Include @mentioned names in search results

ts/util/fuse.ts

@@ -0,0 +1,53 @@
+// Copyright 2023 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import Fuse from 'fuse.js';
+
+import { removeDiacritics } from './removeDiacritics';
+
+const cachedIndices: Map<
+  Fuse.IFuseOptions<unknown>,
+  WeakMap<ReadonlyArray<unknown>, Fuse<unknown>>
+> = new Map();
+
+export function getCachedFuseIndex<T>(
+  list: ReadonlyArray<T>,
+  options: Fuse.IFuseOptions<T>
+): Fuse<T> {
+  // Helper to retrieve a cached fuse index or create one if needed. Indices are uniquely
+  // identified by their `options` and the `list` of values being indexed. Both should
+  // remain referentially static in order to avoid unnecessarily re-indexing
+  let indicesForOptions = cachedIndices.get(
+    options as Fuse.IFuseOptions<unknown>
+  );
+
+  if (!indicesForOptions) {
+    indicesForOptions = new WeakMap();
+    cachedIndices.set(options as Fuse.IFuseOptions<unknown>, indicesForOptions);
+  }
+
+  let index = indicesForOptions.get(list);
+  if (!index) {
+    index = new Fuse<T>(list, options);
+    indicesForOptions.set(list, index);
+  }
+
+  // Map's types don't allow us to specify that the type of the value depends on the
+  // type of the key, so we have to cast it here.
+  return index as unknown as Fuse<T>;
+}
+
+export const fuseGetFnRemoveDiacritics: Fuse.FuseGetFunction<unknown> = (
+  ...args
+) => {
+  const text = Fuse.config.getFn(...args);
+  if (!text) {
+    return text;
+  }
+
+  if (typeof text === 'string') {
+    return removeDiacritics(text);
+  }
+
+  return text.map(removeDiacritics);
+};