Convert IndexedDB code to TypeScript

ts/background.ts

@@ -24,6 +24,7 @@ import type {
 } from './model-types.d';
 import * as Bytes from './Bytes';
 import * as Timers from './Timers';
+import * as indexedDb from './indexeddb';
 import type { WhatIsThis } from './window.d';
 import type { Receipt } from './types/Receipt';
 import { getTitleBarVisibility, TitleBarVisibility } from './types/Settings';
@@ -494,8 +495,6 @@ export async function startApp(): Promise<void> {
   //   of preload.js processing
   window.setImmediate = window.nodeSetImmediate;
 
-  const { removeDatabase: removeIndexedDB, doesDatabaseExist } =
-    window.Signal.IndexedDB;
   const { Message } = window.Signal.Types;
   const {
     upgradeMessageSchema,
@@ -551,7 +550,7 @@ export async function startApp(): Promise<void> {
 
   const version = await window.Signal.Data.getItemById('version');
   if (!version) {
-    const isIndexedDBPresent = await doesDatabaseExist();
+    const isIndexedDBPresent = await indexedDb.doesDatabaseExist();
     if (isIndexedDBPresent) {
       log.info('Found IndexedDB database.');
       try {
@@ -582,7 +581,7 @@ export async function startApp(): Promise<void> {
         log.info('Deleting IndexedDB file...');
 
         await Promise.all([
-          removeIndexedDB(),
+          indexedDb.removeDatabase(),
           window.Signal.Data.removeAll(),
           window.Signal.Data.removeIndexedDBFiles(),
         ]);

ts/indexeddb.ts

@@ -0,0 +1,52 @@
+// Copyright 2018-2022 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+const LEGACY_DATABASE_ID = 'signal';
+
+export async function doesDatabaseExist(): Promise<boolean> {
+  window.SignalContext.log.info(
+    'Checking for the existence of IndexedDB data...'
+  );
+  return new Promise((resolve, reject) => {
+    const req = window.indexedDB.open(LEGACY_DATABASE_ID);
+
+    let existed = true;
+
+    let timer: undefined | ReturnType<typeof setTimeout> = setTimeout(() => {
+      window.SignalContext.log.warn(
+        'doesDatabaseExist: Timed out attempting to check IndexedDB status'
+      );
+      return resolve(false);
+    }, 1000);
+
+    const clearTimer = () => {
+      if (timer !== undefined) {
+        clearTimeout(timer);
+        timer = undefined;
+      }
+    };
+
+    req.onerror = error => {
+      clearTimer();
+      reject(error);
+    };
+    req.onsuccess = () => {
+      clearTimer();
+      req.result.close();
+      resolve(existed);
+    };
+    req.onupgradeneeded = () => {
+      if (req.result.version === 1) {
+        existed = false;
+        window.indexedDB.deleteDatabase(LEGACY_DATABASE_ID);
+      }
+    };
+  });
+}
+
+export function removeDatabase(): void {
+  window.SignalContext.log.info(
+    `Deleting IndexedDB database '${LEGACY_DATABASE_ID}'`
+  );
+  window.indexedDB.deleteDatabase(LEGACY_DATABASE_ID);
+}

ts/window.d.ts

@@ -398,10 +398,6 @@ declare global {
         WhatsNewLink: typeof WhatsNewLink;
       };
       OS: typeof OS;
-      IndexedDB: {
-        removeDatabase: WhatIsThis;
-        doesDatabaseExist: WhatIsThis;
-      };
       Views: WhatIsThis;
       State: {
         createStore: typeof createStore;