Merge pull request #215 from weilu/feendust

Fee and dust

src/networks.js

@@ -1,6 +1,7 @@
 // https://en.bitcoin.it/wiki/List_of_address_prefixes
 // Dogecoin BIP32 is a proposed standard: https://bitcointalk.org/index.php?topic=409731
-module.exports = {
+
+var networks = {
   bitcoin: {
     magicPrefix: '\x18Bitcoin Signed Message:\n',
     bip32: {
@@ -9,7 +10,10 @@ module.exports = {
     },
     pubKeyHash: 0x00,
     scriptHash: 0x05,
-    wif: 0x80
+    wif: 0x80,
+    dustThreshold: 546, // https://github.com/bitcoin/bitcoin/blob/v0.9.2/src/core.h#L151-L162
+    feePerKb: 10000, // https://github.com/bitcoin/bitcoin/blob/v0.9.2/src/main.cpp#L53
+    estimateFee: estimateFee('bitcoin')
   },
   dogecoin: {
     magicPrefix: '\x19Dogecoin Signed Message:\n',
@@ -19,7 +23,11 @@ module.exports = {
     },
     pubKeyHash: 0x1e,
     scriptHash: 0x16,
-    wif: 0x9e
+    wif: 0x9e,
+    dustThreshold: 0, // https://github.com/dogecoin/dogecoin/blob/v1.7.1/src/core.h#L155-L160
+    dustSoftThreshold: 100000000, // https://github.com/dogecoin/dogecoin/blob/v1.7.1/src/main.h#L62
+    feePerKb: 100000000, // https://github.com/dogecoin/dogecoin/blob/v1.7.1/src/main.cpp#L58
+    estimateFee: estimateFee('dogecoin')
   },
   litecoin: {
     magicPrefix: '\x19Litecoin Signed Message:\n',
@@ -29,7 +37,11 @@ module.exports = {
     },
     pubKeyHash: 0x30,
     scriptHash: 0x05,
-    wif: 0xb0
+    wif: 0xb0,
+    dustThreshold: 0, // https://github.com/litecoin-project/litecoin/blob/v0.8.7.2/src/main.cpp#L360-L365
+    dustSoftThreshold: 100000, // https://github.com/litecoin-project/litecoin/blob/v0.8.7.2/src/main.h#L53
+    feePerKb: 100000, // https://github.com/litecoin-project/litecoin/blob/v0.8.7.2/src/main.cpp#L56
+    estimateFee: estimateFee('litecoin')
   },
   testnet: {
     magicPrefix: '\x18Bitcoin Signed Message:\n',
@@ -39,6 +51,30 @@ module.exports = {
     },
     pubKeyHash: 0x6f,
     scriptHash: 0xc4,
-    wif: 0xef
+    wif: 0xef,
+    dustThreshold: 546,
+    feePerKb: 10000,
+    estimateFee: estimateFee('bitcoin')
   }
 }
+
+function estimateFee(type) {
+  return function(tx) {
+    var network = networks[type]
+    var baseFee = network.feePerKb
+    var byteSize = tx.toBuffer().length
+
+    var fee = baseFee * Math.ceil(byteSize / 1000)
+    if(network.dustSoftThreshold == undefined) return fee
+
+    tx.outs.forEach(function(e){
+      if(e.value < network.dustSoftThreshold) {
+        fee += baseFee
+      }
+    })
+
+    return fee
+  }
+}
+
+module.exports = networks

src/wallet.js

@@ -20,9 +20,6 @@ function Wallet(seed, network) {
   this.addresses = []
   this.changeAddresses = []
 
-  // Dust value
-  this.dustThreshold = 5430
-
   // Transaction output data
   this.outputs = {}
 
@@ -182,7 +179,7 @@ function Wallet(seed, network) {
   }
 
   this.createTx = function(to, value, fixedFee, changeAddress) {
-    assert(value > this.dustThreshold, value + ' must be above dust threshold (' + this.dustThreshold + ' Satoshis)')
+    assert(value > network.dustThreshold, value + ' must be above dust threshold (' + network.dustThreshold + ' Satoshis)')
 
     var utxos = getCandidateOutputs(value)
     var accum = 0
@@ -206,7 +203,7 @@ function Wallet(seed, network) {
       if (accum >= subTotal) {
         var change = accum - subTotal
 
-        if (change > this.dustThreshold) {
+        if (change > network.dustThreshold) {
           tx.addOutput(changeAddress || getChangeAddress(), change)
         }
 
@@ -235,13 +232,11 @@ function Wallet(seed, network) {
     return sortByValueDesc
   }
 
-  var feePerKb = 20000
   function estimateFeePadChangeOutput(tx) {
     var tmpTx = tx.clone()
     tmpTx.addOutput(getChangeAddress(), 0)
 
