Add getData functionality to script

lib/script/script.js

@@ -332,6 +332,22 @@ Script.prototype.isDataOut = function() {
         this.chunks[1].length === this.chunks.len));
 };
 
+/**
+ * Retrieve the associated data for this script.
+ * In the case of a pay to public key hash or P2SH, return the hash.
+ * In the case of a standard OP_RETURN, return the data
+ * @returns {Buffer}
+ */
+Script.prototype.getData = function() {
+  if (this.isDataOut() || this.isScriptHashOut()) {
+    return new Buffer(this.chunks[1].buf);
+  }
+  if (this.isPublicKeyHashOut()) {
+    return new Buffer(this.chunks[2].buf);
+  }
+  throw new Error('Unrecognized script type to get data from');
+};
+
 /**
  * @returns true if the script is only composed of data pushing
  * opcodes or small int opcodes (OP_0, OP_1, ..., OP_16)

test/script/script.js

@@ -1,7 +1,10 @@
 'use strict';
 
 var should = require('chai').should();
+var expect = require('chai').expect;
 var bitcore = require('../..');
+
+var BufferUtil = bitcore.util.buffer;
 var Script = bitcore.Script;
 var Opcode = bitcore.Opcode;
 var PublicKey = bitcore.PublicKey;
@@ -566,4 +569,25 @@ describe('Script', function() {
 
   });
 
+  describe('getData returns associated data', function() {
+    it('for a P2PKH address', function() {
+      var address = Address.fromString('1NaTVwXDDUJaXDQajoa9MqHhz4uTxtgK14');
+      var script = Script.buildPublicKeyHashOut(address);
+      expect(BufferUtil.equal(script.getData(), address.hashBuffer)).to.be.true();
+    });
+    it('for a P2SH address', function() {
+      var address = Address.fromString('3GhtMmAbWrUf6Y8vDxn9ETB14R6V7Br3mt');
+      var script = new Script(address);
+      expect(BufferUtil.equal(script.getData(), address.hashBuffer)).to.be.true();
+    });
+    it('for a standard opreturn output', function() {
+      expect(BufferUtil.equal(Script('OP_RETURN 1 0xFF').getData(), new Buffer([255]))).to.be.true();
+    });
+    it('fails if content is not recognized', function() {
+      expect(function() {
+        return Script('1 0xFF').getData();
+      }).to.throw();
+    });
+  });
+
 });