[**BestPractice**]

The logic for creating a `CollectionImpl` instance from an API response is repeated in `listCollections`, `createCollection`, `getCollection`, and `getOrCreateCollection`. To improve maintainability and reduce code duplication, consider extracting this logic into a private helper method, for example `_collectionFromResponseData(data, embeddingFunction?)`. This would centralize the construction of collection objects from API data.

**ChromaDB Best Practice**: Following the official ChromaDB JavaScript client patterns, API responses should be consistently transformed into Collection objects. A helper method ensures consistent handling of the API response structure and metadata across all collection operations.

File: clients/new-js/packages/chromadb/src/chroma-client.ts
Line: 232

[**BestPractice**]

The new `schema.ts` file is quite large and contains many distinct concepts (constants, config classes, type classes, utility functions, and the main `Schema` class). For better maintainability and code organization, consider splitting this file into smaller, more focused modules. 

For example, you could structure it like this:
- `src/schema/constants.ts`
- `src/schema/index-configs.ts`
- `src/schema/value-types.ts`
- `src/schema/utils.ts`
- `src/schema/schema.ts` (for the main class)
- `src/schema/index.ts` (to re-export everything)

This would make the code easier to navigate and understand.

File: clients/new-js/packages/chromadb/src/schema.ts
Line: 1

[**BestPractice**]

Array length validation missing: If `sparseEmbeddings.length !== positions.length`, the error is thrown but the actual values aren't included in the error message, making debugging difficult.

<details>
<summary>Suggested Change</summary>

```suggestion
if (sparseEmbeddings.length !== positions.length) {
  throw new ChromaValueError(
    `Sparse embedding function returned unexpected number of embeddings. Expected ${positions.length}, got ${sparseEmbeddings.length}`,
  );
}
```

⚡ **Committable suggestion**

Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation.

</details>

File: clients/new-js/packages/chromadb/src/collection.ts
Line: 415

[**BestPractice**]

Same issue: include actual vs expected values in error message for better debugging.

<details>
<summary>Suggested Change</summary>

```suggestion
if (sparseEmbeddings.length !== positions.length) {
  throw new ChromaValueError(
    `Sparse embedding function returned unexpected number of embeddings. Expected ${positions.length}, got ${sparseEmbeddings.length}`,
  );
}
```

⚡ **Committable suggestion**

Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation.

</details>

File: clients/new-js/packages/chromadb/src/collection.ts
Line: 452

[**BestPractice**]

This function is quite long and contains duplicated logic for handling `sourceKey === DOCUMENT_KEY` and the general case where `sourceKey` is a metadata field. The core logic of collecting inputs, generating embeddings, and updating metadata is nearly identical in both branches.

Consider extracting this shared logic into a helper function to reduce duplication and improve readability. The helper could take parameters like `targetKey`, `config`, `updatedMetadatas`, and `documentsList` and handle the embedding process for a single sparse target. This would make `applySparseEmbeddingsToMetadatas` much simpler, as it would then be primarily responsible for iterating through `sparseTargets` and calling the helper.

File: clients/new-js/packages/chromadb/src/collection.ts
Line: 362

[**BestPractice**]

The logic in `resolveSchemaEmbeddingFunction` is duplicated in `clients/new-js/packages/chromadb/src/collection.ts` (lines 473-487) as `getSchemaEmbeddingFunction`. To adhere to the DRY principle, this logic should be extracted into a single, shared function. A good location for this would be the new `schema.ts` file, as it's directly related to schema interpretation and follows ChromaDB's TypeScript architectural patterns.

Additionally, the use of `?? undefined` is redundant since optional chaining (`?.`) already results in `undefined` if any part of the chain is nullish.

Here's a suggested implementation for a shared function in `schema.ts`:

```typescript
// in clients/new-js/packages/chromadb/src/schema.ts
export const resolveSchemaEmbeddingFunction = (
  schema: Schema | undefined,
): EmbeddingFunction | undefined => {
  if (!schema) {
    return undefined;
  }

  return (
    schema.keys[EMBEDDING_KEY]?.floatList?.vectorIndex?.config.embeddingFunction ??
    schema.defaults.floatList?.vectorIndex?.config.embeddingFunction
  );
};
```

This refactoring aligns with ChromaDB's TypeScript patterns where embedding functions are modular and reusable components. The new function can then be imported and used in both `chroma-client.ts` and `collection.ts`, removing the duplicated implementations and improving maintainability.

File: clients/new-js/packages/chromadb/src/chroma-client.ts
Line: 41

[**BestPractice**]

This line can be simplified. The check `metadata !== null && metadata !== undefined` can be shortened to `metadata != null`, which checks for both `null` and `undefined`.

```suggestion
      metadata != null ? { ...metadata } : {}
```

⚡ **Committable suggestion**

Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation.

File: clients/new-js/packages/chromadb/src/collection.ts
Line: 378

[**BestPractice**]

The `console.warn` calls were removed from this function for cases where `efConfig` is missing or has type `legacy`. However, `getEmbeddingFunction` still includes these warnings. For a better developer experience and consistency, it would be helpful to add the warnings back to `getSparseEmbeddingFunction`. This would alert developers when a sparse embedding function is configured but cannot be instantiated, which could otherwise lead to silent failures or unexpected behavior.

**ChromaDB Context**: Both dense and sparse embedding functions in ChromaDB follow similar configuration patterns. Consistent warning messages across both types help developers quickly identify and resolve embedding function configuration issues, especially when working with legacy configurations or missing parameters.

File: clients/new-js/packages/chromadb/src/embedding-function.ts
Line: 248