Fetch deposit BTC address (contract code)

client/src/Deposit.js

@@ -1,9 +1,4 @@
-import {
-  TBTCSystem,
-  TBTCToken,
-  KeepBridge,
-  DepositFactory
-} from './eth/contracts'
+import { DepositFactory, KeepBridge, TBTCSystem, TBTCToken } from './eth/contracts';
 
 /**
  * Creates a new deposit and returns its address
@@ -32,6 +27,5 @@ export async function createDeposit() {
   })
 
   const depositAddress = logs[0].args.depositCloneAddress
-
   return depositAddress
 }

client/src/FundingTransaction.js

@@ -1,12 +1,61 @@
-const Address = require('tbtc-helpers').Address
+import { Network, publicKeyToP2WPKHaddress } from 'tbtc-helpers'
+import { Deposit, TBTCSystem } from './eth/contracts'
 
-// PAGE 3: Pay BTC
-async function getAddress(depositAddress) {
-  // TODO: Implement:
-  // 1. Get keep public key from the deposit
-  // 2. Calculate P2WPKH address from the key
+
+
+
+/**
+ * Requests a Bitcoin public key for a Deposit and returns it as a Bitcoin address
+ * @param {string} depositAddress the address of a Deposit contract
+ * @return {string} a bech32-encoded Bitcoin address, generated from a SegWit P2WPKH script
+ */
+export async function getDepositBtcAddress(depositAddress) {
+  const tbtcSystem = await TBTCSystem.deployed()
+
+  // 1. Request public key from the deposit
+  const deposit = await Deposit.at(depositAddress)
+
+  console.log(`Call getPublicKey for deposit [${deposit.address}]`)
+
+  await deposit.retrieveSignerPubkey()
+    .catch((err) => {
+      // This can happen when the public key was already retrieved before 
+      // and we may succeed to get it with tbtcSystem.getPastEvents in the following lines
+      // TODO: there may be other errors that this allows to pass, refactor in future
+      console.error(`retrieveSignerPubkey failed: ${err}`)
+    })
+
+  // 2. Parse the logs to get the public key
+  // since the public key event is emitted in another contract, we
+  // can't get this from result.logs
+  const eventList = await tbtcSystem.getPastEvents(
+    'RegisteredPubkey',
+    {
+      fromBlock: '0',
+      toBlock: 'latest',
+      filter: { _depositContractAddress: depositAddress }
+    }
+  )
+
+  if (eventList.length == 0) {
+    throw new Error(`couldn't find RegisteredPubkey event for deposit address: ${depositAddress}`)
+  }
+
+  let publicKeyX = eventList[0].args._signingGroupPubkeyX
+  let publicKeyY = eventList[0].args._signingGroupPubkeyY
+  publicKeyX = publicKeyX.replace('0x', '')
+  publicKeyY = publicKeyY.replace('0x', '')
+
+  console.log(`Registered public key for deposit ${depositAddress}:\nX: ${publicKeyX}\nY: ${publicKeyY}`)
+
+  const btcAddress = publicKeyToP2WPKHaddress(
+    `${publicKeyX}${publicKeyY}`,
+    Network.testnet
+  )
+  return btcAddress
 }
 
+
 /**
  * Funding transaction details.
  * @typedef FundingTransaction
@@ -23,12 +72,12 @@ async function getAddress(depositAddress) {
  * @param {number} expectedValue Expected transaction output value (satoshis).
  * @return {FundingTransaction} Transaction details.
  */
-async function watchForFundingTransaction(electrumClient, bitcoinAddress, expectedValue) {
+export async function watchForFundingTransaction(electrumClient, bitcoinAddress, expectedValue) {
   const script = Address.addressToScript(bitcoinAddress)
 
   // This function is used as a callback to electrum client. It is invoked when
   // am existing or a new transaction is found.
-  const findFundingTransaction = async function(status) {
+  const findFundingTransaction = async function (status) {
     // Check if status is null which means there are not transactions for the
     // script.
     if (status == null) {
@@ -62,12 +111,8 @@ async function watchForFundingTransaction(electrumClient, bitcoinAddress, expect
 }
 
 // PAGE 4. WAITING FOR CONFIRMATIONS
-async function waitForConfirmations(transactionID) {
+export async function waitForConfirmations(transactionID) {
   // TODO: Implement:
   // 1. Wait for required number of confirmations for the transaction
   // 2. Monitor confirmations on the chain and return when ready
-}
-
-module.exports = {
-  getAddress, watchForFundingTransaction, waitForConfirmations,
-}
+}

client/src/index.js

@@ -1,2 +1,3 @@
 export * from './Deposit'
+export * from './FundingTransaction'
 export * from './eth/contracts'

client/test/DepositTest.js

@@ -1,10 +1,7 @@
-import { createDeposit, setDefaults } from '../src'
+import { createDeposit, setDefaults, getDepositBtcAddress } from '../src'
 
 import {
-    TBTCSystem,
-    TBTCToken,
-    KeepBridge,
-    Deposit
+  Deposit
 } from '../src/eth/contracts'
 
 const Web3 = require('web3')
@@ -29,7 +26,7 @@ describe.skip('Ethereum helpers', async () => {
     Web3.providers.HttpProvider.prototype.sendAsync = Web3.providers.HttpProvider.prototype.send
 
     web3 = new Web3(new Web3.providers.HttpProvider('http://localhost:8545'))
-        await setDefaults(web3)
+    await setDefaults(web3)
   })
 
   it('#createDeposit', async () => {
@@ -38,4 +35,10 @@ describe.skip('Ethereum helpers', async () => {
 
     expect(await deposit.getCurrentState()).to.eq.BN('1')
   })
-})
+
+  it('#getDepositBtcAddress', async () => {
+    const depositAddress = await createDeposit()
+    const btcAddress = await getDepositBtcAddress(depositAddress)
+    expect(btcAddress.substring(0, 2)).to.equal('tb')
+  })
+})

lib/tbtc-helpers/package.json

@@ -2,6 +2,7 @@
   "name": "tbtc-helpers",
   "version": "0.0.1",
   "description": "",
+  "main": "index.js",
   "scripts": {
     "test": "mocha --timeout 5000",
     "js:lint": "eslint .",

package.json

@@ -16,6 +16,7 @@
     "redux": "^4.0.4",
     "redux-saga": "^1.0.5",
     "tbtc-client": "file:client",
+    "tbtc-helpers": "file:lib/tbtc-helpers",
     "truffle": "^5.0.29",
     "truffle-contract": "^4.0.26",
     "web3": "^1.2.0"