store accounts in closure instead of on object

src/wallet.js

@@ -19,6 +19,9 @@ var Wallet = function (seed, options) {
     // Stored in a closure to make accidental serialization less likely
     var masterkey = null;
     var me = this;
+    var accountZero = null;
+    var internalAccount = null;
+    var externalAccount = null;
 
     // Addresses
     this.addresses = [];
@@ -39,18 +42,18 @@ var Wallet = function (seed, options) {
 
     // HD first-level child derivation method should be private
     // See https://bitcointalk.org/index.php?topic=405179.msg4415254#msg4415254
-    this.accountZero = masterkey.derivePrivate(0)
-    this.externalAccount = this.accountZero.derive(0)
-    this.internalAccount = this.accountZero.derive(1)
+    accountZero = masterkey.derivePrivate(0)
+    externalAccount = accountZero.derive(0)
+    internalAccount = accountZero.derive(1)
 
     this.generateAddress = function() {
-        var key = this.externalAccount.derive(this.addresses.length)
+        var key = externalAccount.derive(this.addresses.length)
         this.addresses.push(key.getBitcoinAddress().toString())
         return this.addresses[this.addresses.length - 1]
     }
 
     this.generateChangeAddress = function() {
-        var key = this.internalAccount.derive(this.changeAddresses.length)
+        var key = internalAccount.derive(this.changeAddresses.length)
         this.changeAddresses.push(key.getBitcoinAddress().toString())
         return this.changeAddresses[this.changeAddresses.length - 1]
     }
@@ -174,13 +177,16 @@ var Wallet = function (seed, options) {
     }
 
     this.getMasterKey = function() { return masterkey }
+    this.getAccountZero = function() { return accountZero }
+    this.getInternalAccount = function() { return internalAccount }
+    this.getExternalAccount = function() { return externalAccount }
 
     this.getPrivateKey = function(index) {
-        return this.externalAccount.derive(index).priv
+        return externalAccount.derive(index).priv
     }
 
     this.getInternalPrivateKey = function(index) {
-        return this.internalAccount.derive(index).priv
+        return internalAccount.derive(index).priv
     }
 
     this.getPrivateKeyForAddress = function(address) {

test/wallet.js

@@ -22,19 +22,19 @@ describe('Wallet', function() {
     })
 
     it("generates m/0' as the main account", function() {
-      var mainAccount = wallet.accountZero
+      var mainAccount = wallet.getAccountZero()
       assert.equal(mainAccount.index, 0 + HDNode.HIGHEST_BIT)
       assert.equal(mainAccount.depth, 1)
     })
 
     it("generates m/0'/0 as the external account", function() {
-      var account = wallet.externalAccount
+      var account = wallet.getExternalAccount()
       assert.equal(account.index, 0)
       assert.equal(account.depth, 2)
     })
 
     it("generates m/0'/1 as the internal account", function() {
-      var account = wallet.internalAccount
+      var account = wallet.getInternalAccount()
       assert.equal(account.index, 1)
       assert.equal(account.depth, 2)
     })
@@ -79,8 +79,8 @@ describe('Wallet', function() {
     it('returns the private key at the given index of external account', function(){
       var wallet = new Wallet(seed, {network: 'testnet'})
 
-      assertPrivateKeyEqual(wallet.getPrivateKey(0), wallet.externalAccount.derive(0).priv)
-      assertPrivateKeyEqual(wallet.getPrivateKey(1), wallet.externalAccount.derive(1).priv)
+      assertPrivateKeyEqual(wallet.getPrivateKey(0), wallet.getExternalAccount().derive(0).priv)
+      assertPrivateKeyEqual(wallet.getPrivateKey(1), wallet.getExternalAccount().derive(1).priv)
     })
   })
 
@@ -88,8 +88,8 @@ describe('Wallet', function() {
     it('returns the private key at the given index of internal account', function(){
       var wallet = new Wallet(seed, {network: 'testnet'})
 
-      assertPrivateKeyEqual(wallet.getInternalPrivateKey(0), wallet.internalAccount.derive(0).priv)
-      assertPrivateKeyEqual(wallet.getInternalPrivateKey(1), wallet.internalAccount.derive(1).priv)
+      assertPrivateKeyEqual(wallet.getInternalPrivateKey(0), wallet.getInternalAccount().derive(0).priv)
+      assertPrivateKeyEqual(wallet.getInternalPrivateKey(1), wallet.getInternalAccount().derive(1).priv)
     })
   })
 
@@ -101,9 +101,9 @@ describe('Wallet', function() {
       wallet.generateAddress()
 
       assertPrivateKeyEqual(wallet.getPrivateKeyForAddress("n2fiWrHqD6GM5GiEqkbWAc6aaZQp3ba93X"),
-                   wallet.externalAccount.derive(1).priv)
+                   wallet.getExternalAccount().derive(1).priv)
       assertPrivateKeyEqual(wallet.getPrivateKeyForAddress("mnXiDR4MKsFxcKJEZjx4353oXvo55iuptn"),
-                   wallet.internalAccount.derive(0).priv)
+                   wallet.getInternalAccount().derive(0).priv)
     })
 
     it('raises an error when address is not found', function(){