Archery Apprentice Documentation

round-vm-refactor-readme

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RoundViewModel Refactor Plan

Overview

The RoundViewModel.kt is a 3,013-line god class that needs safe, incremental refactoring while maintaining runtime behavior.

Current Package Layout

Main Implementation

  • app/src/main/java/com/archeryapprentice/ui/roundScoring/RoundViewModel.kt (3,013 lines)

Test Files

  • app/src/test/java/com/archeryapprentice/ui/roundScoring/RoundViewModelTest.kt
  • app/src/test/java/com/archeryapprentice/ui/roundScoring/RoundViewModelTestBase.kt
  • app/src/test/java/com/archeryapprentice/ui/roundScoring/RoundViewModelDisplayDataTest.kt
  • app/src/test/java/com/archeryapprentice/ui/roundScoring/RoundViewModelMuScoreTest.kt
  • app/src/test/java/com/archeryapprentice/ui/roundScoring/RoundViewModelMuMaxScoreTest.kt
  • app/src/test/java/com/archeryapprentice/ui/roundScoring/RoundViewModelTeamScaffoldingTest.kt
  • app/src/test/java/com/archeryapprentice/rounds/RoundViewModelHelperTest.kt
  • app/src/androidTest/java/com/archeryapprentice/ui/roundScoring/RoundViewModelMp2x3SanityTest.kt

Target Package Layout

Core ViewModels (New)

com.archeryapprentice.ui.roundScoring.viewmodels/
├── RoundViewModel.kt                    # Main coordinator (reduced size)
├── RoundCreationViewModel.kt           # Round setup and creation
├── RoundScoringViewModel.kt            # Arrow scoring logic
├── RoundNavigationViewModel.kt         # End/participant navigation
├── RoundDisplayViewModel.kt            # UI state and formatting
├── RoundStatisticsViewModel.kt         # Statistics calculations
└── RoundTeamViewModel.kt               # Multi-participant support

State Management

com.archeryapprentice.ui.roundScoring.state/
├── RoundInputState.kt                  # Form input state
├── RoundDisplayState.kt                # UI display state
├── RoundScoringState.kt                # Scoring state
└── RoundNavigationState.kt             # Navigation state

Business Logic

com.archeryapprentice.ui.roundScoring.domain/
├── RoundCreationUseCase.kt
├── ScoringUseCase.kt
├── StatisticsUseCase.kt
└── ValidationUseCase.kt

Refactor Checklist

Phase 1: Infrastructure Setup ✓

  • Create this documentation
  • Add RefactorFlags.kt with USE_NEW_VMS = false
  • Add :reportCoverage Gradle alias
  • Add CONTRIBUTING notes for coverage

Phase 2: Extract State Classes

  • Move RoundInputState to separate file
  • Extract RoundDisplayState from main class
  • Create RoundScoringState
  • Create RoundNavigationState
  • Update tests for extracted states

Phase 3: Extract Use Cases

  • Create RoundCreationUseCase
  • Create ScoringUseCase
  • Create StatisticsUseCase
  • Create ValidationUseCase
  • Update main ViewModel to use cases
  • Update tests

Phase 4: Extract Specialized ViewModels

  • Create RoundCreationViewModel
  • Create RoundScoringViewModel
  • Create RoundNavigationViewModel
  • Create RoundDisplayViewModel
  • Create RoundStatisticsViewModel
  • Create RoundTeamViewModel

Phase 5: Integration and Cleanup

  • Update UI components to use new ViewModels (gated by RefactorFlags.USE_NEW_VMS)
  • Comprehensive testing of new architecture
  • Enable RefactorFlags.USE_NEW_VMS = true
  • Remove old RoundViewModel code
  • Clean up unused imports and dependencies

Rules

  1. No Runtime Behavior Changes: Each step must maintain identical external behavior
  2. Test Coverage: Run coverage reports before/after each phase
  3. Feature Flags: Use RefactorFlags to gate UI migrations
  4. Incremental: One logical unit at a time
  5. Validation: All existing tests must pass after each step

Success Metrics

  • Reduce main RoundViewModel.kt from 3,013 lines to <500 lines
  • Maintain or improve test coverage (currently at baseline)
  • All existing functionality preserved
  • Improved code maintainability and readability
  • Clear separation of concerns

Source: techdebt/README_RoundVM_Refactor.md
Status: Phase 1 complete, remaining phases planned
See Also: RoundViewModel-Audit for detailed analysis, Refactoring-Reality-Check for actual outcomes

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