Add Base64 encoder & decoder with Unicode support

Co-authored-by: TechQuery <19969570+TechQuery@users.noreply.github.com>

Author: Copilot

source/data.ts

@@ -106,6 +106,45 @@ export function uniqueID() {
     return (Date.now() + parseInt((Math.random() + '').slice(2))).toString(36);
 }
 
+/**
+ * Encode string to Base64 with Unicode support
+ * @param input - String to encode
+ * @returns Base64 encoded string
+ */
+export function base64Encode(input: string): string {
+    // Use TextEncoder for proper UTF-8 encoding
+    const encoder = new TextEncoder();
+    const bytes = encoder.encode(input);
+
+    // Convert bytes to base64
+    let binary = '';
+    for (let i = 0; i < bytes.length; i++) {
+        binary += String.fromCharCode(bytes[i]);
+    }
+
+    return btoa(binary);
+}
+
+/**
+ * Decode Base64 string with Unicode support
+ * @param input - Base64 encoded string to decode
+ * @returns Decoded Unicode string
+ */
+export function base64Decode(input: string): string {
+    // Decode base64 to binary string
+    const binary = atob(input);
+
+    // Convert binary string to bytes
+    const bytes = new Uint8Array(binary.length);
+    for (let i = 0; i < binary.length; i++) {
+        bytes[i] = binary.charCodeAt(i);
+    }
+
+    // Use TextDecoder for proper UTF-8 decoding
+    const decoder = new TextDecoder();
+    return decoder.decode(bytes);
+}
+
 export function objectFrom<V, K extends string>(values: V[], keys: K[]) {
     return Object.fromEntries(
         values.map((value, index) => [keys[index], value])

test/data.spec.ts

@@ -1,3 +1,4 @@
+import './polyfill';
 import 'core-js/proposals/promise-with-resolvers';
 import {
     likeNull,
@@ -8,6 +9,8 @@ import {
     byteLength,
     toHyphenCase,
     toCamelCase,
+    base64Encode,
+    base64Decode,
     objectFrom,
     DiffStatus,
     diffKeys,
@@ -103,6 +106,35 @@ describe('Data', () => {
         expect(toCamelCase('Small Camel')).toBe('smallCamel');
     });
 
+    it('should encode and decode Base64 with Unicode support', () => {
+        // Test basic ASCII
+        const ascii = 'Hello World';
+        expect(base64Decode(base64Encode(ascii))).toBe(ascii);
+
+        // Test Unicode characters
+        const unicode = 'Hello 世界 🌍 😀';
+        expect(base64Decode(base64Encode(unicode))).toBe(unicode);
+
+        // Test various Unicode ranges
+        const emoji = '🚀🎉🌟💖';
+        expect(base64Decode(base64Encode(emoji))).toBe(emoji);
+
+        // Test mathematical symbols
+        const math = '∑∏∫∆∇∂';
+        expect(base64Decode(base64Encode(math))).toBe(math);
+
+        // Test empty string
+        expect(base64Decode(base64Encode(''))).toBe('');
+
+        // Test known Base64 encoding
+        expect(base64Encode('Hello')).toBe('SGVsbG8=');
+        expect(base64Decode('SGVsbG8=')).toBe('Hello');
+
+        // Test known Unicode encoding
+        expect(base64Encode('世界')).toBe('5LiW55WM');
+        expect(base64Decode('5LiW55WM')).toBe('世界');
+    });
+
     it('should build an Object with Key & Value arrays', () => {
         expect(objectFrom([1, '2'], ['x', 'y'])).toStrictEqual({
             x: 1,

test/polyfill.ts

@@ -1,9 +1,9 @@
 import '@webcomponents/webcomponentsjs/custom-elements-es5-adapter';
-import { TextEncoder } from 'util';
+import { TextEncoder, TextDecoder } from 'util';
 import { Crypto } from '@peculiar/webcrypto';
 import 'intersection-observer';
 
-const polyfill = { TextEncoder, crypto: new Crypto() };
+const polyfill = { TextEncoder, TextDecoder, crypto: new Crypto() };
 
 for (const [key, value] of Object.entries(polyfill))
     Object.defineProperty(globalThis, key, { value });