test: подключить vitest и покрыть утилиты юнит-тестами

src/utils/sanitizeSurrogates.test.ts

@@ -0,0 +1,28 @@
+import { describe, expect, it } from 'vitest';
+import { sanitizeSurrogates } from './sanitizeSurrogates';
+
+describe('sanitizeSurrogates', () => {
+  it('returns surrogate-free strings unchanged', () => {
+    expect(sanitizeSurrogates('')).toBe('');
+    expect(sanitizeSurrogates('https://host/sub/uuid#remark')).toBe('https://host/sub/uuid#remark');
+  });
+
+  it('keeps valid surrogate pairs intact', () => {
+    expect(sanitizeSurrogates('server 😀 name')).toBe('server 😀 name');
+  });
+
+  it('replaces a lone high surrogate', () => {
+    expect(sanitizeSurrogates('abc\uD83D')).toBe('abc<62>');
+    expect(sanitizeSurrogates('\uD83Dxyz')).toBe('<27>xyz');
+  });
+
+  it('replaces a lone low surrogate', () => {
+    expect(sanitizeSurrogates('abc\uDE00def')).toBe('abc<62>def');
+  });
+
+  it('makes a truncated-emoji string safe for encodeURI', () => {
+    const broken = 'remark \uD83D truncated';
+    expect(() => encodeURI(broken)).toThrow();
+    expect(() => encodeURI(sanitizeSurrogates(broken))).not.toThrow();
+  });
+});