fix(aztec-node): throw on existing nullifier in getLowNullifierMembershipWitness#21472
Merged
PhilWindle merged 2 commits intomerge-train/fairiesfrom Mar 16, 2026
Merged
Conversation
benesjan
commented
Mar 13, 2026
| } | ||
|
|
||
| /** | ||
| * Returns a low nullifier membership witness for a given nullifier at a given block. |
Contributor
Author
There was a problem hiding this comment.
dropped the docs from here as they were a duplicate of docs from AztecNode and I think these duplicates are bad (they can become stale).
benesjan
commented
Mar 13, 2026
| }); | ||
| }); | ||
|
|
||
| describe('getLowNullifierMembershipWitness', () => { |
Contributor
Author
There was a problem hiding this comment.
Added 2 tests here. Otherwise this is not unit tested at all. (not the scope of fairies team)
… nullifier exists Previously, getLowNullifierMembershipWitness would log a warning and return the nullifier's own witness when it already existed in the tree. This is wrong for a non-inclusion proof and led to cryptic circuit assertion failures downstream. Now it throws a descriptive error early. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
benesjan
force-pushed
the
be/fix-low-nullifier-witness-error
branch
from
dd3ea83 to
4639347
Compare
Contributor
Author
This stack of pull requests is managed by Graphite. Learn more about stacking. |
PhilWindle
approved these changes
Mar 16, 2026
This was referenced Mar 16, 2026
github-merge-queue bot
pushed a commit
that referenced
this pull request
Mar 16, 2026
BEGIN_COMMIT_OVERRIDE feat: add public log filtering by tag (#21561) feat: default to kernelless simulations (#21575) fix(aztec-node): throw on existing nullifier in getLowNullifierMembershipWitness (#21472) fix: update nullifier non-inclusion test expectations after early oracle throw (#21600) refactor(pxe): type and audit legacy oracle mappings (#21569) END_COMMIT_OVERRIDE
AztecBot
pushed a commit
that referenced
this pull request
Mar 17, 2026
…shipWitness (#21472) As I was going through TODOs I found this ancient TODO of mine (from November 2023): ``` * Note: This function returns the membership witness of the nullifier itself and not the low nullifier when * the nullifier already exists in the tree. This is because the `getPreviousValueIndex` function returns the * index of the nullifier itself when it already exists in the tree. * TODO: This is a confusing behavior and we should eventually address that. ``` In this PR i handle it by instead throwing an error in this scenario. This doesn't modify the interface so it was not urgent to do but felt like it makes sense to do now anyway so I went with it. (Pinged this PR to alpha team) ## Summary - `getLowNullifierMembershipWitness` now throws a descriptive error when the queried nullifier already exists in the tree, instead of silently returning the nullifier's own witness (which is wrong for a non-inclusion proof) - Removes the long-standing TODO about confusing behavior (open since Nov 2023) - Adds `@throws` JSDoc to both the interface and implementation - Adds unit tests for the throw and undefined-return paths ## Context Previously, `getPreviousValueIndex` returns the nullifier's own index when `alreadyPresent: true`. The method just logged a warning and returned that witness anyway. The Noir circuit would catch this implicitly (the `low < target` assertion fails), but the error surfaced as a cryptic circuit assertion rather than a clear "nullifier already exists" message. ## Test plan - Unit tests added in `server.test.ts` covering both the throw-on-exists and return-undefined paths - All 34 existing tests in `server.test.ts` continue to pass - Build, format, and lint pass 🤖 Generated with [Claude Code](https://claude.com/claude-code)
Collaborator
|
✅ Successfully backported to backport-to-v4-next-staging #21654. |
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
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.
As I was going through TODOs I found this ancient TODO of mine (from November 2023):
In this PR i handle it by instead throwing an error in this scenario.
This doesn't modify the interface so it was not urgent to do but felt like it makes sense to do now anyway so I went with it.
(Pinged this PR to alpha team)
Summary
getLowNullifierMembershipWitnessnow throws a descriptive error when the queried nullifier already exists in the tree, instead of silently returning the nullifier's own witness (which is wrong for a non-inclusion proof)@throwsJSDoc to both the interface and implementationContext
Previously,
getPreviousValueIndexreturns the nullifier's own index whenalreadyPresent: true. The method just logged a warning and returned that witness anyway. The Noir circuit would catch this implicitly (thelow < targetassertion fails), but the error surfaced as a cryptic circuit assertion rather than a clear "nullifier already exists" message.Test plan
server.test.tscovering both the throw-on-exists and return-undefined pathsserver.test.tscontinue to pass🤖 Generated with Claude Code