improve bip32 interface slightly

lib/bip32.js

@@ -17,7 +17,10 @@ var BIP32 = function(str) {
     this.fromString(str);
 }
 
-BIP32.prototype.fromRandom = function() {
+BIP32.prototype.fromRandom = function(network) {
+  if (!network)
+    network = 'mainnet';
+  this.version = constants[network].bip32privkey;
   this.depth = 0x00;
   this.parentFingerprint = new Buffer([0, 0, 0, 0]);
   this.childIndex = new Buffer([0, 0, 0, 0]);

test/test.bip32.js

@@ -36,13 +36,8 @@ describe('BIP32', function() {
     should.exist(BIP32);
   });
 
-  it('should create a mainnet bip32', function() {
-    var bip32 = new BIP32('mainnet');
-    should.exist(bip32);
-  });
-
-  it('should create a testnet bip32', function() {
-    var bip32 = new BIP32('testnet');
+  it('should create a bip32', function() {
+    var bip32 = new BIP32();
     should.exist(bip32);
   });
 
@@ -291,13 +286,15 @@ describe('BIP32', function() {
 
   describe('testnet', function() {
     it('should initialize a new BIP32 correctly from a random BIP32', function() {
-      var b1 = new BIP32('testnet');
+      var b1 = new BIP32();
+      b1.fromRandom('testnet');
       var b2 = new BIP32(b1.extendedPublicKeyString());
       b2.extendedPublicKeyString().should.equal(b1.extendedPublicKeyString());
     });
 
     it('should generate valid ext pub key for testnet', function() {
-      var b = new BIP32('testnet');
+      var b = new BIP32();
+      b.fromRandom('testnet');
       b.extendedPublicKeyString().substring(0,4).should.equal('tpub');
     });
   });