[Bug] Incorrect implementation for base58btc about js-multibase

[beenotung]

also some character(s) are not identified, see examples below:

> require('multibase').encode('base58btc','/').toString()
'zundefined'
> require('multibase').encode('base58btc','1/').toString()
'zundefined'
> require('multibase').encode('base58btc','/1').toString()
'zB'

[beenotung]

It seems the base58btc do not handle string properly

console.log(multibase.encode("base64", 'hello').toString());
// maGVsbG8
console.log(multibase.encode("base64", new Buffer('hello')).toString());
// maGVsbG8

console.log(multibase.encode("base58btc", 'hello').toString());
// zundefined
console.log(multibase.encode("base58btc", new Buffer('hello')).toString());
// zCn8eVZg

[beenotung]

The bug is coming from base-x.

When source is string, e.g. 'y0': carry (source[i]) + digits[j] becomes a string.
So it seems baseX created in constants.js do not support string encoding natively, so I suggest to warp that to support string encoding.

Work in progress thread: #43

Below is the code of encode base-x for understanding:

function encode(source) {
    if (source.length === 0) return ''

    var digits = [0]
    for (var i = 0; i < source.length; ++i) {
      // when source is string, e.g. 'y0': carry (source[i]) + digits[j] becomes a string
      for (var j = 0, carry = source[i]; j < digits.length; ++j) {
        carry += digits[j] << 8
        digits[j] = carry % BASE
        carry = (carry / BASE) | 0
      }

      while (carry > 0) {
        digits.push(carry % BASE)
        carry = (carry / BASE) | 0
      }
    }

    var string = ''

    // deal with leading zeros
    for (var k = 0; source[k] === 0 && k < source.length - 1; ++k) string += LEADER
    // convert digits to a string
    for (var q = digits.length - 1; q >= 0; --q) {
      string += ALPHABET[digits[q]]
    }
    if (string === 'undefined') {
      process.exit(1)
    }

    return string
  }

[beenotung]

Fixed in #43
@olizilla May you help to get it merged?

[hugomrdias]

encode only supports Buffer https://github.com/multiformats/js-multibase#multibaseencode---encodes-a-buffer-into-one-of-the-supported-encodings-prefixing-it-with-the-multibase-code