[web] move checking for desktop Safari to constant

Summary:
I misunderstood @tomek's suggestion from here: https://phab.comm.dev/D8124?id=27491#inline-52847

Moving not only function result to const but entire logic as this will not change during app lifetime (this is not true for tests but this is handled separately)

Test Plan:
1. Check if this const is truthy for Safari
2. Check if this const is falsy for other browser (like chrome)

Reviewers: tomek

Reviewed By: tomek

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D8226

web/database/database-module-provider.js

@@ -22,8 +22,6 @@ const databaseStatuses = Object.freeze({
 
 type DatabaseStatus = $Values<typeof databaseStatuses>;
 
-const isSafari = isDesktopSafari();
-
 class DatabaseModule {
   worker: SharedWorker;
   workerProxy: WorkerConnectionProxy;
@@ -36,7 +34,7 @@ class DatabaseModule {
       : preloadedState.currentUserInfo?.id;
     const isSupported = isSQLiteSupported(currentLoggedInUserID);
 
-    if (!isSupported || isSafari) {
+    if (!isSupported || isDesktopSafari) {
       this.status = databaseStatuses.notSupported;
     } else {
       this.init();

web/database/sqlite-data-handler.js

@@ -17,8 +17,6 @@ import {
 import { useSelector } from '../redux/redux-utils.js';
 import { workerRequestMessageTypes } from '../types/worker-types.js';
 
-const isSafari = isDesktopSafari();
-
 async function getSafariEncryptionKey(): Promise<SubtleCrypto$JsonWebKey> {
   const encryptionKey = await localforage.getItem(SQLITE_ENCRYPTION_KEY);
   if (encryptionKey) {
@@ -69,7 +67,7 @@ function SQLiteDataHandler(): React.Node {
     (async () => {
       if (currentLoggedInUserID) {
         let databaseEncryptionKeyJWK = null;
-        if (isSafari) {
+        if (isDesktopSafari) {
           databaseEncryptionKeyJWK = await getSafariEncryptionKey();
         }
         await databaseModule.initDBForLoggedInUser(

web/database/utils/db-utils.js

@@ -8,6 +8,8 @@ import { isDev } from 'lib/utils/dev-utils.js';
 
 import { DB_SUPPORTED_BROWSERS, DB_SUPPORTED_OS } from './constants.js';
 
+const browser = detectBrowser();
+
 function parseSQLiteQueryResult<T>(result: QueryExecResult): T[] {
   const { columns, values } = result;
   return values.map(rowResult => {
@@ -38,16 +40,13 @@ function isSQLiteSupported(currentLoggedInUserID: ?string): boolean {
     return false;
   }
 
-  const browser = detectBrowser();
   return (
     DB_SUPPORTED_OS.includes(browser.os) &&
     DB_SUPPORTED_BROWSERS.includes(browser.name)
   );
 }
 
-function isDesktopSafari(): boolean {
-  const browser = detectBrowser();
-  return browser.name === 'safari' && browser.os === 'Mac OS';
-}
+const isDesktopSafari: boolean =
+  browser && browser.name === 'safari' && browser.os === 'Mac OS';
 
 export { parseMultiStatementSQLiteResult, isSQLiteSupported, isDesktopSafari };