@qin-ctx Please review and merge this

#702 is megred for query and document embedding support.

get_query_embedder() is not the expected usage.

btw check if you can improve based on #718

Thanks for the thorough review! All issues addressed in commit bcfd612:

@qin-ptr — blocking fixes

• B1 __init__.py:15: Fixed — annotation now reads "Dense only (text-only; multimodal planned)"
• B2 Design mismatch: Reframed PR as Phase 1 (text-only). Changed "Closes: [Feature]: Add first-class Gemini Embedding 2 support for multimodal retrieval #566" → "Partial implementation of [Feature]: Add first-class Gemini Embedding 2 support for multimodal retrieval #566". Issue stays open for Phase 2 (multimodal).
• B3 Lint: Ran black on test_gemini_embedder.py

@qin-ptr — non-blocking (adopted both)

• NB1 task_type normalization: Added auto-uppercase in sync_provider_backend for task_type, query_param, document_param. Users can now write task_type: "retrieval_document" (any case) in config. Added test test_gemini_task_type_case_insensitive.
• NB2 Empty text warning: Added logger.warning("Empty text passed to embed(), returning zero vector")

@ZaynJarvis — #702 pattern + #718

• feat(embedding): combine document embedder and query embedder to avoi… #702 pattern: Already implemented ✅ — factory at embedding_config.py:370-384 does context-based task_type routing via get_query_embedder() / get_document_embedder() / _get_contextual_embedder(). Non-symmetric mode activates when query_param or document_param is set in config.
• feat: add native Google/Gemini Embedding 2 support with Parts API #718 alignment: Reviewed. Our SDK-based approach (google-genai) vs feat: add native Google/Gemini Embedding 2 support with Parts API #718's raw REST approach are complementary. Phase 2 multimodal work will incorporate Parts API structure from feat: add native Google/Gemini Embedding 2 support with Parts API #718. If feat: add native Google/Gemini Embedding 2 support with Parts API #718 merges first, we'll consolidate file naming (google_embedders.py vs gemini_embedders.py).

Verification

ruff check: All checks passed!
pytest: 59 passed (41 embedder + 18 config, incl. 1 new normalization test)
black --check: 1 file would be left unchanged

@qin-ctx Can we merge? Main keeps changing now tests are working

for query and document embedding

    def get_query_embedder(self):
        """Get embedder instance for query embeddings."""
        return self._get_contextual_embedder("query")

    def get_document_embedder(self):
        """Get embedder instance for document/passage embeddings."""
        return self._get_contextual_embedder("document")

    def _get_contextual_embedder(self, context: str):
        if not self.dense:
            return self.get_embedder()

        provider = (self.dense.provider or "").lower()
        if provider == "openai":
            non_symmetric = (
                self.dense.query_param is not None or self.dense.document_param is not None
            )
            effective_context = context if non_symmetric else None
            return self._create_embedder(provider, "dense", self.dense, context=effective_context)

        if provider == "jina":
            return self._create_embedder(provider, "dense", self.dense, context=context)

        if provider == "gemini":
            non_symmetric = (
                self.dense.query_param is not None or self.dense.document_param is not None
            )
            effective_context = context if non_symmetric else None
            return self._create_embedder(provider, "dense", self.dense, context=effective_context)

        return self.get_embedder()

this is removed in purpose in #702 and replaced by

@abstractmethod
    def embed(self, text: str, is_query: bool = False)

please remove the _get_contextual_embedder etc. and use is_query

2. [note, no need to change] after discovering, gemini embedding 1 supports taskType, gemini embedding 2 ignores taskType in request.

for gemini embedding 2, recommended task type instruction is through prompt instruction, e.g. embedding prompt: "taskType: {taskType}, content: {content}"

others lgtm, if this PR changes 1, i will merge and closes #718

@ZaynJarvis Fixed per #702:

• Removed get_query_embedder() / get_document_embedder() / _get_contextual_embedder() + context param — none of these exist in this PR
• GeminiDenseEmbedder now accepts query_param / document_param in constructor
• embed(text, is_query=True) selects query_param; is_query=False selects document_param — same pattern as OpenAI._build_extra_body(is_query) and Jina._build_extra_body(is_query)
• Rebased onto current main (clean single commit on top of upstream/main)
• Tests: 58 unit tests pass, integration tests skip cleanly without API key

pls fix workflow

Addressed round 2 feedback:

1. Removed task_type from EmbeddingModelConfig — query_param/document_param already contain the task type.
2. Fixed CI — wrapped GeminiDenseEmbedder import in try/except ImportError since google-genai is an optional dependency.
3. Updated tests accordingly (removed 4 task_type-specific config tests).

All unit tests pass locally (54/54 Gemini tests green).

Doc might need to be updated for Gemini usage. google genai pkg needs to be installed. Consider a follow up PR for this. Thx.