detect setup auth ping failures

setup/lib/agent-ping.test.ts

@@ -0,0 +1,30 @@
+import { describe, expect, it } from 'vitest';
+
+import { classifyPingResult } from './agent-ping.js';
+
+describe('classifyPingResult', () => {
+  it('treats a normal text reply as ok', () => {
+    expect(classifyPingResult(0, 'pong\n')).toBe('ok');
+  });
+
+  it('detects Anthropic auth errors printed as a chat reply', () => {
+    expect(
+      classifyPingResult(
+        0,
+        'Failed to authenticate. API Error: 401 {"type":"error","error":{"type":"authentication_error","message":"Invalid bearer token"}}',
+      ),
+    ).toBe('auth_error');
+  });
+
+  it('detects auth errors on stderr too', () => {
+    expect(classifyPingResult(1, '', 'Authentication error')).toBe('auth_error');
+  });
+
+  it('preserves socket errors', () => {
+    expect(classifyPingResult(2, '')).toBe('socket_error');
+  });
+
+  it('treats empty output as no reply', () => {
+    expect(classifyPingResult(0, '')).toBe('no_reply');
+  });
+});