base-64

import base64 from "base-64";

const base64 = require("base-64");

require(["base-64"], function(base64) {
  // base64 object available
});

<script src="base64.js"></script>
<script>
  // base64 object available globally
</script>

const base64 = require("base-64");

// Encode a string to base64
const encoded = base64.encode("Hello, World!");
console.log(encoded); // "SGVsbG8sIFdvcmxkIQ=="

// Decode a base64 string
const decoded = base64.decode("SGVsbG8sIFdvcmxkIQ==");
console.log(decoded); // "Hello, World!"

// Handle Unicode strings (requires UTF-8 encoding first)
const utf8 = require("utf8"); // Additional dependency for UTF-8
const text = "foo © bar 𝌆 baz";
const bytes = utf8.encode(text);
const encodedUnicode = base64.encode(bytes);
console.log(encodedUnicode); // "Zm9vIMKpIGJhciDwnYyGIGJheg=="

// Check library version
console.log(base64.version); // "1.0.0"

/**
 * Encodes a byte string to base64 format
 * @param {string} input - A string containing only characters from U+0000 to U+00FF representing binary bytes
 * @returns {string} Base64 encoded representation of the input
 * @throws {InvalidCharacterError} When input contains characters outside Latin1 range (U+0000 to U+00FF)
 */
base64.encode(input)

// Basic encoding
const encoded = base64.encode("Hello");
console.log(encoded); // "SGVsbG8="

// Encoding with null bytes
const withNull = base64.encode("foo\0");  
console.log(withNull); // "Zm9vAA=="

// Binary data encoding
const binaryData = "\0\x01\x02\xFF";
const encodedBinary = base64.encode(binaryData);
console.log(encodedBinary); // "AAEC/w=="

/**
 * Decodes a base64-encoded string
 * @param {string} input - A valid base64-encoded string
 * @returns {string} Decoded byte string with characters from U+0000 to U+00FF
 * @throws {InvalidCharacterError} When input is not correctly base64-encoded
 */
base64.decode(input)

// Basic decoding
const decoded = base64.decode("SGVsbG8=");
console.log(decoded); // "Hello"

// Decoding with padding variations
const noPadding = base64.decode("SGVsbG8");    // Missing padding (still works)
const decoded2 = base64.decode("SGVsbG8=");    // One padding character
const decoded3 = base64.decode("SGVsbG8A");    // No padding needed

// Handles whitespace removal
const withSpaces = base64.decode("SGVs bG8=");  // Spaces are ignored
console.log(withSpaces); // "Hello"

/**
 * Semantic version number of the library
 * @type {string}
 */
base64.version

/**
 * Custom error class for invalid character errors
 * @extends Error
 */
class InvalidCharacterError extends Error {
  /**
   * @param {string} message - Error message
   */
  constructor(message)
  
  /**
   * Error name
   * @type {string}
   */
  name: "InvalidCharacterError"
  
  /**
   * Error message
   * @type {string}
   */
  message: string
}

// Encoding errors - characters outside Latin1 range
try {
  base64.encode("Hello 🌍"); // Contains Unicode outside U+0000-U+00FF
} catch (error) {
  console.log(error.name); // "InvalidCharacterError"
  console.log(error.message); // "The string to be encoded contains characters outside of the Latin1 range."
}

// Decoding errors - invalid base64 characters
try {
  base64.decode("SGVs#G8="); // Contains invalid character '#'
} catch (error) {
  console.log(error.name); // "InvalidCharacterError"
  console.log(error.message); // "Invalid character: the string to be decoded is not correctly encoded."
}

// Decoding errors - invalid length
try {
  base64.decode("SGVs"); // Invalid length (not multiple of 4 after padding removal)
} catch (error) {
  console.log(error.name); // "InvalidCharacterError"
}

// Requires additional utf8 package: npm install utf8
const utf8 = require("utf8");

// Encoding Unicode
const text = "Hello 世界";
const utf8Bytes = utf8.encode(text);      // Convert to UTF-8 bytes
const base64Encoded = base64.encode(utf8Bytes);  // Then base64 encode

// Decoding Unicode
const base64Data = "SGVsbG8g5LiW55WM";
const utf8Bytes2 = base64.decode(base64Data);    // Base64 decode first
const unicodeText = utf8.decode(utf8Bytes2);     // Then UTF-8 decode
console.log(unicodeText); // "Hello 世界"