[ENH]: Disallow setting only source_key without an ef

[sanketkedia]

Description of changes

Summarize the changes made by this PR.

• Improvements & Bug fixes
  • Setting only source_key without an ef in the sparse vector index config now returns an error
• New functionality
  • ...

Test plan

How are these changes tested?

• Tests pass locally with pytest for python, yarn test for js, cargo test for rust

Migration plan

Are there any migrations, or any forwards/backwards compatibility changes needed in order to make sure this change deploys reliably?

Observability plan

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Documentation Changes

Are all docstrings for user-facing APIs updated if required? Do we need to make documentation changes in the docs section?

[sanketkedia]

• [ENH]: Disallow setting only source_key without an ef #5758 👈 (View in Graphite)
• main

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[github-actions]

Reviewer Checklist

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Testing, Bugs, Errors, Logs, Documentation

• Can you think of any use case in which the code does not behave as intended? Have they been tested?
• Can you think of any inputs or external events that could break the code? Is user input validated and safe? Have they been tested?
• If appropriate, are there adequate property based tests?
• If appropriate, are there adequate unit tests?
• Should any logging, debugging, tracing information be added or removed?
• Are error messages user-friendly?
• Have all documentation changes needed been made?
• Have all non-obvious changes been commented?

System Compatibility

• Are there any potential impacts on other parts of the system or backward compatibility?
• Does this change intersect with any items on our roadmap, and if so, is there a plan for fitting them together?

Quality

• Is this code of a unexpectedly high quality (Readability, Modularity, Intuitiveness)

[propel-code-bot]

Add validation: require embedding_function when source_key is set on SparseVectorIndexConfig

This PR introduces defensive validation in both Python (chromadb/api/types.py) and Rust (rust/types/src/validators.rs) layers to prevent mis-configuration of sparse vector indexes. A ValueError (Python) / ValidationError (Rust) is now raised if source_key is provided without an accompanying embedding_function, since the system has no default sparse embedding function. Corresponding unit tests are updated and a new test is added to assert the error behaviour.

Key Changes

• Added _validate_sparse_vector_config helper and integrated it into _set_index_for_key and _enable_all_indexes_for_key in chromadb/api/types.py
• Parallel check added in Rust validator (validators.rs) for schema validation
• Updated multiple test cases to include MockSparseEmbeddingFunction; added test_sparse_vector_config_requires_ef_with_source_key

Affected Areas

• Schema.create_index path for sparse vectors (Python)
• Schema validation logic (Rust)
• Test suite for schema validation

This summary was automatically generated by @propel-code-bot