# Plan: Issue #108 - Test Coverage Gaps

## Summary
Add comprehensive tests for the modifier system (cache behavior, accumulation, type safety),
integration tests (attribute change -> damage monitor recalculation), and ViewModel-like unit tests
for save/load/error paths. Also add UI tests for edit dialog validation.

## Implementation Steps

1. **ModifierSystemTest.kt** - Tests for:
   - ModifierCache LRU eviction (max 5 entries)
   - ModifierCache cache hit behavior
   - AttributeModifier application to Attributes
   - accumulateModifiers fold for DiceRoll
   - Type safety of modifier interfaces

2. **IntegrationTest.kt** - Tests for:
   - Attribute change -> DamageMonitor max value recalculation
   - Full character round-trip: create, modify attributes, verify derived values
   - Serialization round-trip preserving modifier behavior

3. **CharacterViewModelTest.kt** - Tests for:
   - Save/serialize path (DataLoader.serialize)
   - Load/deserialize path with valid JSON
   - Error handling on malformed JSON (falls back to EXAMPLE_CHARACTER)
   - Character update transform function

4. **EditDialogValidationTest.kt** - Tests for:
   - CharacterData validation (checking field constraints)
   - Attribute edit value bounds

## AC Verification Checklist
1. [ ] ViewModel tests for save/load/error paths
2. [ ] Integration test: modify attribute -> verify damage monitor updates
3. [ ] Modifier system tests: cache hits, accumulation, type safety
4. [ ] UI tests for edit dialogs with validation
5. [ ] Test coverage report available (document how to generate)