getInitials: handle more cases

See [#5029]][0].

[0]: https://github.com/signalapp/Signal-Desktop/pull/5029

ts/test-both/util/getInitials_test.ts

@@ -0,0 +1,62 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+
+import { getInitials } from '../../util/getInitials';
+
+describe('getInitials', () => {
+  it('returns undefined when passed undefined', () => {
+    assert.isUndefined(getInitials(undefined));
+  });
+
+  it('returns undefined when passed an empty string', () => {
+    assert.isUndefined(getInitials(''));
+  });
+
+  it('returns undefined when passed a string with no letters', () => {
+    assert.isUndefined(getInitials('123 !@#$%'));
+  });
+
+  it('returns the first letter of a name that is one ASCII word', () => {
+    assert.strictEqual(getInitials('Foo'), 'F');
+    assert.strictEqual(getInitials('Bo'), 'B');
+  });
+
+  [
+    'Foo Bar',
+    'foo bar',
+    'F Bar',
+    'Foo B',
+    'FB',
+    'F.B.',
+    '0Foo 1Bar',
+    "Foo B'Ar",
+    'Foo Q Bar',
+    'Foo Q. Bar',
+    'Foo Qux Bar',
+    'Foo "Qux" Bar',
+    'Foo-Qux Bar',
+    'Foo Bar-Qux',
+    "Foo b'Arr",
+  ].forEach(name => {
+    it(`returns 'FB' for '${name}'`, () => {
+      assert.strictEqual(getInitials(name), 'FB');
+    });
+  });
+
+  it('returns initials for languages with non-Latin alphabets', () => {
+    assert.strictEqual(getInitials('Иван Иванов'), 'ИИ');
+    assert.strictEqual(getInitials('山田 太郎'), '山太');
+    assert.strictEqual(getInitials('王五'), '王五');
+  });
+
+  it('returns initials for right-to-left languages', () => {
+    assert.strictEqual(getInitials('فلانة الفلانية'), 'فا');
+    assert.strictEqual(getInitials('ישראלה ישראלי'), 'יי');
+  });
+
+  it('returns initials with diacritical marks', () => {
+    assert.strictEqual(getInitials('Ḟoo Ḅar'), 'ḞḄ');
+  });
+});

ts/util/getInitials.ts

@@ -1,24 +1,31 @@
 // Copyright 2018-2020 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
-const BAD_CHARACTERS = /[^A-Za-z\s]+/g;
-const WHITESPACE = /\s+/g;
-
-function removeNonInitials(name: string) {
-  return name.replace(BAD_CHARACTERS, '').replace(WHITESPACE, ' ');
-}
-
 export function getInitials(name?: string): string | undefined {
   if (!name) {
     return undefined;
   }
 
-  const cleaned = removeNonInitials(name);
-  const parts = cleaned.split(' ');
-  const initials = parts.map(part => part.trim()[0]);
-  if (!initials.length) {
+  const parsedName = name
+    // remove all chars that are not letters or separators
+    .replace(/[^\p{L}\p{Z}]+/gu, '')
+    // replace all chars that are separators with a single ASCII space
+    .replace(/\p{Z}+/gu, ' ')
+    .trim();
+
+  if (!parsedName) {
     return undefined;
   }
 
-  return initials.slice(0, 2).join('');
+  // check if chars in the parsed string are initials
+  if (parsedName.length === 2 && parsedName === parsedName.toUpperCase()) {
+    return parsedName;
+  }
+
+  const parts = parsedName.toUpperCase().split(' ');
+  const partsLen = parts.length;
+
+  return partsLen === 1
+    ? parts[0].charAt(0)
+    : parts[0].charAt(0) + parts[partsLen - 1].charAt(0);
 }