TxBuilder: re-order functions to project standard

Author: dcousens

src/transaction_builder.js

@@ -15,6 +15,90 @@ function TransactionBuilder() {
   this.tx = new Transaction()
 }
 
+// Static constructors
+TransactionBuilder.fromTransaction = function(transaction) {
+  var txb = new TransactionBuilder()
+
+  // Extract/add inputs
+  transaction.ins.forEach(function(txin) {
+    txb.addInput(txin.hash, txin.index, txin.sequence)
+  })
+
+  // Extract/add outputs
+  transaction.outs.forEach(function(txout) {
+    txb.addOutput(txout.script, txout.value)
+  })
+
+  // Extract/add signatures
+  transaction.ins.forEach(function(txin) {
+    // Ignore empty scripts
+    if (txin.script.buffer.length === 0) return
+
+    var redeemScript
+    var scriptSig = txin.script
+    var scriptType = scripts.classifyInput(scriptSig)
+
+    // Re-classify if P2SH
+    if (scriptType === 'scripthash') {
+      redeemScript = Script.fromBuffer(scriptSig.chunks.slice(-1)[0])
+      scriptSig = Script.fromChunks(scriptSig.chunks.slice(0, -1))
+
+      scriptType = scripts.classifyInput(scriptSig)
+      assert.equal(scripts.classifyOutput(redeemScript), scriptType, 'Non-matching scriptSig and scriptPubKey in input')
+    }
+
+    // Extract hashType, pubKeys and signatures
+    var hashType, pubKeys, signatures
+
+    switch (scriptType) {
+      case 'pubkeyhash':
+        var parsed = ECSignature.parseScriptSignature(scriptSig.chunks[0])
+        var pubKey = ECPubKey.fromBuffer(scriptSig.chunks[1])
+
+        hashType = parsed.hashType
+        pubKeys = [pubKey]
+        signatures = [parsed.signature]
+
+        break
+
+      case 'multisig':
+        var scriptSigs = scriptSig.chunks.slice(1) // ignore OP_0
+        var parsed = scriptSigs.map(function(scriptSig) {
+          return ECSignature.parseScriptSignature(scriptSig)
+        })
+
+        hashType = parsed[0].hashType
+        pubKeys = []
+        signatures = parsed.map(function(p) { return p.signature })
+
+        break
+
+      case 'pubkey':
+        var parsed = ECSignature.parseScriptSignature(scriptSig.chunks[0])
+
+        hashType = parsed.hashType
+        pubKeys = []
+        signatures = [parsed.signature]
+
+        break
+
+      default:
+        assert(false, scriptType + ' not supported')
+    }
+
+    txb.signatures[txin.index] = {
+      hashType: hashType,
+      pubKeys: pubKeys,
+      redeemScript: redeemScript,
+      scriptType: scriptType,
+      signatures: signatures
+    }
+  })
+
+  return txb
+}
+
+// Operations
 TransactionBuilder.prototype.addInput = function(prevTx, index, sequence, prevOutScript) {
   var prevOutHash
 
@@ -63,55 +147,6 @@ TransactionBuilder.prototype.addOutput = function(scriptPubKey, value) {
   return this.tx.addOutput(scriptPubKey, value)
 }
 
-TransactionBuilder.prototype.sign = function(index, privKey, redeemScript, hashType) {
-  assert(this.tx.ins.length >= index, 'No input at index: ' + index)
-  hashType = hashType || Transaction.SIGHASH_ALL
-
-  var prevOutScript = this.prevOutScripts[index]
-  var prevOutType = this.prevOutTypes[index]
-
-  var scriptType, hash
-  if (redeemScript) {
-    prevOutScript = prevOutScript || scripts.scriptHashOutput(redeemScript.getHash())
-    prevOutType = prevOutType || 'scripthash'
-
-    assert.equal(prevOutType, 'scripthash', 'PrevOutScript must be P2SH')
-
-    scriptType = scripts.classifyOutput(redeemScript)
-
-    assert.notEqual(scriptType, 'scripthash', 'RedeemScript can\'t be P2SH')
-    assert.notEqual(scriptType, 'nonstandard', 'RedeemScript not supported (nonstandard)')
-
-    hash = this.tx.hashForSignature(index, redeemScript, hashType)
-
-  } else {
-    prevOutScript = prevOutScript || privKey.pub.getAddress().toOutputScript()
-    scriptType = prevOutType || 'pubkeyhash'
-
-    assert.notEqual(scriptType, 'scripthash', 'PrevOutScript requires redeemScript')
-
-    hash = this.tx.hashForSignature(index, prevOutScript, hashType)
-  }
-
-  if (!(index in this.signatures)) {
-    this.signatures[index] = {
-      hashType: hashType,
-      pubKeys: [],
-      redeemScript: redeemScript,
-      scriptType: scriptType,
-      signatures: []
-    }
-  }
-
-  var input = this.signatures[index]
-  assert.equal(input.hashType, hashType, 'Inconsistent hashType')
-  assert.deepEqual(input.redeemScript, redeemScript, 'Inconsistent redeemScript')
-
-  var signature = privKey.sign(hash)
-  input.pubKeys.push(privKey.pub)
-  input.signatures.push(signature)
-}
-
 TransactionBuilder.prototype.build = function() {
   return this.__build(false)
 }
@@ -173,86 +208,53 @@ TransactionBuilder.prototype.__build = function(allowIncomplete) {
   return tx
 }
 
