Normalize diacritics when searching conversations

ts/state/ducks/search.ts

@@ -36,6 +36,7 @@ import {
   CONVERSATION_UNLOADED,
   TARGETED_CONVERSATION_CHANGED,
 } from './conversations';
+import { removeDiacritics } from '../../util/removeDiacritics';
 
 const {
   searchMessages: dataSearchMessages,
@@ -286,8 +287,14 @@ async function queryConversationsAndContacts(
   const { ourConversationId, noteToSelf, regionCode, allConversations } =
     options;
 
+  const normalizedQuery = removeDiacritics(query);
+
   const searchResults: Array<ConversationType> =
-    filterAndSortConversationsByRecent(allConversations, query, regionCode);
+    filterAndSortConversationsByRecent(
+      allConversations,
+      normalizedQuery,
+      regionCode
+    );
 
   // Split into two groups - active conversations and items just from address book
   let conversationIds: Array<string> = [];

ts/util/filterAndSortConversations.ts

@@ -6,6 +6,7 @@ import Fuse from 'fuse.js';
 import type { ConversationType } from '../state/ducks/conversations';
 import { parseAndFormatPhoneNumber } from './libphonenumberInstance';
 import { WEEK } from './durations';
+import { removeDiacritics } from './removeDiacritics';
 
 // Fuse.js scores have order of 0.01
 const ACTIVE_AT_SCORE_FACTOR = (1 / WEEK) * 0.01;
@@ -44,6 +45,18 @@ const FUSE_OPTIONS: Fuse.IFuseOptions<ConversationType> = {
       weight: 0.5,
     },
   ],
+  getFn: (...args) => {
+    const text = Fuse.config.getFn(...args);
+    if (!text) {
+      return text;
+    }
+
+    if (typeof text === 'string') {
+      return removeDiacritics(text);
+    }
+
+    return text.map(removeDiacritics);
+  },
 };
 
 const cachedIndices = new WeakMap<

ts/util/removeDiacritics.ts

@@ -0,0 +1,6 @@
+// Copyright 2023 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+export function removeDiacritics(text: string): string {
+  return text.normalize('NFD').replace(/\p{Diacritic}/gu, '');
+}