chore: establish learning module baseline

OpenMAIC/tests/audio/tts-rate-limit.test.ts

@@ -0,0 +1,22 @@
+import { describe, it, expect } from 'vitest';
+import { throwIfTtsRateLimited, TTSRateLimitError } from '@/lib/audio/tts-providers';
+
+describe('throwIfTtsRateLimited', () => {
+  it('throws a typed TTSRateLimitError on HTTP 429', () => {
+    expect(() => throwIfTtsRateLimited('OpenAI', 429)).toThrow(TTSRateLimitError);
+    try {
+      throwIfTtsRateLimited('OpenAI', 429);
+      throw new Error('should have thrown');
+    } catch (e) {
+      expect(e).toBeInstanceOf(TTSRateLimitError);
+      expect((e as TTSRateLimitError).provider).toBe('OpenAI');
+    }
+  });
+
+  it('does not throw on non-429 statuses', () => {
+    expect(() => throwIfTtsRateLimited('OpenAI', 200)).not.toThrow();
+    expect(() => throwIfTtsRateLimited('OpenAI', 401)).not.toThrow();
+    expect(() => throwIfTtsRateLimited('OpenAI', 500)).not.toThrow();
+    expect(() => throwIfTtsRateLimited('OpenAI', 503)).not.toThrow();
+  });
+});