index: avoid BIP39 instantiation

index.js

@@ -4,16 +4,14 @@ var secureRandom = require('secure-random')
 
 var DEFAULT_WORDLIST = require('./wordlists/en.json')
 
-function BIP39(wordlist) {
+function mnemonicToSeed(mnemonic, password) {
-  this.wordlist = wordlist || DEFAULT_WORDLIST
+  var options = { iterations: 2048, hasher: CryptoJS.algo.SHA512, keySize: 512/32 }
-}
-
-BIP39.prototype.mnemonicToSeed = function(mnemonic, password) {
-  var options = {iterations: 2048, hasher: CryptoJS.algo.SHA512, keySize: 512/32}
   return CryptoJS.PBKDF2(mnemonic, salt(password), options).toString(CryptoJS.enc.Hex)
 }
 
-BIP39.prototype.entropyToMnemonic = function(entropy) {
+function entropyToMnemonic(entropy, wordlist) {
+  wordlist = wordlist || DEFAULT_WORDLIST
+
   var entropyBuffer = new Buffer(entropy, 'hex')
   var entropyBits = bytesToBinary([].slice.call(entropyBuffer))
   var checksum = checksumBits(entropyBuffer)
@@ -24,26 +22,27 @@ BIP39.prototype.entropyToMnemonic = function(entropy) {
   var words = chunks.map(function(binary) {
     var index = parseInt(binary, 2)
 
-    return this.wordlist[index]
+    return wordlist[index]
-  }, this)
+  })
 
   return words.join(' ')
 }
 
-BIP39.prototype.generateMnemonic = function(strength, rng) {
+function generateMnemonic(strength, rng, wordlist) {
   strength = strength || 128
   rng = rng || secureRandom.randomBuffer
 
   var hex = rng(strength / 8).toString('hex')
-  return this.entropyToMnemonic(hex)
+  return entropyToMnemonic(hex, wordlist)
 }
 
-BIP39.prototype.validateMnemonic = function(mnemonic) {
+function validateMnemonic(mnemonic, wordlist) {
+  wordlist = wordlist || DEFAULT_WORDLIST
+
   var words = mnemonic.split(' ')
 
   if (words.length % 3 !== 0) return false
 
-  var wordlist = this.wordlist
   var belongToList = words.every(function(word) {
     return wordlist.indexOf(word) > -1
   })
@@ -102,4 +101,9 @@ function lpad(str, padString, length) {
   return str;
 }
 
-module.exports = BIP39
+module.exports = {
+  mnemonicToSeed: mnemonicToSeed,
+  entropyToMnemonic: entropyToMnemonic,
+  generateMnemonic: generateMnemonic,
+  validateMnemonic: validateMnemonic
+}

test/index.js

@@ -9,29 +9,12 @@ var wordlists = {
 var vectors = require('./vectors.json')
 
 describe('BIP39', function() {
-  describe('constructor', function() {
-    it('defaults language to english', function() {
-      var bip39 = new BIP39()
-      assert.deepEqual(bip39.wordlist, wordlists.english)
-    })
-
-    it('accepts a custom wordlist', function() {
-      var bip39 = new BIP39(wordlists.custom)
-      assert.deepEqual(bip39.wordlist, wordlists.custom)
-    })
-  })
-
   describe('mnemonicToSeed', function() {
     this.timeout(20000)
 
-    var bip39
-    beforeEach(function() {
-      bip39 = new BIP39()
-    })
-
     vectors.english.forEach(function(v, i) {
       it('works for tests vector ' + i, function() {
-        assert.equal(bip39.mnemonicToSeed(v[1], 'TREZOR'), v[2])
+        assert.equal(BIP39.mnemonicToSeed(v[1], 'TREZOR'), v[2])
       })
     })
   })
@@ -39,23 +22,20 @@ describe('BIP39', function() {
   describe('entropyToMnemonic', function() {
     vectors.english.forEach(function(v, i) {
       it('works for tests vector ' + i, function() {
-        var bip39 = new BIP39()
+        assert.equal(BIP39.entropyToMnemonic(v[0]), v[1])
-        assert.equal(bip39.entropyToMnemonic(v[0]), v[1])
       })
     })
 
     vectors.custom.forEach(function(v, i) {
       it('works for custom test vector ' + i, function() {
-        var bip39 = new BIP39(wordlists.custom)
+        assert.equal(BIP39.entropyToMnemonic(v[0], wordlists.custom), v[1])
-        assert.equal(bip39.entropyToMnemonic(v[0]), v[1])
       })
     })
   })
 
   describe('generateMnemonic', function() {
     it('generates a mnemonic', function() {
-      var bip39 = new BIP39()
+      var mnemonic = BIP39.generateMnemonic(96)
-      var mnemonic = bip39.generateMnemonic(96)
       var words = mnemonic.split(' ')
 
       assert.equal(words.length, 9)
@@ -67,9 +47,8 @@ describe('BIP39', function() {
         buffer.fill(4) // guaranteed random
         return buffer
       }
-      var bip39 = new BIP39()
 
-      var mnemonic = bip39.generateMnemonic(64, rng)
+      var mnemonic = BIP39.generateMnemonic(64, rng)
       assert.equal(mnemonic, 'advice cage absurd amount doctor act')
     })
 
@@ -80,45 +59,39 @@ describe('BIP39', function() {
         return buffer
       }
 
-      var bip39 = new BIP39(wordlists.custom)
+      var mnemonic = BIP39.generateMnemonic(64, rng, wordlists.custom)
-      var mnemonic = bip39.generateMnemonic(64, rng)
       assert.equal(mnemonic, 'adv1c3 cag3 ab5urd am0unt d0ct0r act')
     })
   })
 
   describe('validateMnemonic', function() {
     vectors.english.forEach(function(v, i) {
-      var bip39 = new BIP39()
 
       it('passes check ' + i, function() {
-        assert(bip39.validateMnemonic(v[1]))
+        assert(BIP39.validateMnemonic(v[1]))
       })
     })
 
     describe('with a custom wordlist', function() {
       vectors.custom.forEach(function(v, i) {
-        var bip39 = new BIP39(wordlists.custom)
 
         it('passes custom check ' + i, function() {
-          assert(bip39.validateMnemonic(v[1]))
+          assert(BIP39.validateMnemonic(v[1], wordlists.custom))
         })
       })
     })
 
     it('fails for mnemonics of wrong length', function() {
-      var bip39 = new BIP39()
+      assert(!BIP39.validateMnemonic('sleep kitten'))
-      assert(!bip39.validateMnemonic('sleep kitten'))
+      assert(!BIP39.validateMnemonic('sleep kitten sleep kitten sleep kitten'))
-      assert(!bip39.validateMnemonic('sleep kitten sleep kitten sleep kitten'))
     })
 
     it('fails for mnemonics that contains words not from the word list', function() {
-      var bip39 = new BIP39()
+      assert(!BIP39.validateMnemonic("turtle front uncle idea crush write shrug there lottery flower risky shell"))
-      assert(!bip39.validateMnemonic("turtle front uncle idea crush write shrug there lottery flower risky shell"))
     })
 
     it('fails for mnemonics of invalid checksum', function() {
-      var bip39 = new BIP39()
+      assert(!BIP39.validateMnemonic('sleep kitten sleep kitten sleep kitten sleep kitten sleep kitten sleep kitten'))
-      assert(!bip39.validateMnemonic('sleep kitten sleep kitten sleep kitten sleep kitten sleep kitten sleep kitten'))
     })
   })
 })