-    var byteSize = tmpTx.toBuffer().length
-    return feePerKb * Math.ceil(byteSize / 1000)
+    return network.estimateFee(tmpTx)
   }
 
   function getChangeAddress() {

test/network.js

@@ -0,0 +1,93 @@
+var assert = require('assert')
+var networks = require('../src/networks')
+var sinon = require('sinon')
+var Transaction = require('../src/transaction')
+
+describe('networks', function() {
+  var txToBuffer
+  before(function(){
+    txToBuffer = sinon.stub(Transaction.prototype, "toBuffer")
+  })
+
+  after(function(){
+    Transaction.prototype.toBuffer.restore()
+  })
+
+  describe('bitcoin', function() {
+    describe('estimateFee', function() {
+      var estimateFee = networks.bitcoin.estimateFee
+
+      it('works at boundry', function() {
+        txToBuffer.returns(new Buffer(1000))
+        var tx = new Transaction()
+        assert.equal(estimateFee(tx), 10000)
+      })
+
+      it('rounds up to the closest kb for estimation', function() {
+        txToBuffer.returns(new Buffer(2800))
+        var tx = new Transaction()
+        assert.equal(estimateFee(tx), 30000)
+      })
+    })
+  })
+
+  describe('dogecoin', function() {
+    describe('estimateFee', function() {
+      var estimateFee = networks.dogecoin.estimateFee
+
+      it('regular fee per kb applies when every output has value no less than DUST_SOFT_LIMIT', function() {
+        txToBuffer.returns(new Buffer(1000))
+        var tx = new Transaction()
+        tx.outs[0] = { value: 100000000 }
+
+        assert.equal(estimateFee(tx), 100000000)
+      })
+
+      it('applies additional fee on every output with value below DUST_SOFT_LIMIT', function() {
+        txToBuffer.returns(new Buffer(1000))
+        var tx = new Transaction()
+        tx.outs[0] = { value: 99999999 }
+        tx.outs[1] = { value: 99999999 }
+
+        assert.equal(estimateFee(tx), 3 * 100000000)
+      })
+
+      it('rounds up to the closest kb for estimation', function() {
+        txToBuffer.returns(new Buffer(2800))
+        var tx = new Transaction()
+
+        assert.equal(estimateFee(tx), 300000000)
+      })
+    })
+  })
+
+  describe('litecoin', function() {
+    describe('estimateFee', function() {
+      var estimateFee = networks.litecoin.estimateFee
+
+      it('regular fee per kb applies when every output has value no less than DUST_SOFT_LIMIT', function() {
+        txToBuffer.returns(new Buffer(1000))
+        var tx = new Transaction()
+        tx.outs[0] = { value: 100000 }
+
+        assert.equal(estimateFee(tx), 100000)
+      })
+
+      it('applies additional fee on every output with value below DUST_SOFT_LIMIT', function() {
+        txToBuffer.returns(new Buffer(1000))
+        var tx = new Transaction()
+        tx.outs[0] = { value: 99999 }
+        tx.outs[1] = { value: 99999 }
+
+        assert.equal(estimateFee(tx), 3 * 100000)
+      })
+
+      it('rounds up to the closest kb for estimation', function() {
+        txToBuffer.returns(new Buffer(2800))
+        var tx = new Transaction()
+
+        assert.equal(estimateFee(tx), 300000)
+      })
+    })
+  })
+})

test/wallet.js

@@ -389,7 +389,7 @@ describe('Wallet', function() {
           "hash": fakeTxId(3),
           "outputIndex": 0,
           "address" : address2,
-          "value": 520000 // enough for value and fee
+          "value": 510000 // enough for value and fee
         }
       ]
       wallet.setUnspentOutputs(utxo)
@@ -417,7 +417,7 @@ describe('Wallet', function() {
       })
 
       it('allows fee to be set to zero', function(){
-        value = 520000
+        value = 510000
         var fee = 0
         var tx = wallet.createTx(to, value, fee)
 
@@ -459,7 +459,7 @@ describe('Wallet', function() {
         }])
 
         var to = 'mt7MyTVVEWnbwpF5hBn6fgnJcv95Syk2ue'
-        var toValue = value - 20000
+        var toValue = value - 10000
 
         var tx = wallet.createTx(to, toValue)
         assert.equal(tx.outs.length, 1)
@@ -516,7 +516,7 @@ describe('Wallet', function() {
 
       describe('change', function(){
         it('uses the last change address if there is any', function(){
-          var fee = 5000
+          var fee = 0
           wallet.generateChangeAddress()
           wallet.generateChangeAddress()
           var tx = wallet.createTx(to, value, fee)
@@ -526,11 +526,11 @@ describe('Wallet', function() {
           var outAddress = Address.fromOutputScript(out.script)
 
           assert.equal(outAddress.toString(), wallet.changeAddresses[1])
-          assert.equal(out.value, 15000)
+          assert.equal(out.value, 10000)
         })
 
         it('generates a change address if there is not any', function(){
-          var fee = 5000
+          var fee = 0
           assert.equal(wallet.changeAddresses.length, 0)
 
           var tx = wallet.createTx(to, value, fee)
@@ -540,7 +540,7 @@ describe('Wallet', function() {
           var outAddress = Address.fromOutputScript(out.script)
 
           assert.equal(outAddress.toString(), wallet.changeAddresses[0])
-          assert.equal(out.value, 15000)
+          assert.equal(out.value, 10000)
         })
 
         it('skips change if it is not above dust threshold', function(){
@@ -569,11 +569,11 @@ describe('Wallet', function() {
 
     describe('when value is below dust threshold', function(){
       it('throws an error', function(){
-        var value = 5430
+        var value = 546
 
         assert.throws(function() {
           wallet.createTx(to, value)
-        }, /5430 must be above dust threshold \(5430 Satoshis\)/)
+        }, /546 must be above dust threshold \(546 Satoshis\)/)
       })
     })
 
@@ -583,7 +583,7 @@ describe('Wallet', function() {
 
         assert.throws(function() {
           wallet.createTx(to, value)
-        }, /Not enough funds \(incl. fee\): 1420000 < 1420001/)
+        }, /Not enough funds \(incl. fee\): 1410000 < 1410001/)
       })
     })
   })