ENG-1777 - Limit /tree endpoint depth to 4 levels

[vcruces]

Ticket ENG-1777

Description Of Changes

Fixed an issue in the action center tree where nested fields were marked as expandable nodes, causing the UI to attempt to load children that were already loaded at the parent level.

Root cause: The backend uses the StagedResource.children column to determine which resources have children. For nested fields, this column stores a flattened list of all descendants (children, grandchildren, etc.) rather than just direct children. This means when you expand a parent field, you already see all nested fields in the tree. However, those nested fields still appear as expandable themselves, which would just show the same children again.

Solution: The fix ensures that all FIELD type resources are treated as leaf nodes in the tree UI, regardless of what the has_grandchildren flag indicates. This prevents the UI from attempting to expand field-level nodes where the backend would return an unexpected flattened hierarchy.

Code Changes

• Updated MonitorTree.tsx to mark all FIELD resources as leaf nodes (isLeaf: true). This prevents fields with nested children from showing as expandable in the tree UI

Steps to Confirm

• Navigate to a datastore monitor with nested fields
• Expand the tree to the field level
• Verify that fields with nested children no longer show an expand arrow/icon
• Verify that the tree navigation still works correctly for Database → Schema → Table hierarchy
• Confirm that field-level nodes are selectable but not expandable

Pre-Merge Checklist

• Issue requirements met
• All CI pipelines succeeded
• CHANGELOG.md updated
  • Add a db-migration This indicates that a change includes a database migration label to the entry if your change includes a DB migration
  • Add a high-risk This issue suggests changes that have a high-probability of breaking existing code label to the entry if your change includes a high-risk change (i.e. potential for performance impact or unexpected regression) that should be flagged
  • Updates unreleased work already in Changelog, no new entry necessary
• UX feedback:
  • All UX related changes have been reviewed by a designer
  • No UX review needed
• Followup issues:
  • Followup issues created
  • No followup issues
• Database migrations:
  • Ensure that your downrev is up to date with the latest revision on main
  • Ensure that your downgrade() migration is correct and works
    • If a downgrade migration is not possible for this change, please call this out in the PR description!
  • No migrations
• Documentation:
  • Documentation complete, PR opened in fidesdocs
  • Documentation issue created in fidesdocs
  • If there are any new client scopes created as part of the pull request, remember to update public-facing documentation that references our scope registry
  • No documentation updates required

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2 Skipped Deployments

Project	Deployment	Preview	Comments	Updated (UTC)
fides-plus-nightly	Ignored	Preview		Nov 3, 2025 8:35pm
fides-privacy-center	Ignored			Nov 3, 2025 8:35pm

[greptile-apps]

Greptile Overview

Greptile Summary

This PR fixes a UI bug where nested fields in the action center tree were incorrectly showing expand arrows. The root cause was that the backend stores flattened descendants in StagedResource.children, so expanding a parent field already displays all nested fields. The fix adds a check in MonitorTree.tsx:65-67 to treat all FIELD type resources as leaf nodes, preventing the UI from attempting to expand them.

• Fixed tree expansion logic by adding StagedResourceTypeValue.FIELD check to isLeaf determination
• Updated changelog with appropriate description in the "Changed" section

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The change is a straightforward frontend logic fix that adds a simple condition to prevent FIELD resources from being expandable in the tree UI. The logic is sound and addresses the root cause correctly. No breaking changes, backend modifications, or complex state management involved.
• No files require special attention

Important Files Changed

File Analysis

Filename	Score	Overview
clients/admin-ui/src/features/data-discovery-and-detection/action-center/fields/MonitorTree.tsx	5/5	Added logic to treat all FIELD resources as leaf nodes in tree, preventing incorrect expansion of nested fields
CHANGELOG.md	5/5	Added changelog entry documenting the tree depth limitation fix

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[gilluminate]

straight forward improvement