test(provider): distinguish OpenCode billing 401 from auth failure

Author: elkaix

packages/agent-core-v2/test/kosong/provider/opencode-billing-error.test.ts

@@ -0,0 +1,27 @@
+import { APIError as OpenAIAPIError } from 'openai';
+import { describe, expect, it } from 'vitest';
+
+import { PROVIDER_API_ERROR_CODE, PROVIDER_AUTH_ERROR_CODE } from '#/kosong/contract/errors';
+import { convertOpenAIError } from '#/kosong/provider/bases/openai/openai-common';
+
+describe('OpenCode billing rejection classification', () => {
+  it('keeps a 401 insufficient-balance response out of provider.auth_error', () => {
+    const source = new OpenAIAPIError(
+      401,
+      { message: 'Insufficient balance. Manage your billing here: https://opencode.ai/workspace/example/billing' },
+      '401 Insufficient balance. Manage your billing here: https://opencode.ai/workspace/example/billing',
+      new Headers({ 'x-request-id': 'req-123' }),
+    );
+
+    const error = convertOpenAIError(source);
+
+    expect(error.code).toBe(PROVIDER_API_ERROR_CODE);
+    expect(error.code).not.toBe(PROVIDER_AUTH_ERROR_CODE);
+    expect('statusCode' in error && error.statusCode).toBe(401);
+  });
+
+  it('still classifies a normal 401 as provider.auth_error', () => {
+    const source = new OpenAIAPIError(401, { message: 'Invalid API key' }, '401 Invalid API key', new Headers());
+    expect(convertOpenAIError(source).code).toBe(PROVIDER_AUTH_ERROR_CODE);
+  });
+});