test: split provider classification tests (#4392)

tests/test_provider_classification_errors.py

@@ -0,0 +1,71 @@
+"""Upstream-error formatting for provider setup (REAL src.llm_core).
+
+Split from `test_provider_classification.py` to keep error-message formatting
+separate from provider identification.
+
+  * `_format_upstream_error` — turns a raw upstream HTTP status + body into the
+    one-line, provider-aware message the UI shows ("Provider probes" degraded
+    reporting in the roadmap).
+
+conftest.py stubs the heavy deps (sqlalchemy, src.database), so importing the
+real module is side-effect free.
+"""
+from src.llm_core import _format_upstream_error
+
+
+# ── _format_upstream_error ──
+# Status + body → one-line provider-aware sentence.
+
+class TestFormatUpstreamError:
+    def test_401_rejects_key_with_provider_and_detail(self):
+        msg = _format_upstream_error(
+            401, '{"error": {"message": "Invalid API key"}}', "https://api.x.ai/v1"
+        )
+        assert msg.startswith("xAI rejected the API key")
+        assert "Invalid API key" in msg
+        assert "re-paste the key" in msg
+
+    def test_403_denies_access(self):
+        msg = _format_upstream_error(
+            403, '{"error": {"message": "Forbidden"}}', "https://api.openai.com/v1"
+        )
+        assert "OpenAI denied access (403)" in msg
+        assert "Forbidden" in msg
+
+    def test_404_points_at_base_url(self):
+        msg = _format_upstream_error(404, "", "https://api.groq.com/openai/v1")
+        assert msg == "Groq returned 404 — check the base URL and model name."
+
+    def test_429_rate_limited(self):
+        msg = _format_upstream_error(
+            429, '{"error": {"message": "slow down"}}', "https://api.anthropic.com"
+        )
+        assert msg.startswith("Anthropic rate-limited the request (429).")
+        assert "slow down" in msg
+
+    def test_5xx_reported_as_outage(self):
+        msg = _format_upstream_error(503, "", "https://api.deepseek.com")
+        assert msg == "DeepSeek is having an outage (HTTP 503)."
+
+    def test_other_status_passthrough(self):
+        msg = _format_upstream_error(418, "", "https://api.openai.com/v1")
+        assert msg == "OpenAI returned HTTP 418"
+
+    def test_string_error_field(self):
+        msg = _format_upstream_error(401, '{"error": "bad key"}', "https://api.openai.com/v1")
+        assert "bad key" in msg
+
+    def test_plain_text_body_used_as_detail(self):
+        msg = _format_upstream_error(500, "upstream exploded", "https://api.openai.com/v1")
+        assert "OpenAI is having an outage (HTTP 500)." in msg
+        assert "upstream exploded" in msg
+
+    def test_bytes_body_is_decoded(self):
+        msg = _format_upstream_error(
+            401, b'{"error": {"message": "nope"}}', "https://api.openai.com/v1"
+        )
+        assert "nope" in msg
+
+    def test_unknown_url_falls_back_to_generic_label(self):
+        msg = _format_upstream_error(401, "", "")
+        assert msg.startswith("provider rejected the API key")