[AI] Typescript: low hanging fruit (#7091)

* [AI] Use loot-core workspace in desktop-electron and fix related types

- Add loot-core as workspace dependency in desktop-electron
- Import GlobalPrefsJson from loot-core package in desktop-electron
- Allow null in usersSlice data type (UsersState)
- Add explicit SQL.Database return type to openDatabase in sqlite electron

Made-with: Cursor

* Re-add loot-core as a workspace dependency in desktop-electron

packages/desktop-client/src/users/usersSlice.ts

@@ -60,7 +60,7 @@ export const signOut = createAppAsyncThunk(
 );
 
 type UsersState = {
-  data: Awaited<ReturnType<Handlers['subscribe-get-user']>>;
+  data: Awaited<ReturnType<Handlers['subscribe-get-user']>> | null;
 };
 
 const initialState: UsersState = {

packages/desktop-electron/index.ts

@@ -25,7 +25,7 @@ import type {
 import { copy, exists, mkdir, remove } from 'fs-extra';
 import promiseRetry from 'promise-retry';
 
-import type { GlobalPrefsJson } from '../loot-core/src/types/prefs';
+import type { GlobalPrefsJson } from 'loot-core/src/types/prefs';
 
 import { getMenu } from './menu';
 import {

packages/desktop-electron/package.json

@@ -30,6 +30,7 @@
     "cross-env": "^10.1.0",
     "electron": "39.2.7",
     "electron-builder": "26.4.0",
+    "loot-core": "workspace:*",
     "typescript": "^5.9.3",
     "typescript-strict-plugin": "^2.4.4"
   },

packages/loot-core/src/platform/server/sqlite/index.electron.ts

@@ -100,7 +100,7 @@ function regexp(regex: string, text: string | null) {
   return new RegExp(regex).test(text || '') ? 1 : 0;
 }
 
-export function openDatabase(pathOrBuffer: string | Buffer) {
+export function openDatabase(pathOrBuffer: string | Buffer): SQL.Database {
   const db = new SQL(pathOrBuffer);
   // Define Unicode-aware LOWER, UPPER, and LIKE implementation.
   // This is necessary because better-sqlite3 uses SQLite build without ICU support.

upcoming-release-notes/7091.md

@@ -0,0 +1,6 @@
+---
+category: Maintenance
+authors: [MatissJanis]
+---
+
+TypeScript: clean up some types

yarn.lock

@@ -14415,6 +14415,7 @@ __metadata:
     electron: "npm:39.2.7"
     electron-builder: "npm:26.4.0"
     fs-extra: "npm:^11.3.3"
+    loot-core: "workspace:*"
     promise-retry: "npm:^2.0.1"
     typescript: "npm:^5.9.3"
     typescript-strict-plugin: "npm:^2.4.4"