Phase 7: Cleanup

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Effort: 1-2 hours Risk: Low Priority: Required (after toggle has been defaulted to ON) Previous: Phase 6: Duplicate Index Calls

Goal

Clean up feature flag infrastructure after successful adoption. Remove legacy code, rename refactored files, and finalize the implementation.

When to Do This

Only after:

• Toggle defaulted to ON for 1+ week and PM approved

• No issues reported

• All metrics stable

• Team confidence is high

Steps

5.1 Remove Feature Flag

File: toggles/webapp/app/toggles.ts

// DELETE:
iiifViewerRefactored: {
  id: 'iiifViewerRefactored',
  title: 'IIIF Viewer - Refactored Context',
  defaultValue: false,
  description: 'Use refactored ItemViewerContext with centralised derived values',
},

5.2 Delete Legacy Files

cd content/webapp/views/pages/works/work/IIIFViewer

# Delete all .legacy.tsx files
rm IIIFViewer.legacy.tsx
rm ViewerTopBar.legacy.tsx
rm ZoomedImage.legacy.tsx
rm MainViewer.legacy.tsx
# ... any other .legacy.tsx files

Also remove types that are not in use anymore.

5.3 Rename Refactored Files to Standard Names

# Rename .refactored.tsx to .tsx
mv IIIFViewer.refactored.tsx IIIFViewer.tsx
mv ViewerTopBar.refactored.tsx ViewerTopBar.tsx
mv ZoomedImage.refactored.tsx ZoomedImage.tsx
mv MainViewer.refactored.tsx MainViewer.tsx

5.4 Delete Wrapper Component

# No longer needed - IIIFViewer.tsx is now the main component
rm index.tsx  # The wrapper that switched between legacy/refactored

5.5 Rename Context

# Delete old context
rm -rf content/webapp/contexts/ItemViewerContext

# Rename new context to standard name
mv content/webapp/contexts/ItemViewerContextV2 \
   content/webapp/contexts/ItemViewerContext

5.6 Update All Imports

Replace all occurrences of ItemViewerContextV2 with ItemViewerContext:

# Find all imports
grep -r "ItemViewerContextV2" content/webapp

# Update each file:
# OLD: import ItemViewerContextV2 from '@weco/common/contexts/ItemViewerContextV2';
# NEW: import ItemViewerContext from '@weco/common/contexts/ItemViewerContext';

5.7 Remove Unused Props

Identify components that can drop props now that context provides the data:

// Example: ViewerTopBar might have received props that context now provides
// Remove those props from the interface and component

5.8 Update Tests

Rename test files and update imports:

mv ItemViewerContextV2.test.tsx ItemViewerContext.test.tsx
mv IIIFViewer.refactored.test.tsx IIIFViewer.test.tsx
# Update imports in test files from V2 to standard

5.9 Type Cleanup

Ensure all TypeScript types reflect the final context shape. Remove any temporary types used during migration.

5.10 Documentation

• Update inline comments if needed

• Remove any "TODO: remove after refactor" comments

• Update component documentation if it references old structure

Success Criteria

• No more .legacy.tsx files

• No more .refactored.tsx files

• No ItemViewerContextV2 references

• Feature flag removed from toggles

• All tests still pass

• TypeScript compiles with no errors

• Application runs correctly

• Code is clean and maintainable

Time: 1-2 hours

---

The IIIF Viewer context refactoring is complete!

See also:

• 14-risks-and-success.md - Final success metrics