test(kb): regression guard for BibTeX-KB local-embedding routing

tests/unit/test_bibtex_kb_local_embeddings.py

@@ -0,0 +1,48 @@
+"""Regression: BibTeX-import KBs must embed local models via the factory.
+
+Bug: ``pipeline/bibtex_kb.py`` hardcoded ``LiteLLMEmbeddingProvider`` for the embedding
+provider, so a local sentence-transformers model (e.g. the default ``all-MiniLM-L6-v2``)
+was sent to LiteLLM, which raised ``LLM Provider NOT provided`` and produced KBs with 0
+chunks. The fix routes through :func:`create_embedding_provider`, which selects the local
+``SentenceTransformerEmbeddingProvider`` for such models (lazy-loaded, no network).
+"""
+
+from __future__ import annotations
+
+import inspect
+
+from perspicacite.llm.embeddings import (
+    FallbackEmbeddingProvider,
+    LiteLLMEmbeddingProvider,
+    SentenceTransformerEmbeddingProvider,
+    create_embedding_provider,
+)
+
+
+def test_local_minilm_routes_to_sentence_transformer():
+    # the model SentenceTransformerEmbeddingProvider is lazy, so this does not download.
+    provider = create_embedding_provider("all-MiniLM-L6-v2", use_local_fallback=False)
+    assert isinstance(provider, SentenceTransformerEmbeddingProvider)
+    assert provider.model_name == "all-MiniLM-L6-v2"
+
+
+def test_api_model_routes_to_litellm():
+    provider = create_embedding_provider("text-embedding-3-small", use_local_fallback=False)
+    assert isinstance(provider, LiteLLMEmbeddingProvider)
+
+
+def test_api_model_with_local_fallback_is_wrapped():
+    provider = create_embedding_provider("text-embedding-3-small", use_local_fallback=True)
+    assert isinstance(provider, FallbackEmbeddingProvider)
+
+
+def test_bibtex_kb_uses_factory_not_hardcoded_litellm():
+    # Lock the fix: both bibtex-KB builders must use the factory, not LiteLLM directly.
+    from perspicacite.pipeline import bibtex_kb
+
+    for fn in (bibtex_kb.create_kb_from_bibtex, bibtex_kb.add_bibtex_to_existing_kb):
+        src = inspect.getsource(fn)
+        assert "create_embedding_provider(" in src, f"{fn.__name__} should use the factory"
+        assert "LiteLLMEmbeddingProvider(" not in src, (
+            f"{fn.__name__} must not hardcode LiteLLMEmbeddingProvider"
+        )