model: Fix lots of reducers that weren't clearing data on LOGIN_SUCCESS

Most of these state subtrees hold per-account data we get from the
server. In the current pre-zulip#5005 design, where we only store server
data for one account, these should already have been clearing out on
LOGIN_SUCCESS, like we do with messages, narrows, etc.

Two of the subtrees, `outbox` and `drafts`, hold client-side
per-account data. Just as with server data, we've only been keeping
these around for the active account, and like the other reducers
touched in this commit, we've forgotten to handle LOGIN_SUCCESS for
them. So, do that.

Now, all the server-data subtrees and `outbox` and `drafts` all
reset on ACCOUNT_SWITCH, LOGIN_SUCCESS, and LOGOUT. That's part of
Greg's proposed fix for zulip#4446.

Next, we'll do the next part:

> * I think it'd be a useful refactor to consolidate one action type
>   like `CLEAR_ACCOUNT_DATA`.
>   * The action creators for these three (in `accountActions.js`) can
>     dispatch that first, then also a `LOGOUT` etc.
>   * Almost all the reducers would respond only to the
>     `CLEAR_ACCOUNT_DATA`.
>   * There are a couple of exceptions, like `accountReducers` and
>     `sessionReducers`, that actually want to treat the three cases
>     differently. Those would be the only ones to continue responding
>     to `LOGOUT` etc.; and they'd stand out better as a result.
>   * Then there are further changes we might make to those, but
>     that'll be easier to see after that.

Fixes-partly: zulip#4446

src/alertWords/alertWordsReducer.js

@@ -1,6 +1,12 @@
 /* @flow strict-local */
 import type { AlertWordsState, PerAccountApplicableAction } from '../types';
-import { REGISTER_COMPLETE, EVENT_ALERT_WORDS, ACCOUNT_SWITCH, LOGOUT } from '../actionConstants';
+import {
+  REGISTER_COMPLETE,
+  EVENT_ALERT_WORDS,
+  ACCOUNT_SWITCH,
+  LOGOUT,
+  LOGIN_SUCCESS,
+} from '../actionConstants';
 import { NULL_ARRAY } from '../nullObjects';
 
 const initialState = NULL_ARRAY;
@@ -12,6 +18,7 @@ export default (
   switch (action.type) {
     case LOGOUT:
     case ACCOUNT_SWITCH:
+    case LOGIN_SUCCESS:
       return initialState;
 
     case REGISTER_COMPLETE:

src/drafts/draftsReducer.js

@@ -1,6 +1,6 @@
 /* @flow strict-local */
 import type { DraftsState, PerAccountApplicableAction } from '../types';
-import { DRAFT_UPDATE, LOGOUT, ACCOUNT_SWITCH } from '../actionConstants';
+import { DRAFT_UPDATE, LOGOUT, ACCOUNT_SWITCH, LOGIN_SUCCESS } from '../actionConstants';
 import { NULL_OBJECT } from '../nullObjects';
 import { keyFromNarrow } from '../utils/narrow';
 
@@ -29,6 +29,7 @@ export default (
   switch (action.type) {
     case LOGOUT:
     case ACCOUNT_SWITCH:
+    case LOGIN_SUCCESS:
       return initialState;
 
     case DRAFT_UPDATE:

src/mute/muteModel.js

@@ -1,7 +1,13 @@
 /* @flow strict-local */
 
 import type { MuteState, PerAccountApplicableAction, PerAccountState } from '../types';
-import { REGISTER_COMPLETE, LOGOUT, ACCOUNT_SWITCH, EVENT_MUTED_TOPICS } from '../actionConstants';
+import {
+  REGISTER_COMPLETE,
+  LOGOUT,
+  ACCOUNT_SWITCH,
+  EVENT_MUTED_TOPICS,
+  LOGIN_SUCCESS,
+} from '../actionConstants';
 import { getStreamsByName } from '../subscriptions/subscriptionSelectors';
 import * as logging from '../utils/logging';
 import DefaultMap from '../utils/DefaultMap';
@@ -49,6 +55,7 @@ export const reducer = (
   switch (action.type) {
     case LOGOUT:
     case ACCOUNT_SWITCH:
+    case LOGIN_SUCCESS:
       return initialState;
 
     case REGISTER_COMPLETE:

src/outbox/outboxReducer.js

@@ -8,6 +8,7 @@ import {
   ACCOUNT_SWITCH,
   DELETE_OUTBOX_MESSAGE,
   MESSAGE_SEND_COMPLETE,
+  LOGIN_SUCCESS,
 } from '../actionConstants';
 import { NULL_ARRAY } from '../nullObjects';
 import { filterArray } from '../utils/immutability';
@@ -44,6 +45,7 @@ export default (
 
