fix(proxy): preserve dict guardrail HTTPException.detail + bedrock context (#25558)

tests/test_litellm/proxy/test_proxy_utils.py

@@ -190,3 +190,79 @@ def test_get_projected_spend_over_limit_includes_current_spend(monkeypatch):
     projected_spend, projected_exceeded_date = result
     assert projected_spend == 290.0
     assert projected_exceeded_date == real_datetime.date(2026, 4, 21)
+
+
+# ---------------------------------------------------------------------------
+# L2: _enrich_http_exception_with_guardrail_context
+# Regression coverage for case 2026-04-10-internal-bedrock-guardrail-streaming-error.
+# ---------------------------------------------------------------------------
+
+
+def test_enrich_http_exception_with_guardrail_context_dict_detail():
+    """L2: dict-detail HTTPException is enriched with guardrail_name and mode."""
+    from litellm.proxy.utils import _enrich_http_exception_with_guardrail_context
+
+    class StubCallback:
+        guardrail_name = "bedrock-pii-guard"
+        event_hook = "post_call"
+
+    exc = HTTPException(
+        status_code=400, detail={"error": "Violated guardrail policy"}
+    )
+    _enrich_http_exception_with_guardrail_context(exc, StubCallback())
+    assert exc.detail["guardrail_name"] == "bedrock-pii-guard"
+    assert exc.detail["guardrail_mode"] == "post_call"
+
+
+def test_enrich_http_exception_string_detail_noop():
+    """L2: string-detail HTTPException is not mutated (can't add fields to a str)."""
+    from litellm.proxy.utils import _enrich_http_exception_with_guardrail_context
+
+    class StubCallback:
+        guardrail_name = "x"
+        event_hook = "pre_call"
+
+    exc = HTTPException(status_code=400, detail="Content blocked")
+    _enrich_http_exception_with_guardrail_context(exc, StubCallback())
+    assert exc.detail == "Content blocked"
+
+
+def test_enrich_http_exception_setdefault_does_not_overwrite():
+    """L2: a guardrail that already populates guardrail_name explicitly wins."""
+    from litellm.proxy.utils import _enrich_http_exception_with_guardrail_context
+
+    class StubCallback:
+        guardrail_name = "inferred-name"
+        event_hook = "pre_call"
+
+    exc = HTTPException(
+        status_code=400,
+        detail={"error": "x", "guardrail_name": "explicit-name"},
+    )
+    _enrich_http_exception_with_guardrail_context(exc, StubCallback())
+    assert exc.detail["guardrail_name"] == "explicit-name"
+
+
+def test_enrich_http_exception_non_http_exception_noop():
+    """L2: non-HTTPException is left alone and the helper does not raise."""
+    from litellm.proxy.utils import _enrich_http_exception_with_guardrail_context
+
+    class StubCallback:
+        guardrail_name = "x"
+        event_hook = "pre_call"
+
+    exc = ValueError("not an HTTPException")
+    _enrich_http_exception_with_guardrail_context(exc, StubCallback())
+    assert str(exc) == "not an HTTPException"
+
+
+def test_enrich_http_exception_callback_without_guardrail_name_noop():
+    """L2: callback without guardrail_name attribute leaves detail alone."""
+    from litellm.proxy.utils import _enrich_http_exception_with_guardrail_context
+
+    class StubCallback:
+        pass
+
+    exc = HTTPException(status_code=400, detail={"error": "x"})
+    _enrich_http_exception_with_guardrail_context(exc, StubCallback())
+    assert exc.detail == {"error": "x"}