perf: FIT-1302: Fix non-deterministic React keys causing unnecessary remounts#9268
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perf: FIT-1302: Fix non-deterministic React keys causing unnecessary remounts#9268
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Replace non-deterministic and index-based keys with stable identifiers to improve React reconciliation performance. Critical fixes: - App.jsx: Replace guidGenerator() with stable 'relations-overlay' key (was causing RelationsOverlay to remount on every parent render) - PolygonRegion.jsx: Remove guidGenerator() fallback, use item.id only High-frequency component fixes: - SidePanels.tsx: Use Component.displayName/name instead of index - OutlinerTree.tsx: Use tag.name or tag.type instead of index - Grid.jsx: Use selected.id instead of loop index - TextAreaRegionView.jsx: Use item.id with line index for stability Using array index as key causes React to incorrectly diff when items are added, removed, or reordered. Using guidGenerator() creates a new key every render, forcing complete remount of the component tree.
Codecov Report✅ All modified and coverable lines are covered by tests.
Additional details and impacted files@@ Coverage Diff @@
## develop #9268 +/- ##
===========================================
- Coverage 66.82% 57.91% -8.92%
===========================================
Files 830 561 -269
Lines 64879 40547 -24332
Branches 10971 11008 +37
===========================================
- Hits 43355 23481 -19874
+ Misses 21520 17062 -4458
Partials 4 4
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Problem
Two critical anti-patterns in React key usage:
guidGenerator()as key - Creates a new key on every render, forcing React to completely unmount and remount the component. Found inApp.jsxforRelationsOverlay.Array index as key - Causes incorrect diffing when items are added, removed, or reordered. Found in multiple components.
Solution
Replace non-deterministic keys with stable identifiers:
App.jsxkey={guidGenerator()}key="relations-overlay"Grid.jsxkey={i}key={selected.id}SidePanels.tsxkey={i}key={Component.displayName}OutlinerTree.tsxkey={idx}key={tag.name}PolygonRegion.jsxkey={item.id || guidGenerator()}key={item.id}TextAreaRegionView.jsxkey={idx}key={\${item.id}-line-${idx}`}`Files Changed
web/libs/editor/src/components/App/App.jsxweb/libs/editor/src/components/App/Grid.jsxweb/libs/editor/src/components/SidePanels/SidePanels.tsxweb/libs/editor/src/components/SidePanels/OutlinerPanel/OutlinerTree.tsxweb/libs/editor/src/regions/PolygonRegion.jsxweb/libs/editor/src/tags/control/TextArea/TextAreaRegionView.jsx