Initial commit: Portfolio Website

Vollständige Next.js 15 Portfolio-Website mit:
- Blog-System mit 100+ Artikeln
- Supabase-Integration
- Responsive Design mit Tailwind CSS
- TypeScript-Konfiguration
- Testing-Setup mit Vitest und Playwright

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/hooks/useLocalStorage.ts

@@ -0,0 +1,99 @@
+import { useState, useEffect, useCallback } from 'react';
+import { handleError } from '../utils/errorHandling';
+
+/**
+ * Function type for updating the stored value
+ * @template T - The type of the stored value
+ * @param value - Either a new value of type T or an updater function that takes the current value and returns a new value
+ */
+type SetValue<T> = (value: T | ((val: T) => T)) => void;
+
+/**
+ * Custom hook for managing state in localStorage with automatic serialization
+ *
+ * @template T - The type of the stored value
+ * @param {string} key - The localStorage key to use
+ * @param {T | (() => T)} initialValue - The initial value or a function that returns the initial value
+ * @returns {[T, SetValue<T>, () => void]} A tuple containing:
+ *   - The current stored value
+ *   - A function to update the stored value
+ *   - A function to remove the value from storage
+ *
+ * @example
+ * ```tsx
+ * const [theme, setTheme, removeTheme] = useLocalStorage('theme', 'light');
+ * setTheme('dark'); // Updates both state and localStorage
+ * removeTheme(); // Removes from localStorage and resets to initial value
+ * ```
+ *
+ * @remarks
+ * - SSR-safe: Returns initial value during server-side rendering
+ * - Automatically serializes/deserializes JSON
+ * - Handles localStorage quota exceeded errors
+ * - Handles invalid JSON gracefully
+ */
+export function useLocalStorage<T>(
+  key: string,
+  initialValue: T | (() => T)
+): [T, SetValue<T>, () => void] {
+  // Get initial value - SSR safe
+  const getInitialValue = useCallback((): T => {
+    // Check if we're in a browser environment
+    if (typeof window === 'undefined') {
+      return initialValue instanceof Function ? initialValue() : initialValue;
+    }
+
+    try {
+      const item = window.localStorage.getItem(key);
+      if (item) {
+        return JSON.parse(item) as T;
+      }
+    } catch (error) {
+      handleError(error, `LocalStorage Read (key: ${key})`);
+    }
+
+    return initialValue instanceof Function ? initialValue() : initialValue;
+  }, [key, initialValue]);
+
+  const [storedValue, setStoredValue] = useState<T>(getInitialValue);
+
+  // Update localStorage whenever storedValue changes
+  useEffect(() => {
+    if (typeof window === 'undefined') {
+      return;
+    }
+
+    try {
+      window.localStorage.setItem(key, JSON.stringify(storedValue));
+    } catch (error) {
+      handleError(error, `LocalStorage Write (key: ${key})`);
+    }
+  }, [key, storedValue]);
+
+  // Set value function that supports both direct values and updater functions
+  const setValue: SetValue<T> = useCallback((value) => {
+    try {
+      setStoredValue((prevValue) => {
+        const newValue = value instanceof Function ? value(prevValue) : value;
+        return newValue;
+      });
+    } catch (error) {
+      handleError(error, `LocalStorage Update (key: ${key})`);
+    }
+  }, [key]);
+
+  // Remove value from localStorage and reset to initial value
+  const removeValue = useCallback(() => {
+    try {
+      if (typeof window !== 'undefined') {
+        window.localStorage.removeItem(key);
+      }
+      const resetValue = initialValue instanceof Function ? initialValue() : initialValue;
+      setStoredValue(resetValue);
+    } catch (error) {
+      handleError(error, `LocalStorage Remove (key: ${key})`);
+    }
+  }, [key, initialValue]);
+
+  return [storedValue, setValue, removeValue];
+}