feat(providers): allow GitHub Copilot endpoint overrides for enterprise/GHE (#4220)

tests/providers/test_github_copilot_enterprise.py

@@ -0,0 +1,32 @@
+"""Regression tests for GitHub Enterprise / Copilot for Business endpoint overrides (#4220)."""
+
+from __future__ import annotations
+
+from nanobot.providers import github_copilot_provider as gc
+
+
+def test_resolve_falls_back_to_default_without_env(monkeypatch):
+    monkeypatch.delenv("NANOBOT_COPILOT_BASE_URL", raising=False)
+    assert gc._resolve("NANOBOT_COPILOT_BASE_URL", gc.DEFAULT_COPILOT_BASE_URL) == (
+        gc.DEFAULT_COPILOT_BASE_URL
+    )
+
+
+def test_resolve_uses_env_override_and_strips(monkeypatch):
+    monkeypatch.setenv("NANOBOT_COPILOT_TOKEN_URL", "  https://api.acme.ghe.com/copilot_internal/v2/token  ")
+    assert gc._resolve("NANOBOT_COPILOT_TOKEN_URL", gc.DEFAULT_COPILOT_TOKEN_URL) == (
+        "https://api.acme.ghe.com/copilot_internal/v2/token"
+    )
+
+
+def test_blank_env_override_falls_back_to_default(monkeypatch):
+    monkeypatch.setenv("NANOBOT_COPILOT_BASE_URL", "   ")
+    assert gc._resolve("NANOBOT_COPILOT_BASE_URL", gc.DEFAULT_COPILOT_BASE_URL) == (
+        gc.DEFAULT_COPILOT_BASE_URL
+    )
+
+
+def test_provider_api_base_honors_env_override(monkeypatch):
+    monkeypatch.setenv("NANOBOT_COPILOT_BASE_URL", "https://copilot-api.acme.ghe.com")
+    provider = gc.GitHubCopilotProvider()
+    assert provider.api_base == "https://copilot-api.acme.ghe.com"