fix: resolve FBD editor infinite render loop causing high CPU

[thiagoralves]

Summary

• Strip hasDivergence UI property from store comparisons in updateRungState to prevent isEqual mismatch (undefined vs false) that triggered a continuous render loop
• Use selective Zustand selectors in FbdEditor wrapper instead of whole-store destructuring to avoid unnecessary re-renders
• Memoize divergence computation with useMemo to prevent recalculation on every render
• Narrow styledEdges dependencies from entire project object to only pouRef?.data.variables and project.data.configuration.resource.instances

These are the same fixes applied in openplc-web (PR #266, merged).

Root Cause

The hasDivergence property was set on nodes for UI display but leaked into store comparisons. isEqual({hasDivergence: undefined}, {hasDivergence: false}) always returned false, causing updateRungState to write back to the store on every comparison cycle, which triggered flow.updated = true → updatePou → pous change → FbdEditor re-render → loop.

Test plan

• Open a large FBD diagram and verify CPU usage stays low (~0% idle)
• Verify FBD blocks still display divergence indicators correctly
• Verify variable sync still works when editing the variable table
• Test adding, removing, and connecting FBD blocks
• Verify save/load cycle preserves FBD flow data

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Fixed variable type filtering in autocomplete to properly handle mixed-case entries in restrictions.
  • Improved variable type restriction checks to handle both array and non-array values robustly.

• Performance

  • Optimized component rendering with memoization to reduce unnecessary recalculations.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: dfb87791-2d3b-4928-b770-d137a38a5257

📥 Commits

Reviewing files that changed from the base of the PR and between e414315 and 9f13289.

📒 Files selected for processing (4)

• src/renderer/components/_atoms/graphical-editor/fbd/autocomplete/index.tsx
• src/renderer/components/_atoms/graphical-editor/ladder/autocomplete/index.tsx
• src/renderer/components/_features/[workspace]/editor/graphical/FBD/index.tsx
• src/renderer/components/_molecules/graphical-editor/fbd/index.tsx

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Walkthrough

The PR fixes case-sensitivity issues in autocomplete variable type filtering across FBD and ladder editors, and refactors divergence calculation logic in FBD components using memoization while introducing data cleaning to strip divergence flags from node state.

Changes

Cohort / File(s)	Summary
Autocomplete Variable Type Filtering src/renderer/components/_atoms/graphical-editor/fbd/autocomplete/index.tsx, src/renderer/components/_atoms/graphical-editor/ladder/autocomplete/index.tsx	Standardize variable type restriction checks by normalizing comparison values to lowercase and handling both array and non-array value formats for robust case-insensitive matching.
FBD Divergence Calculation & Optimization src/renderer/components/_features/[workspace]/editor/graphical/FBD/index.tsx, src/renderer/components/_molecules/graphical-editor/fbd/index.tsx	Refactor divergence computation into memoized selectors, introduce stripDivergence helper to remove hasDivergence flag from node data during rung updates, and optimize styledEdges memoization dependencies.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

Possibly related PRs

• fix: Allow custom data types in FBD variable nodes #516 — Modifies the same FBD autocomplete variable-type filtering logic in the same file with similar case-sensitivity fixes.
• DOPE-135: Block update trigger fires incorrectly on variable modification #331 — Refactors divergence-detection logic in FBD/ladder graphical editor with comparable memoization and computation changes.
• fix: resolve debugger issues with simulator endianness, FBD visualization, and forced variable polling #635 — Adjusts styledEdges useMemo dependency handling in the same FBD molecule component file.

Suggested labels

bug

Suggested reviewers

• JoaoGSP
• Gustavohsdp

Poem

🐰 A fix for case and divergence woes,
Where rabbit code now cleaning flows,
Memoized logic, fast and bright,
Autocomplete works just right,
No more confusion, side to side! ✨

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