api types: Shorten name of "cooked" response to ServerSettings

The type for the raw, unprocessed payload from the server is now
just named ApiResponseServerSettings, from
ServerApiResponseServerSettings.

The type for the "cooked" payload, with our validation on
`realm_name`, now has the shorter name ServerSettings, from
ApiResponseServerSettings.

The validation is done in a new helper function, `transform`. We'll
add more stuff there soon, and change the ServerSettings type to be
a more "cooked" form of the data.

Author: chrisbobbe

src/account/AccountPickScreen.js

@@ -17,7 +17,7 @@ import Screen from '../common/Screen';
 import ViewPlaceholder from '../common/ViewPlaceholder';
 import AccountList from './AccountList';
 import { accountSwitch, removeAccount } from '../actions';
-import type { ApiResponseServerSettings } from '../api/settings/getServerSettings';
+import type { ServerSettings } from '../api/settings/getServerSettings';
 import { showConfirmationDialog, showErrorAlert } from '../utils/info';
 import { tryStopNotifications } from '../notification/notifTokens';
 
@@ -46,7 +46,7 @@ export default function AccountPickScreen(props: Props): Node {
         });
       } else {
         try {
-          const serverSettings: ApiResponseServerSettings = await api.getServerSettings(realm);
+          const serverSettings: ServerSettings = await api.getServerSettings(realm);
           navigation.push('auth', { serverSettings });
         } catch {
           // TODO: show specific error message from error object

src/api/settings/getServerSettings.js

@@ -25,7 +25,7 @@ export type ExternalAuthenticationMethod = {|
 
 /** https://zulip.com/api/get-server-settings */
 // Current to FL 121.
-export type ApiResponseServerSettings = {|
+type ApiResponseServerSettings = {|
   ...$Exact<ApiResponseSuccess>,
   authentication_methods: AuthenticationMethods,
 
@@ -45,16 +45,6 @@ export type ApiResponseServerSettings = {|
   email_auth_enabled: boolean,
   require_email_format_usernames: boolean,
   realm_uri: string,
-  realm_name: string,
-  realm_icon: string,
-  realm_description: string,
-
-  // TODO(server-5.0): New in FL 116.
-  realm_web_public_access_enabled?: boolean,
-|};
-
-type ServerApiResponseServerSettings = {|
-  ...ApiResponseServerSettings,
 
   // When missing, the user requested the root domain of a Zulip server, but
   // there is no realm there. User error.
@@ -71,18 +61,26 @@ type ServerApiResponseServerSettings = {|
   // TODO(server-future): Then, when all supported servers give that error,
   //   make this property required.
   realm_name?: string,
+
+  realm_icon: string,
+  realm_description: string,
+
+  // TODO(server-5.0): New in FL 116.
+  realm_web_public_access_enabled?: boolean,
 |};
 
-/** See https://zulip.com/api/get-server-settings */
-export default async (realm: URL): Promise<ApiResponseServerSettings> => {
-  const result: ServerApiResponseServerSettings = await apiGet(
-    { apiKey: '', email: '', realm },
-    'server_settings',
-  );
+export type ServerSettings = $ReadOnly<{|
+  ...ApiResponseServerSettings,
+  +realm_name: string,
+|}>;
 
-  const { realm_name } = result;
+/**
+ * Make a ServerSettings from a raw API response.
+ */
+function transform(raw: ApiResponseServerSettings): ServerSettings {
+  const { realm_name } = raw;
   if (realm_name == null) {
-    // See comment on realm_name in ServerApiResponseServerSettings.
+    // See comment on realm_name in ApiResponseServerSettings.
     //
     // This error copies the proper error that servers *sometimes* give when
     // the root domain is requested and there's no realm there. [1]
@@ -95,5 +93,18 @@ export default async (realm: URL): Promise<ApiResponseServerSettings> => {
     throw new ApiError(400, { code: 'BAD_REQUEST', msg: 'Subdomain required', result: 'error' });
   }
 
-  return { ...result, realm_name };
+  return {
+    ...raw,
+    realm_name,
+  };
+}
+
+/** See https://zulip.com/api/get-server-settings */
+export default async (realm: URL): Promise<ServerSettings> => {
+  const result: ApiResponseServerSettings = await apiGet(
+    { apiKey: '', email: '', realm },
+    'server_settings',
+  );
+
+  return transform(result);
 };

src/start/AuthScreen.js

@@ -7,7 +7,7 @@ import type { AppleAuthenticationCredential } from 'expo-apple-authentication';
 import * as AppleAuthentication from 'expo-apple-authentication';
 
 import type {
-  ApiResponseServerSettings,
+  ServerSettings,
   AuthenticationMethods,
   ExternalAuthenticationMethod,
 } from '../api/settings/getServerSettings';
@@ -173,7 +173,7 @@ export const activeAuthentications = (
 type OuterProps = $ReadOnly<{|
   // These should be passed from React Navigation
   navigation: AppNavigationProp<'auth'>,
-  route: RouteProp<'auth', {| serverSettings: ApiResponseServerSettings |}>,
+  route: RouteProp<'auth', {| serverSettings: ServerSettings |}>,
 |}>;
 
 type SelectorProps = $ReadOnly<{|

src/start/RealmInputScreen.js

@@ -6,7 +6,7 @@ import { useFocusEffect } from '@react-navigation/native';
 
 import type { RouteProp } from '../react-navigation';
 import type { AppNavigationProp } from '../nav/AppNavigator';
-import type { ApiResponseServerSettings } from '../api/settings/getServerSettings';
+import type { ServerSettings } from '../api/settings/getServerSettings';
 import ErrorMsg from '../common/ErrorMsg';
 import ZulipTextIntl from '../common/ZulipTextIntl';
 import Screen from '../common/Screen';
@@ -72,7 +72,7 @@ export default function RealmInputScreen(props: Props): Node {
     setProgress(true);
     setError(null);
     try {
-      const serverSettings: ApiResponseServerSettings = await api.getServerSettings(parsedRealm);
+      const serverSettings: ServerSettings = await api.getServerSettings(parsedRealm);
       navigation.push('auth', { serverSettings });
       Keyboard.dismiss();
     } catch (errorIllTyped) {