From 427deb4a70ad03e82bf360d3ea1529a43aea7e6c Mon Sep 17 00:00:00 2001
From: Xubin Ren <xubinrencs@gmail.com>
Date: Wed, 22 Apr 2026 06:53:37 +0000
Subject: [PATCH] test(providers): add regression tests for GitHub Copilot
 /responses routing

Locks in the four behaviors introduced by the fix so they can't silently
revert:
- _should_use_responses_api accepts github_copilot on its non-OpenAI base
- _build_responses_body strips the 'github_copilot/' routing prefix
- /responses failures on github_copilot do not fall back to /chat/completions

Made-with: Cursor
---
 .../providers/test_github_copilot_routing.py  | 79 +++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 tests/providers/test_github_copilot_routing.py

diff --git a/tests/providers/test_github_copilot_routing.py b/tests/providers/test_github_copilot_routing.py
new file mode 100644
index 00000000..90e4cb4d
--- /dev/null
+++ b/tests/providers/test_github_copilot_routing.py
@@ -0,0 +1,79 @@
+"""Regression tests for GitHub Copilot /responses routing.
+
+Covers the Copilot-specific branches added to route GPT-5 / o-series models
+through the /responses endpoint without falling back to /chat/completions.
+"""
+
+from __future__ import annotations
+
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from nanobot.providers.openai_compat_provider import OpenAICompatProvider
+from nanobot.providers.registry import find_by_name
+
+
+def _make_copilot_provider() -> OpenAICompatProvider:
+    """Build a bare provider with the real github_copilot spec (no network)."""
+    p = OpenAICompatProvider.__new__(OpenAICompatProvider)
+    p.default_model = "github_copilot/gpt-5.4-mini"
+    p._spec = find_by_name("github_copilot")
+    p._effective_base = "https://api.githubcopilot.com"
+    p._responses_failures = {}
+    p._responses_tripped_at = {}
+    return p
+
+
+def test_should_use_responses_api_allows_github_copilot_non_openai_base():
+    """github_copilot bypasses the direct-OpenAI base check and still opts in for GPT-5."""
+    provider = _make_copilot_provider()
+    assert provider._should_use_responses_api("github_copilot/gpt-5.4-mini", None) is True
+    assert provider._should_use_responses_api("github_copilot/o3", None) is True
+
+
+def test_build_responses_body_strips_github_copilot_prefix():
+    """/responses body must send the bare model name; gateway rejects routing prefixes."""
+    provider = _make_copilot_provider()
+    body = provider._build_responses_body(
+        messages=[{"role": "user", "content": "hi"}],
+        tools=None,
+        model="github_copilot/gpt-5.4-mini",
+        max_tokens=16,
+        temperature=0.1,
+        reasoning_effort=None,
+        tool_choice=None,
+    )
+    assert body["model"] == "gpt-5.4-mini"
+
+
+@pytest.mark.asyncio
+async def test_github_copilot_does_not_fall_back_from_responses_error():
+    """On /responses failure, github_copilot must re-raise instead of hitting /chat/completions."""
+    from nanobot.providers.github_copilot_provider import GitHubCopilotProvider
+
+    mock_client = MagicMock()
+    mock_client.api_key = "no-key"
+
+    class _CompatError(Exception):
+        """Looks like a fallback-eligible error on other providers."""
+        status_code = 400
+        body = "Unsupported parameter responses api"
+
+    mock_client.responses.create = AsyncMock(side_effect=_CompatError("boom"))
+    mock_client.chat.completions.create = AsyncMock()
+
+    with patch("nanobot.providers.openai_compat_provider.AsyncOpenAI", return_value=mock_client):
+        provider = GitHubCopilotProvider(default_model="github_copilot/gpt-5.4-mini")
+    provider._get_copilot_access_token = AsyncMock(return_value="copilot-access-token")
+
+    response = await provider.chat(
+        messages=[{"role": "user", "content": "hi"}],
+        model="github_copilot/gpt-5.4-mini",
+        max_tokens=16,
+        temperature=0.1,
+    )
+
+    assert response.finish_reason == "error"
+    mock_client.responses.create.assert_awaited_once()
+    mock_client.chat.completions.create.assert_not_awaited()