new tx - calculate estimatedGas and show thing in tx-details (#441)

* new tx - calculate estimatedGas and show thing in tx-details

* Bump changelog

4 files changed, 46 insertions, 25 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 96f7749c8..464a39569 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 - New vaults now generate only one wallet instead of three.
 - Bumped version of web3 provider engine.
 - Fixed bug where some lowercase or uppercase addresses were not being recognized as valid.
+- Fixed bug where gas cost was misestimated on the tx confirmation view.
 
 ## 2.6.0 2016-07-11
 
diff --git a/app/scripts/lib/idStore.js b/app/scripts/lib/idStore.js
index 133078668..2c8e9108b 100644
--- a/app/scripts/lib/idStore.js
+++ b/app/scripts/lib/idStore.js
@@ -1,6 +1,8 @@
 const EventEmitter = require('events').EventEmitter
 const inherits = require('util').inherits
+const async = require('async')
 const ethUtil = require('ethereumjs-util')
+const EthQuery = require('eth-query')
 const LightwalletKeyStore = require('eth-lightwallet').keystore
 const clone = require('clone')
 const extend = require('xtend')
@@ -197,35 +199,53 @@ IdentityStore.prototype.addUnconfirmedTransaction = function (txParams, onTxDone
     time: time,
     status: 'unconfirmed',
   }
-  configManager.addTx(txData)
+  
   console.log('addUnconfirmedTransaction:', txData)
 
   // keep the onTxDoneCb around for after approval/denial (requires user interaction)
   // This onTxDoneCb fires completion to the Dapp's write operation.
   self._unconfTxCbs[txId] = onTxDoneCb
 
-  // perform static analyis on the target contract code
   var provider = self._ethStore._query.currentProvider
-  if (txParams.to) {
-    provider.sendAsync({ id: 1, method: 'eth_getCode', params: [txParams.to, 'latest'] }, function (err, res) {
-      if (err) return didComplete(err)
-      if (res.error) return didComplete(res.error)
-      var code = ethUtil.toBuffer(res.result)
-      if (code !== '0x') {
-        var ops = ethBinToOps(code)
-        var containsDelegateCall = ops.some((op) => op.name === 'DELEGATECALL')
-        txData.containsDelegateCall = containsDelegateCall
-        didComplete()
-      } else {
-        didComplete()
-      }
+  var query = new EthQuery(provider)
+
+  // calculate metadata for tx
+  async.parallel([
+    analyzeForDelegateCall,
+    estimateGas,
+  ], didComplete)
+
+  // perform static analyis on the target contract code
+  function analyzeForDelegateCall(cb){
+    if (txParams.to) {
+      query.getCode(txParams.to, function (err, result) {
+        if (err) return cb(err)
+        var code = ethUtil.toBuffer(result)
+        if (code !== '0x') {
+          var ops = ethBinToOps(code)
+          var containsDelegateCall = ops.some((op) => op.name === 'DELEGATECALL')
+          txData.containsDelegateCall = containsDelegateCall
+          cb()
+        } else {
+          cb()
+        }
+      })
+    } else {
+      cb()
+    }
+  }
+
+  function estimateGas(cb){
+    query.estimateGas(txParams, function(err, result){
+      if (err) return cb(err)
+      txData.estimatedGas = result
+      cb()
     })
-  } else {
-    didComplete()
   }
 
   function didComplete (err) {
     if (err) return cb(err)
+    configManager.addTx(txData)
     // signal update
     self._didUpdate()
     // signal completion of add tx
diff --git a/package.json b/package.json
index 4438092c2..8d2540ef2 100644
--- a/package.json
+++ b/package.json
@@ -32,6 +32,7 @@
     "end-of-stream": "^1.1.0",
     "eth-bin-to-ops": "^1.0.0",
     "eth-lightwallet": "^2.3.3",
+    "eth-query": "^1.0.3",
     "eth-store": "^1.1.0",
     "ethereumjs-tx": "^1.0.0",
     "ethereumjs-util": "^4.4.0",
diff --git a/ui/app/components/pending-tx-details.js b/ui/app/components/pending-tx-details.js
index 9a06ad09e..a6f72a89b 100644
--- a/ui/app/components/pending-tx-details.js
+++ b/ui/app/components/pending-tx-details.js
@@ -11,9 +11,6 @@ const nameForAddress = require('../../lib/contract-namer')
 const ethUtil = require('ethereumjs-util')
 const BN = ethUtil.BN
 
-const baseGasFee = new BN('21000', 10)
-const gasCost = new BN('4a817c800', 16)
-const baseFeeHex = baseGasFee.mul(gasCost).toString(16)
 
 module.exports = PendingTxDetails
 
@@ -33,9 +30,11 @@ PTXP.render = function () {
   var identity = props.identities[address] || { address: address }
   var balance = props.accounts[address].balance
 
-  var gasCost = ethUtil.stripHexPrefix(txParams.gas || baseFeeHex)
-  var txValue = ethUtil.stripHexPrefix(txParams.value || '0x0')
-  var maxCost = ((new BN(txValue, 16)).add(new BN(gasCost, 16))).toString(16)
+  var gasCost = new BN(ethUtil.stripHexPrefix(txParams.gas || txData.estimatedGas), 16)
+  var gasPrice = new BN(ethUtil.stripHexPrefix(txParams.gasPrice || '0x4a817c800'), 16)
+  var txFee = gasCost.mul(gasPrice)
+  var txValue = new BN(ethUtil.stripHexPrefix(txParams.value || '0x0'), 16)
+  var maxCost = txValue.add(txFee)
   var dataLength = txParams.data ? (txParams.data.length - 2) / 2 : 0
 
   var imageify = props.imageifyIdenticons === undefined ? true : props.imageifyIdenticons
@@ -112,7 +111,7 @@ PTXP.render = function () {
 
         h('.cell.row', [
           h('.cell.label', 'Max Transaction Fee'),
-          h('.cell.value', formatBalance(gasCost)),
+          h('.cell.value', formatBalance(txFee.toString(16))),
         ]),
 
         h('.cell.row', {
@@ -130,7 +129,7 @@ PTXP.render = function () {
             },
           }, [
             h(EtherBalance, {
-              value: maxCost,
+              value: maxCost.toString(16),
               inline: true,
               labelColor: 'black',
               fontSize: '16px',