api: Intentionally handle removal of realm_email_address_visibility

I can't find a message in `#api design` on CZO that's explicitly
about removing realm_email_address_visibility from the register
response. The `#api design` discussion about transitioning that from
an org- to a user-level setting is here:
  https://chat.zulip.org/#narrow/stream/378-api-design/topic/email.20address.20visibility/near/1296131
That discussion includes mentions of the user-object fields that are
about email addresses, and it includes mentions of the per-user
visibility setting, but I don't see anything about removing the
realm setting from the /register response.

In retrospect, its removal there would have been an obvious thing to
anticipate and handle in our types. Oh well, better late than never.

Luckily I don't think there was a user-facing bug here. At FL 163+,
the value that we've been typing as the enum EmailAddressVisibility
will actually be `undefined`, but that's OK because on 163+ we don't
end up doing anything with it.

src/__tests__/lib/exampleData.js

@@ -21,7 +21,7 @@ import { randString, randInt } from '../../utils/misc';
 import { makeUserId } from '../../api/idTypes';
 import type { InitialData } from '../../api/apiTypes';
 import { EventTypes, type UpdateMessageEvent } from '../../api/eventTypes';
-import { CreateWebPublicStreamPolicy, EmailAddressVisibility } from '../../api/permissionsTypes';
+import { CreateWebPublicStreamPolicy } from '../../api/permissionsTypes';
 import type {
   AccountSwitchAction,
   LoginSuccessAction,
@@ -784,7 +784,6 @@ export const action = Object.freeze({
       realm_digest_weekday: 2,
       realm_disallow_disposable_email_addresses: true,
       realm_edit_topic_policy: 3,
-      realm_email_address_visibility: EmailAddressVisibility.Admins,
       realm_email_auth_enabled: true,
       realm_email_changes_disabled: true,
       realm_emails_restricted_to_domains: false,

src/api/initialDataTypes.js

@@ -231,7 +231,9 @@ export type InitialDataRealm = $ReadOnly<{|
   // TODO(server-5.0): Added in feat. 75, replacing realm_allow_community_topic_editing
   realm_edit_topic_policy?: number,
 
-  realm_email_address_visibility: EmailAddressVisibility,
+  // TODO(server-7.0): Removed in feat. 163
+  realm_email_address_visibility?: EmailAddressVisibility,
+
   realm_email_auth_enabled: boolean,
   realm_email_changes_disabled: boolean,
   realm_emails_restricted_to_domains: boolean,

src/api/realmDataTypes.js

@@ -59,7 +59,7 @@ export type RealmDataForUpdate = $ReadOnly<{
     InitialDataRealm['realm_disallow_disposable_email_addresses'],
   edit_topic_policy:
     InitialDataRealm['realm_edit_topic_policy'],
-  email_address_visibility:
+  email_address_visibility: // removed in feat. 163
     InitialDataRealm['realm_email_address_visibility'],
   email_changes_disabled:
     InitialDataRealm['realm_email_changes_disabled'],

src/realm/__tests__/realmReducer-test.js

@@ -68,7 +68,7 @@ describe('realmReducer', () => {
         waitingPeriodThreshold: action.data.realm_waiting_period_threshold,
         allowEditHistory: action.data.realm_allow_edit_history,
         enableReadReceipts: action.data.realm_enable_read_receipts,
-        emailAddressVisibility: action.data.realm_email_address_visibility,
+        emailAddressVisibility: null,
 
         //
         // InitialDataRealmUser

src/realm/realmReducer.js

@@ -8,7 +8,6 @@ import type {
 import {
   CreatePublicOrPrivateStreamPolicy,
   CreateWebPublicStreamPolicy,
-  EmailAddressVisibility,
 } from '../api/permissionsTypes';
 import { EventTypes } from '../api/eventTypes';
 import {
@@ -53,7 +52,7 @@ const initialState = {
   waitingPeriodThreshold: 90,
   allowEditHistory: false,
   enableReadReceipts: false,
-  emailAddressVisibility: EmailAddressVisibility.Admins,
+  emailAddressVisibility: null,
 
   //
   // InitialDataRealmUser
@@ -165,7 +164,7 @@ export default (
         waitingPeriodThreshold: action.data.realm_waiting_period_threshold,
         allowEditHistory: action.data.realm_allow_edit_history,
         enableReadReceipts: action.data.realm_enable_read_receipts ?? false,
-        emailAddressVisibility: action.data.realm_email_address_visibility,
+        emailAddressVisibility: action.data.realm_email_address_visibility ?? null,
 
         //
         // InitialDataRealmUser

src/reduxTypes.js

@@ -310,7 +310,7 @@ export type RealmState = {|
   +waitingPeriodThreshold: number,
   +allowEditHistory: boolean,
   +enableReadReceipts: boolean,
-  +emailAddressVisibility: EmailAddressVisibility,
+  +emailAddressVisibility: EmailAddressVisibility | null,
 
   //
   // InitialDataRealmUser

src/storage/__tests__/migrations-test.js

@@ -105,7 +105,7 @@ describe('migrations', () => {
   // What `base` becomes after all migrations.
   const endBase = {
     ...base52,
-    migrations: { version: 60 },
+    migrations: { version: 61 },
   };
 
   for (const [desc, before, after] of [
@@ -128,9 +128,9 @@ describe('migrations', () => {
     // redundant with this one, because none of the migration steps notice
     // whether any properties outside `storeKeys` are present or not.
     [
-      'check dropCache at 60',
+      'check dropCache at 61',
       // Just before the `dropCache`, plus a `cacheKeys` property, plus junk.
-      { ...base52, migrations: { version: 59 }, mute: [], nonsense: [1, 2, 3] },
+      { ...base52, migrations: { version: 60 }, mute: [], nonsense: [1, 2, 3] },
       // Should wind up with the same result as without the extra properties.
       endBase,
     ],

src/storage/migrations.js

@@ -517,6 +517,9 @@ const migrationsInner: {| [string]: (LessPartialState) => LessPartialState |} =
   // Discard invalid enum values from `state.mute`.
   '60': dropCache,
 
+  // Fix emailAddressVisibility accidentally being undefined/dropped
+  '61': dropCache,
+
   // TIP: When adding a migration, consider just using `dropCache`.
   //   (See its jsdoc for guidance on when that's the right answer.)
 };

src/users/userSelectors.js

@@ -323,9 +323,7 @@ export function getDisplayEmailForUser(realm: RealmState, user: UserOrBot): stri
   if (user.delivery_email !== undefined) {
     return user.delivery_email;
   } else if (realm.emailAddressVisibility === EmailAddressVisibility.Everyone) {
-    // On future servers, we expect this case will never happen: we'll always include
-    // a delivery_email when you have access, including when the visibility is Everyone
-    // https://github.com/zulip/zulip-mobile/pull/5515#discussion_r997731727
+    // TODO(server-7.0): Not reached on FL 163+, where delivery_email is always present.
     return user.email;
   } else {
     return null;