Consolidate TypeScript types into centralized /app/types directory

[DevinByteX]

🎯 Objective

Consolidate all TypeScript type definitions from scattered locations into a centralized /app/types directory structure to improve maintainability, eliminate circular dependencies, and establish a single source of truth for type definitions.

📋 Current State

Types are currently scattered across multiple locations:

• context/types.ts - App state and action types
• configs/constants.ts - Configuration types (CurrencyType, DuplicatePreventionTimeOption)
• Various hook files - Hook-specific types
• Component files - Component-specific types
• /app/types directory exists but is empty

Circular Dependency Issue

• context/types.ts imports CurrencyType from @configs
• configs/constants.ts imports types from @/context/types
• This creates a problematic circular dependency

🏗️ Proposed Structure

app/types/
  ├── index.ts          # Export all types (single entry point)
  ├── app.types.ts      # AppState, Actions, etc.
  ├── config.types.ts   # CurrencyType, DuplicatePreventionTimeOption, SliderConfigs
  └── tip.types.ts      # TipOptionState, SplitOptionState, SavedTip

✅ Implementation Steps

1. Create Type Definition Files

config.types.ts

Move from configs/constants.ts and context/types.ts:

• CurrencyType
• DuplicatePreventionTimeOption
• TipSliderConfigValues
• SplitSliderConfigValues

tip.types.ts

Move from context/types.ts:

• TipOptionState
• SplitOptionState
• SavedTip

Optional: Consider adding hook-related types:

• BillCalculationResult
• RoundingDirection
• RoundingMethod
• RoundingMethodAvailability

app.types.ts

Move from context/types.ts:

• AppState
• TipAction
• SplitAction
• CurrencyConfigAction
• SavedTipAction
• DuplicatePreventionAction
• AppAction

index.ts

Re-export all types from the three category files.

2. Update tsconfig.json

Add path alias for the new types directory:

"@types": ["app/types/index"]

3. Update Import Statements

Update all files (17+ files) that currently import from @/context/types or type imports from @configs:

Context files:

• context/AppContext.tsx
• context/reducers.ts
• context/rootReducer.ts

Hook files:

• hooks/useSaveTip.ts
• hooks/asyncStorageHooks.ts
• hooks/asyncStorageUtil.ts
• hooks/usePersistedReducer.ts

Component files:

• components/StyledSplitOptions/index.tsx
• components/StyledSplitOptionsEditMode/index.tsx
• components/StyledTipOptions/index.tsx
• components/StyledTipOptionsEditMode/index.tsx
• components/StyledCurrencySelector/index.tsx
• components/StyledDuplicatePreventionSelector/index.tsx

Screen files:

• screens/TipScreens/SavedTipsListScreen.tsx
• screens/TipScreens/SavedTipDetailScreen.tsx
• screens/TipScreens/TipMainScreen.tsx

Config files:

• configs/constants.ts (remove type definitions, import from @types)

4. Clean Up

• Delete context/types.ts after migration is complete

5. Verification

• Run TypeScript compilation: tsc --noEmit
• Verify the app builds successfully
• Test core functionality (tip calculations, settings, saved tips)

🔮 Future Considerations

1. Hook-specific types: Should types like ThemeCustomisationState, ExternalLinkAlertConfig, and ShareTipDetailsParams be moved to /app/types/hook.types.ts, or remain co-located with their implementations?

2. Component types: Should component-specific types (e.g., AlertType, IconProps) be moved to /app/types/component.types.ts?

3. Navigation types: Consider creating navigation.types.ts to centralize route parameters (like SavedTipDetailScreenParams) for type-safe navigation.

✨ Benefits

• ✅ Single source of truth for all type definitions
• ✅ Eliminates circular dependencies
• ✅ Easier to find and update types
• ✅ Better code organization and maintainability
• ✅ Clearer separation between types and implementation
• ✅ Prevents future circular dependency issues

📝 Notes

• This is a refactoring task with no functional changes
• All type definitions remain the same, only their location changes
• Existing functionality should remain unchanged
• Consider this a foundation for better type organization going forward