     case ACCOUNT_SWITCH:
     case LOGOUT:
+    case LOGIN_SUCCESS:
       return initialState;
 
     default:

src/streams/streamsReducer.js

@@ -3,7 +3,13 @@ import { EventTypes } from '../api/eventTypes';
 import type { PerAccountApplicableAction, StreamsState, StreamUpdateEvent } from '../types';
 import type { Stream, Subscription } from '../api/modelTypes';
 import { ensureUnreachable } from '../types';
-import { LOGOUT, ACCOUNT_SWITCH, EVENT, REGISTER_COMPLETE } from '../actionConstants';
+import {
+  LOGOUT,
+  ACCOUNT_SWITCH,
+  EVENT,
+  REGISTER_COMPLETE,
+  LOGIN_SUCCESS,
+} from '../actionConstants';
 import { NULL_ARRAY } from '../nullObjects';
 import { filterArray } from '../utils/immutability';
 
@@ -61,6 +67,7 @@ export default (
 
     case LOGOUT:
     case ACCOUNT_SWITCH:
+    case LOGIN_SUCCESS:
       return initialState;
 
     case EVENT: {

src/topics/topicsReducer.js

@@ -1,6 +1,12 @@
 /* @flow strict-local */
 import type { TopicsState, PerAccountApplicableAction } from '../types';
-import { LOGOUT, ACCOUNT_SWITCH, INIT_TOPICS, EVENT_NEW_MESSAGE } from '../actionConstants';
+import {
+  LOGOUT,
+  ACCOUNT_SWITCH,
+  INIT_TOPICS,
+  EVENT_NEW_MESSAGE,
+  LOGIN_SUCCESS,
+} from '../actionConstants';
 import { NULL_OBJECT } from '../nullObjects';
 import { replaceItemInArray } from '../utils/immutability';
 
@@ -43,6 +49,7 @@ export default (
   switch (action.type) {
     case LOGOUT:
     case ACCOUNT_SWITCH:
+    case LOGIN_SUCCESS:
       return initialState;
 
     case INIT_TOPICS:

src/unread/unreadHuddlesReducer.js

@@ -10,6 +10,7 @@ import {
   EVENT_NEW_MESSAGE,
   EVENT_MESSAGE_DELETE,
   EVENT_UPDATE_MESSAGE_FLAGS,
+  LOGIN_SUCCESS,
 } from '../actionConstants';
 import {
   pmUnreadsKeyFromMessage,
@@ -93,6 +94,7 @@ export default (
   switch (action.type) {
     case LOGOUT:
     case ACCOUNT_SWITCH:
+    case LOGIN_SUCCESS:
       return initialState;
 
     case REGISTER_COMPLETE:

src/unread/unreadMentionsReducer.js

@@ -10,6 +10,7 @@ import {
   EVENT_NEW_MESSAGE,
   EVENT_MESSAGE_DELETE,
   EVENT_UPDATE_MESSAGE_FLAGS,
+  LOGIN_SUCCESS,
 } from '../actionConstants';
 import { addItemsToArray, removeItemsFromArray } from '../utils/immutability';
 import { NULL_ARRAY } from '../nullObjects';
@@ -51,6 +52,7 @@ export default (
   switch (action.type) {
     case LOGOUT:
     case ACCOUNT_SWITCH:
+    case LOGIN_SUCCESS:
       return initialState;
 
     case REGISTER_COMPLETE:

src/unread/unreadModel.js

@@ -23,6 +23,7 @@ import {
   EVENT_NEW_MESSAGE,
   EVENT_UPDATE_MESSAGE,
   EVENT_UPDATE_MESSAGE_FLAGS,
+  LOGIN_SUCCESS,
   LOGOUT,
   MESSAGE_FETCH_COMPLETE,
   REGISTER_COMPLETE,
@@ -226,7 +227,7 @@ function streamsReducer(
   switch (action.type) {
     case LOGOUT:
     case ACCOUNT_SWITCH:
-      // TODO(#4446) also LOGIN_SUCCESS, presumably
+    case LOGIN_SUCCESS:
       return initialStreamsState;
 
     case REGISTER_COMPLETE: {

src/unread/unreadPmsReducer.js

@@ -10,6 +10,7 @@ import {
   EVENT_NEW_MESSAGE,
   EVENT_MESSAGE_DELETE,
   EVENT_UPDATE_MESSAGE_FLAGS,
+  LOGIN_SUCCESS,
 } from '../actionConstants';
 import { addItemsToPmArray, removeItemsDeeply } from './unreadHelpers';
 import { NULL_ARRAY } from '../nullObjects';
@@ -93,6 +94,7 @@ export default (
   switch (action.type) {
     case LOGOUT:
     case ACCOUNT_SWITCH:
+    case LOGIN_SUCCESS:
       return initialState;
 
     case REGISTER_COMPLETE: