---
name: improvement
description: |
  Guide for making improvements to existing ClaudeBar functionality using TDD. Use this skill when:
  (1) Enhancing existing features (not adding new ones)
  (2) Improving UX, performance, or code quality
  (3) User asks "improve X", "make Y better", or "enhance Z"
  (4) Small enhancements that don't require full architecture design
  For NEW features, use implement-feature skill instead.
---

# Improve ClaudeBar Feature

Make improvements to existing functionality using TDD and rich domain design.

## When to Use This vs Other Skills

| Scenario | Skill to Use |
|----------|--------------|
| Enhance existing behavior | **improvement** (this skill) |
| Fix broken behavior | fix-bug |
| Add new feature | implement-feature |
| Add new AI provider | add-provider |

## Workflow

```
┌─────────────────────────────────────────────────────────────┐
│  1. UNDERSTAND CURRENT STATE                                 │
├─────────────────────────────────────────────────────────────┤
│  • Read existing code                                        │
│  • Understand current behavior                               │
│  • Identify what to improve                                  │
└─────────────────────────────────────────────────────────────┘
                            │
                            ▼
┌─────────────────────────────────────────────────────────────┐
│  2. WRITE TEST FOR IMPROVED BEHAVIOR (Red)                   │
├─────────────────────────────────────────────────────────────┤
│  • Test describes the IMPROVED behavior                      │
│  • Test should FAIL initially                                │
│  • Keep existing tests passing                               │
└─────────────────────────────────────────────────────────────┘
                            │
                            ▼
┌─────────────────────────────────────────────────────────────┐
│  3. IMPLEMENT & VERIFY (Green)                               │
├─────────────────────────────────────────────────────────────┤
│  • Implement the improvement                                 │
│  • New test PASSES                                           │
│  • All existing tests still pass                             │
└─────────────────────────────────────────────────────────────┘
```

## Types of Improvements

### 1. UX Improvements

Enhance user experience without changing core logic:

```
Examples:
- Settings view scrolls on small screens
- Better loading indicators
- Improved accessibility
- Cleaner visual layout
```

**Test approach**: UI behavior tests or manual verification

### 2. Domain Improvements

Enhance domain model behavior:

```
Examples:
- Add computed property for common queries
- Improve status calculation
- Add convenience methods
- Better encapsulation
```

**Test approach**: State-based domain tests

```swift
@Test func `model provides convenient access to lowest quota`() {
    // Given
    let snapshot = UsageSnapshot(quotas: [quota1, quota2, quota3])

    // Then - new convenience property
    #expect(snapshot.lowestQuota == quota2)
}
```

### 3. Infrastructure Improvements

Enhance probes, storage, or adapters:

```
Examples:
- Better error messages
- More robust parsing
- Improved timeout handling
- Caching support
```

**Test approach**: Behavior tests with mocked dependencies

### 4. Performance Improvements

Optimize existing functionality:

```
Examples:
- Reduce redundant API calls
- Lazy loading
- Parallel execution
- Caching
```

**Test approach**: Behavior tests (same results, better performance)

## TDD Pattern (Chicago School)

### Write Test for Improved Behavior

```swift
@Suite
struct {Component}Tests {

    @Test func `{describes improved behavior}`() {
        // Given - standard setup
        let component = Component(...)

        // When - action
        let result = component.improvedMethod()

        // Then - verify improved behavior
        #expect(result.hasImprovedProperty)
    }
}
```

### Keep Existing Tests

Improvements should NOT break existing behavior:

```bash
# Run all tests to ensure no regressions
swift test
```

## Architecture Reference

> **Full documentation:** [docs/ARCHITECTURE.md](../../../docs/ARCHITECTURE.md)

| Layer | Location | Improvement Examples |
|-------|----------|---------------------|
| **Domain** | `Sources/Domain/` | New computed properties, convenience methods |
| **Infrastructure** | `Sources/Infrastructure/` | Better parsing, error handling |
| **App** | `Sources/App/` | UI enhancements, accessibility |

## Guidelines

### Do

- Keep changes focused and minimal
- Maintain existing behavior
- Add tests for new behavior
- Follow existing code patterns
- Update CHANGELOG

### Don't

- Over-engineer simple improvements
- Change unrelated code
- Break existing tests
- Add features (use implement-feature)
- Skip tests for "small" changes

## Checklist

- [ ] Current behavior understood
- [ ] Improvement scope defined (minimal)
- [ ] Test for improved behavior written
- [ ] Test FAILS before implementation
- [ ] Improvement implemented
- [ ] New test PASSES
- [ ] All existing tests still pass (`swift test`)
- [ ] CHANGELOG updated with improvement