port message to common.js style and add tests

test/message.js

@@ -0,0 +1,28 @@
+var assert = require('assert');
+var Message = require('../').Message;
+var Key = require('../').Key;
+var hexToBytes = require('../').convert.hexToBytes;
+
+var priv = '18e14a7b6a307f426a94f8114701e7c8e774e7f9a47e2c2035db29a206321725';
+var addr = '16UwLL9Risc3QfPqBUvKofHmBQ7wMtjvM';
+var msg = 'foobar';
+
+test('create', function() {
+    var key = Key(hexToBytes(priv));
+    assert.equal(key.getBitcoinAddress().toString(), addr);
+
+    var sig = Message.signMessage(key, msg);
+    assert.ok(Message.verifyMessage(addr, sig, msg));
+    // wrong message
+    assert.ok(!Message.verifyMessage(addr, sig, 'not foobar'));
+    // wrong address
+    assert.ok(!Message.verifyMessage('1MsHWS1BnwMc3tLE8G35UXsS58fKipzB7a', sig, msg));
+});
+
+test('incorrect signature', function() {
+    // wrong signature
+    var priv = '5HwoXVkHoRM8sL2KmNRS217n1g8mPPBomrY7yehCuXC1115WWsh';
+    var key = Key(hexToBytes(priv));
+    var sig = Message.signMessage(key, msg);
+    assert.ok(!Message.verifyMessage(addr, sig, msg));
+});