leptos-shadcn-ui/docs/remediation/components/alert/DESIGN.md

# 🎯 Alert Component Design
**Senior Rust Staff Engineer Review - September 20, 2025**

## 📋 Component Overview

The **Alert** component provides contextual feedback messages to users. It displays important information, warnings, errors, or success messages with appropriate styling and icons.

### **Current Status**
- **File Size**: 106 lines (default.rs) - ✅ **COMPLIANT**
- **Test Coverage**: 3 test files - ✅ **MODERATE**
- **Priority**: **P2** - Medium Priority

---

## 🎨 Design Principles

### **1. Accessibility First**
- **ARIA Support**: Full ARIA attributes for screen readers
- **Color Contrast**: Meets WCAG 2.1 AA standards
- **Screen Reader Support**: Proper announcements for alerts
- **Focus Management**: Clear focus indicators

### **2. Performance Optimized**
- **Lightweight**: Minimal bundle impact
- **Memory Management**: Proper cleanup of resources
- **Signal Management**: Efficient reactive state updates
- **Bundle Size**: Minimal impact on application bundle

### **3. Developer Experience**
- **Type Safety**: Full TypeScript support with proper prop types
- **Composable**: Easy to extend and customize
- **Consistent API**: Follows established patterns
- **Documentation**: Comprehensive examples and guides

---

## 🏗️ Architecture

### **Core Components**
```rust
// Main alert container
pub struct Alert {
    pub variant: AlertVariant,
    pub size: AlertSize,
    pub dismissible: bool,
    pub on_dismiss: Option<Callback<()>>,
    pub class: Option<String>,
    pub children: Children,
}

// Alert title
pub struct AlertTitle {
    pub class: Option<String>,
    pub children: Children,
}

// Alert description
pub struct AlertDescription {
    pub class: Option<String>,
    pub children: Children,
}
```

### **State Management**
```rust
// Alert state
pub struct AlertState {
    pub is_visible: RwSignal<bool>,
    pub is_dismissed: RwSignal<bool>,
    pub animation_state: RwSignal<AnimationState>,
}

// Animation state
pub enum AnimationState {
    Entering,
    Visible,
    Exiting,
    Hidden,
}
```

---

## 🎯 API Design

### **Alert Props**
```rust
pub struct AlertProps {
    // Core functionality
    pub variant: AlertVariant,                   // Alert type
    pub size: AlertSize,                         // Alert size
    pub dismissible: bool,                       // Can be dismissed
    pub on_dismiss: Option<Callback<()>>,        // Dismiss callback
    
    // Styling
    pub class: Option<String>,                   // Custom CSS classes
    
    // Accessibility
    pub aria_label: Option<String>,              // ARIA label
    pub role: Option<String>,                    // ARIA role
    
    // Children
    pub children: Children,                      // Alert content
}
```

### **AlertTitle Props**
```rust
pub struct AlertTitleProps {
    // Styling
    pub class: Option<String>,                   // Custom CSS classes
    
    // Children
    pub children: Children,                      // Title content
}
```

### **AlertDescription Props**
```rust
pub struct AlertDescriptionProps {
    // Styling
    pub class: Option<String>,                   // Custom CSS classes
    
    // Children
    pub children: Children,                      // Description content
}
```

---

## 🎨 Visual Design

### **Variants**
```rust
pub enum AlertVariant {
    Default,    // Standard alert
    Destructive, // Error/danger alert
    Warning,    // Warning alert
    Success,    // Success alert
    Info,       // Information alert
}
```

### **Sizes**
```rust
pub enum AlertSize {
    Small,      // Compact alert
    Medium,     // Standard alert
    Large,      // Large alert
}
```

### **States**
- **Visible**: Alert is shown
- **Dismissed**: Alert is hidden
- **Animating**: Transition state
- **Focused**: Keyboard focus state

