1 files changed, 81 insertions, 0 deletions
diff --git a/ui/app/components/send_/send-footer/send-footer.utils.js b/ui/app/components/send_/send-footer/send-footer.utils.js
new file mode 100644
index 000000000..875e7d948
--- /dev/null
+++ b/ui/app/components/send_/send-footer/send-footer.utils.js
@@ -0,0 +1,81 @@
+const ethAbi = require('ethereumjs-abi')
+const ethUtil = require('ethereumjs-util')
+const { TOKEN_TRANSFER_FUNCTION_SIGNATURE } = require('../send.constants')
+
+function addHexPrefixToObjectValues (obj) {
+  return Object.keys(obj).reduce((newObj, key) => {
+    return { ...newObj, [key]: ethUtil.addHexPrefix(obj[key]) }
+  }, {})
+}
+
+function constructTxParams ({ selectedToken, to, amount, from, gas, gasPrice }) {
+  const txParams = {
+    from,
+    value: '0',
+    gas,
+    gasPrice,
+  }
+
+  if (!selectedToken) {
+    txParams.value = amount
+    txParams.to = to
+  }
+
+  const hexPrefixedTxParams = addHexPrefixToObjectValues(txParams)
+
+  return hexPrefixedTxParams
+}
+
+function constructUpdatedTx ({
+  amount,
+  editingTransactionId,
+  from,
+  gas,
+  gasPrice,
+  selectedToken,
+  to,
+  unapprovedTxs,
+}) {
+  const editingTx = {
+    ...unapprovedTxs[editingTransactionId],
+    txParams: addHexPrefixToObjectValues({ from, gas, gasPrice }),
+  }
+
+  if (selectedToken) {
+    const data = TOKEN_TRANSFER_FUNCTION_SIGNATURE + Array.prototype.map.call(
+      ethAbi.rawEncode(['address', 'uint256'], [to, ethUtil.addHexPrefix(amount)]),
+      x => ('00' + x.toString(16)).slice(-2)
+    ).join('')
+
+    Object.assign(editingTx.txParams, addHexPrefixToObjectValues({
+      value: '0',
+      to: selectedToken.address,
+      data,
+    }))
+  } else {
+    const { data } = unapprovedTxs[editingTransactionId].txParams
+
+    Object.assign(editingTx.txParams, addHexPrefixToObjectValues({
+      value: amount,
+      to,
+      data,
+    }))
+
+    if (typeof editingTx.txParams.data === 'undefined') {
+      delete editingTx.txParams.data
+    }
+  }
+
+  return editingTx
+}
+
+function addressIsNew (toAccounts, newAddress) {
+  return !toAccounts.find(({ address }) => newAddress === address)
+}
+
+module.exports = {
+  addressIsNew,
+  constructTxParams,
+  constructUpdatedTx,
+  addHexPrefixToObjectValues,
+}