add tests

apps/website/lib/display-objects/HealthAlertDisplay.ts

@@ -0,0 +1,53 @@
+/**
+ * Health Alert Display Object
+ *
+ * Provides formatting and display logic for health alerts.
+ * This display object isolates UI-specific formatting from business logic.
+ */
+
+export class HealthAlertDisplay {
+  static formatSeverity(type: 'critical' | 'warning' | 'info'): string {
+    const severities: Record<string, string> = {
+      critical: 'Critical',
+      warning: 'Warning',
+      info: 'Info',
+    };
+    return severities[type] || 'Info';
+  }
+
+  static formatSeverityColor(type: 'critical' | 'warning' | 'info'): string {
+    const colors: Record<string, string> = {
+      critical: '#ef4444', // red-500
+      warning: '#f59e0b', // amber-500
+      info: '#3b82f6', // blue-500
+    };
+    return colors[type] || '#3b82f6';
+  }
+
+  static formatTimestamp(timestamp: string): string {
+    const date = new Date(timestamp);
+    return date.toLocaleString('en-US', {
+      year: 'numeric',
+      month: 'short',
+      day: 'numeric',
+      hour: '2-digit',
+      minute: '2-digit',
+      second: '2-digit',
+    });
+  }
+
+  static formatRelativeTime(timestamp: string): string {
+    const now = new Date();
+    const date = new Date(timestamp);
+    const diffMs = now.getTime() - date.getTime();
+    const diffMins = Math.floor(diffMs / 60000);
+    const diffHours = Math.floor(diffMs / 3600000);
+    const diffDays = Math.floor(diffMs / 86400000);
+
+    if (diffMins < 1) return 'Just now';
+    if (diffMins < 60) return `${diffMins}m ago`;
+    if (diffHours < 24) return `${diffHours}h ago`;
+    if (diffDays < 7) return `${diffDays}d ago`;
+    return `${Math.floor(diffDays / 7)}w ago`;
+  }
+}