---

## 🧪 Testing Strategy

### **Unit Tests**
- [ ] **Basic Rendering**: Component renders without errors
- [ ] **Props Handling**: All props are properly applied
- [ ] **Variant Styling**: Different variants render correctly
- [ ] **Size Styling**: Different sizes render correctly
- [ ] **Dismissible**: Dismiss functionality works

### **Integration Tests**
- [ ] **Multiple Alerts**: Multiple alerts work together
- [ ] **Dismiss Behavior**: on_dismiss callback fires
- [ ] **Animation States**: Transitions work correctly
- [ ] **Keyboard Navigation**: Tab navigation works
- [ ] **Focus Management**: Focus moves correctly

### **Accessibility Tests**
- [ ] **Screen Reader**: Content is announced correctly
- [ ] **Color Contrast**: Meets WCAG 2.1 AA standards
- [ ] **ARIA Attributes**: Proper ARIA implementation
- [ ] **Focus Indicators**: Focus is clearly visible

### **Performance Tests**
- [ ] **Rendering Performance**: Fast initial render
- [ ] **Memory Usage**: No memory leaks
- [ ] **Bundle Size**: Minimal impact on bundle
- [ ] **Signal Updates**: Efficient reactive updates

---

## 🚀 Implementation Plan

### **Phase 1: Core Implementation (Week 1)**
- [ ] **Basic Structure**: Create core component files
- [ ] **Props Definition**: Define all prop types
- [ ] **State Management**: Implement reactive state
- [ ] **Basic Rendering**: Simple alert functionality

### **Phase 2: Advanced Features (Week 2)**
- [ ] **Variants**: Implement all alert variants
- [ ] **Sizes**: Implement all alert sizes
- [ ] **Dismissible**: Dismiss functionality
- [ ] **Animations**: Enter/exit animations

### **Phase 3: Testing & Documentation (Week 3)**
- [ ] **Unit Tests**: Comprehensive test coverage
- [ ] **Integration Tests**: Multi-alert scenarios
- [ ] **Accessibility Tests**: Screen reader and keyboard
- [ ] **Documentation**: Examples and guides

### **Phase 4: Optimization (Week 4)**
- [ ] **Performance**: Optimize rendering and memory
- [ ] **Bundle Size**: Minimize impact on bundle
- [ ] **Signal Management**: Efficient reactive updates
- [ ] **Final Testing**: End-to-end validation

---

## 📊 Success Metrics

### **Functionality**
- [ ] **Basic Alert**: Alert displays correctly
- [ ] **Variants**: All variants render properly
- [ ] **Sizes**: All sizes render properly
- [ ] **Dismissible**: Dismiss functionality works

### **Accessibility**
- [ ] **Screen Reader**: Content is announced correctly
- [ ] **Color Contrast**: Meets WCAG 2.1 AA standards
- [ ] **ARIA Compliance**: Meets WCAG 2.1 AA standards
- [ ] **Focus Management**: Focus moves correctly

### **Performance**
- [ ] **Rendering**: Fast initial render (< 16ms)
- [ ] **Memory**: No memory leaks
- [ ] **Bundle Size**: Minimal impact (< 3KB)
- [ ] **Updates**: Efficient reactive updates

### **Developer Experience**
- [ ] **Type Safety**: Full TypeScript support
- [ ] **Documentation**: Comprehensive examples
- [ ] **API Consistency**: Follows established patterns
- [ ] **Error Handling**: Clear error messages

---

## 🎯 Conclusion

The **Alert** component is a **medium priority** component that requires **moderate test coverage improvements**. The component follows **accessibility-first design principles** with **comprehensive screen reader support** and **proper color contrast**.

**Key Focus Areas:**
1. **Test Coverage**: Expand from 3 to 5+ test files
2. **File Size**: Ensure all files under 300 lines
3. **Accessibility**: Comprehensive ARIA support
4. **Performance**: Optimize rendering and memory usage

**Expected Outcome:**
A **production-ready, fully-accessible, well-tested** alert component that meets enterprise standards.

---

*Alert Component Design created: September 20, 2025*  
*Next review: October 20, 2025*