useEmailArrays) {
+      return JSON.stringify(user_ids_array.map(userId => getUserForId(state, userId).email));
+    }
+    return JSON.stringify(user_ids_array);
+  };
+
+  return {
+    get_current_time: () => new Date().getTime(),
+
+    notify_server_start: (user_ids_array: number[]) => {
+      api.typing(auth, getRecipients(user_ids_array), 'start');
+    },
+
+    notify_server_stop: (user_ids_array: number[]) => {
+      api.typing(auth, getRecipients(user_ids_array), 'stop');
+    },
+  };
+};
 
 export const sendTypingStart = (narrow: Narrow) => async (
   dispatch: Dispatch,
@@ -56,9 +82,7 @@ export const sendTypingStart = (narrow: Narrow) => async (
     }
     return user.user_id;
   });
-
-  const auth = getAuth(getState());
-  typing_status.update(typingWorker(auth), recipientIds);
+  typing_status.update(typingWorker(getState()), recipientIds);
 };
 
 // TODO call this on more than send: blur, navigate away,
@@ -71,6 +95,5 @@ export const sendTypingStop = (narrow: Narrow) => async (
     return;
   }
 
-  const auth = getAuth(getState());
-  typing_status.update(typingWorker(auth), null);
+  typing_status.update(typingWorker(getState()), null);
 };