fix: fixes vector stage input parsing for aggregate tool MCP-336 #794
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Users were unable to use VectorSearch stage because Zod was using our catch all stage (AnyAggregateStage) before VectorSearchStage to parse and validate even the vector seach stage input and it passed through because that schema is a catch all schema. Because of that, in the input that we received, outputDimension was not transformed ever. This commit changes the order of application of schema so that VectorSeachStage schema is validated first and then the catch all stage schema.
Contributor
There was a problem hiding this comment.
Pull request overview
This PR fixes a bug in the aggregate tool where vector search stages with string outputDimension values were not being properly transformed to numbers. The issue occurred because Zod's catch-all AnyAggregateStage schema was evaluated before the more specific VectorSearchStage schema, preventing proper validation and transformation.
Key Changes:
- Reordered union schema evaluation to prioritize
VectorSearchStageoverAnyAggregateStage - Added comprehensive integration tests to verify
outputDimensionstring-to-number transformation
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| src/tools/mongodb/read/aggregate.ts | Fixed schema union order to evaluate VectorSearchStage before AnyAggregateStage |
| tests/integration/tools/mongodb/read/aggregate.test.ts | Added integration tests for outputDimension transformation and moved import to top of file |
fmenezes
approved these changes
Dec 11, 2025
Collaborator
Pull Request Test Coverage Report for Build 20130214852Details
💛 - Coveralls |
himanshusinghs
deleted the
fix/MCP-336-fixes-aggregate-vector-search-stage
branch
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Proposed changes
Users were unable to use VectorSearch stage because Zod was using our catch all stage (AnyAggregateStage) before VectorSearchStage to parse and validate even the vector search stage input and it passed through because that schema is a catch all schema.
Because of that, in the input that we received, outputDimension was not transformed ever.
This commit changes the order of application of schema so that VectorSearchStage schema is validated first and then the catch all stage schema.
Checklist