Script().fromBuffer(buf)

...code heavily inspired/copied from bitcore

lib/script.js

@@ -8,7 +8,11 @@ var Script = function Script(buf) {
   this.chunks = [];
 
   if (Buffer.isBuffer(buf)) {
-    this.parse(buf);
+    this.fromBuffer(buf);
+  }
+  else if (typeof buf === 'string') {
+    var str = buf;
+    this.fromString(str);
   }
   else if (typeof buf !== 'undefined') {
     var obj = buf;
@@ -21,4 +25,35 @@ Script.prototype.set = function(obj) {
   return this;
 };
 
+Script.prototype.fromBuffer = function(buf) {
+  this.chunks = [];
+
+  var br = new BufferReader(buf);
+  while (!br.eof()) {
+    var opcode = br.readUInt8();
+
+    var len, chunk;
+    if (opcode > 0 && opcode < Opcode.map.OP_PUSHDATA1) {
+      // Read some bytes of data, opcode value is the length of data
+      this.chunks.push(br.buffer(opcode));
+    } else if (opcode === Opcode.map.OP_PUSHDATA1) {
+      len = br.readUInt8();
+      chunk = br.buffer(len);
+      this.chunks.push(chunk);
+    } else if (opcode === Opcode.map.OP_PUSHDATA2) {
+      len = br.readUInt16LE();
+      chunk = br.buffer(len);
+      this.chunks.push(chunk);
+    } else if (opcode === Opcode.map.OP_PUSHDATA4) {
+      len = br.readUInt32LE();
+      chunk = br.buffer(len);
+      this.chunks.push(chunk);
+    } else {
+      this.chunks.push(opcode);
+    }
+  }
+
+  return this;
+};
+
 module.exports = Script;

test/script.js

@@ -1,6 +1,8 @@
 var Script = require('../lib/script');
 var should = require('chai').should();
 var Opcode = require('../lib/opcode');
+var BufferReader = require('../lib/bufferreader');
+var BufferWriter = require('../lib/bufferwriter');
 
 describe('Script', function() {
   
@@ -8,4 +10,58 @@ describe('Script', function() {
     var script = new Script();
   });
 
+  describe('#fromBuffer', function() {
+    
+    it('should parse this buffer containing an OP code', function() {
+      var buf = new Buffer(1);
+      buf[0] = Opcode('OP_0').toNumber();
+      var script = Script().fromBuffer(buf);
+      script.chunks.length.should.equal(1);
+      script.chunks[0].should.equal(buf[0]);
+    });
+
+    it('should parse this buffer containing another OP code', function() {
+      var buf = new Buffer(1);
+      buf[0] = Opcode('OP_CHECKMULTISIG').toNumber();
+      var script = Script().fromBuffer(buf);
+      script.chunks.length.should.equal(1);
+      script.chunks[0].should.equal(buf[0]);
+    });
+
+    it('should parse this buffer containing three bytes of data', function() {
+      var buf = new Buffer([3, 1, 2, 3]);
+      var script = Script().fromBuffer(buf);
+      script.chunks.length.should.equal(1);
+      script.chunks[0].toString('hex').should.equal('010203');
+    });
+
+    it('should parse this buffer containing OP_PUSHDATA1 and three bytes of data', function() {
+      var buf = new Buffer([0, 0, 1, 2, 3]);
+      buf[0] = Opcode('OP_PUSHDATA1').toNumber();
+      buf.writeUInt8(3, 1);
+      var script = Script().fromBuffer(buf);
+      script.chunks.length.should.equal(1);
+      script.chunks[0].toString('hex').should.equal('010203');
+    });
+
+    it('should parse this buffer containing OP_PUSHDATA2 and three bytes of data', function() {
+      var buf = new Buffer([0, 0, 0, 1, 2, 3]);
+      buf[0] = Opcode('OP_PUSHDATA2').toNumber();
+      buf.writeUInt16LE(3, 1);
+      var script = Script().fromBuffer(buf);
+      script.chunks.length.should.equal(1);
+      script.chunks[0].toString('hex').should.equal('010203');
+    });
+
+    it('should parse this buffer containing OP_PUSHDATA4 and three bytes of data', function() {
+      var buf = new Buffer([0, 0, 0, 0, 0, 1, 2, 3]);
+      buf[0] = Opcode('OP_PUSHDATA4').toNumber();
+      buf.writeUInt16LE(3, 1);
+      var script = Script().fromBuffer(buf);
+      script.chunks.length.should.equal(1);
+      script.chunks[0].toString('hex').should.equal('010203');
+    });
+
+  });
+
 });