WA-238 Added ethTransactions helper function

src/wallets/ethTransactions.js

@@ -0,0 +1,52 @@
+// @flow
+import { BigNumber } from 'bignumber.js'
+import { getWeb3 } from '~/wallets/getWeb3'
+import { promisify } from '~/utils/promisify'
+
+// const MAINNET_NETWORK = 1
+
+const calculateGasPrice = async () => {
+/*
+  const web3 = getWeb3()
+  const { network } = web3.version
+  const isMainnet = MAINNET_NETWORK === network
+
+  const url = isMainnet
+    ? 'https://safe-relay.staging.gnosisdev.com/api/v1/gas-station/'
+    : 'https://safe-relay.dev.gnosisdev.com/'
+*/
+
+  const response = await fetch('https://ethgasstation.info/json/ethgasAPI.json', { mode: 'cors' })
+  if (!response.ok) {
+    throw new Error('Error querying gast station')
+  }
+
+  const json = await response.json()
+
+  return new BigNumber(json.average).multipliedBy(1e8).toString()
+}
+
+const calculateGasOf = async (data: Object, from: string, to: string) => {
+  const web3 = getWeb3()
+
+  return promisify(cb => web3.eth.estimateGas({ data, from, to }, cb))
+}
+
+const executeTransaction = async (data: Object, from: string, to: string) => {
+  const web3 = getWeb3()
+
+  const gas = await calculateGasOf(data, from, to) + 2000
+
+  let gasPrice
+  try {
+    gasPrice = await calculateGasPrice()
+  } catch (err) {
+    gasPrice = await promisify(cb => web3.eth.getGasPrice(cb))
+  }
+
+  return promisify(cb => web3.eth.sendTransaction({
+    from, to, data, gas, gasPrice,
+  }, cb))
+}
+
+export default executeTransaction