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

// 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

// 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

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

pub struct AlertTitleProps {
    // Styling
    pub class: Option<String>,                   // Custom CSS classes
    
    // Children
    pub children: Children,                      // Title content
}

AlertDescription Props

pub struct AlertDescriptionProps {
    // Styling
    pub class: Option<String>,                   // Custom CSS classes
    
    // Children
    pub children: Children,                      // Description content
}

---

🎨 Visual Design

Variants

pub enum AlertVariant {
    Default,    // Standard alert
    Destructive, // Error/danger alert
    Warning,    // Warning alert
    Success,    // Success alert
    Info,       // Information alert
}

Sizes

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