-TransactionBuilder.fromTransaction = function(transaction) {
-  var txb = new TransactionBuilder()
-
-  // Extract/add inputs
-  transaction.ins.forEach(function(txin) {
-    txb.addInput(txin.hash, txin.index, txin.sequence)
-  })
-
-  // Extract/add outputs
-  transaction.outs.forEach(function(txout) {
-    txb.addOutput(txout.script, txout.value)
-  })
-
-  // Extract/add signatures
-  transaction.ins.forEach(function(txin) {
-    // Ignore empty scripts
-    if (txin.script.buffer.length === 0) return
-
-    var redeemScript
-    var scriptSig = txin.script
-    var scriptType = scripts.classifyInput(scriptSig)
-
-    // Re-classify if P2SH
-    if (scriptType === 'scripthash') {
-      redeemScript = Script.fromBuffer(scriptSig.chunks.slice(-1)[0])
-      scriptSig = Script.fromChunks(scriptSig.chunks.slice(0, -1))
-
-      scriptType = scripts.classifyInput(scriptSig)
-      assert.equal(scripts.classifyOutput(redeemScript), scriptType, 'Non-matching scriptSig and scriptPubKey in input')
-    }
-
-    // Extract hashType, pubKeys and signatures
-    var hashType, pubKeys, signatures
-
-    switch (scriptType) {
-      case 'pubkeyhash':
-        var parsed = ECSignature.parseScriptSignature(scriptSig.chunks[0])
-        var pubKey = ECPubKey.fromBuffer(scriptSig.chunks[1])
+TransactionBuilder.prototype.sign = function(index, privKey, redeemScript, hashType) {
+  assert(this.tx.ins.length >= index, 'No input at index: ' + index)
+  hashType = hashType || Transaction.SIGHASH_ALL
 
-        hashType = parsed.hashType
-        pubKeys = [pubKey]
-        signatures = [parsed.signature]
+  var prevOutScript = this.prevOutScripts[index]
+  var prevOutType = this.prevOutTypes[index]
 
-        break
+  var scriptType, hash
+  if (redeemScript) {
+    prevOutScript = prevOutScript || scripts.scriptHashOutput(redeemScript.getHash())
+    prevOutType = prevOutType || 'scripthash'
 
-      case 'multisig':
-        var scriptSigs = scriptSig.chunks.slice(1) // ignore OP_0
-        var parsed = scriptSigs.map(function(scriptSig) {
-          return ECSignature.parseScriptSignature(scriptSig)
-        })
+    assert.equal(prevOutType, 'scripthash', 'PrevOutScript must be P2SH')
 
-        hashType = parsed[0].hashType
-        pubKeys = []
-        signatures = parsed.map(function(p) { return p.signature })
+    scriptType = scripts.classifyOutput(redeemScript)
 
-        break
+    assert.notEqual(scriptType, 'scripthash', 'RedeemScript can\'t be P2SH')
+    assert.notEqual(scriptType, 'nonstandard', 'RedeemScript not supported (nonstandard)')
 
-      case 'pubkey':
-        var parsed = ECSignature.parseScriptSignature(scriptSig.chunks[0])
+    hash = this.tx.hashForSignature(index, redeemScript, hashType)
 
-        hashType = parsed.hashType
-        pubKeys = []
-        signatures = [parsed.signature]
+  } else {
+    prevOutScript = prevOutScript || privKey.pub.getAddress().toOutputScript()
+    scriptType = prevOutType || 'pubkeyhash'
 
-        break
+    assert.notEqual(scriptType, 'scripthash', 'PrevOutScript requires redeemScript')
 
-      default:
-        assert(false, scriptType + ' not supported')
-    }
+    hash = this.tx.hashForSignature(index, prevOutScript, hashType)
+  }
 
-    txb.signatures[txin.index] = {
+  if (!(index in this.signatures)) {
+    this.signatures[index] = {
       hashType: hashType,
-      pubKeys: pubKeys,
+      pubKeys: [],
       redeemScript: redeemScript,
       scriptType: scriptType,
-      signatures: signatures
+      signatures: []
     }
-  })
+  }
 
-  return txb
+  var input = this.signatures[index]
+  assert.equal(input.hashType, hashType, 'Inconsistent hashType')
+  assert.deepEqual(input.redeemScript, redeemScript, 'Inconsistent redeemScript')
+
+  var signature = privKey.sign(hash)
+  input.pubKeys.push(privKey.pub)
+  input.signatures.push(signature)
 }
 
 module.exports = TransactionBuilder