From d0c009adff53d94414cf51028eff490e0452a3c9 Mon Sep 17 00:00:00 2001
From: Brandon Millman <brandon.millman@gmail.com>
Date: Wed, 7 Nov 2018 18:02:24 -0800
Subject: [PATCH 1/4] feat(instant): fetch account address at startup and drive
 account state changes

---
 .../instant/src/components/buy_button.tsx     | 21 +++++---------
 .../components/buy_order_state_buttons.tsx    |  2 ++
 .../components/zero_ex_instant_provider.tsx   |  4 +--
 packages/instant/src/constants.ts             | 14 ++++++++-
 .../selected_asset_buy_order_state_buttons.ts |  6 +++-
 packages/instant/src/redux/actions.ts         |  8 +++++
 packages/instant/src/redux/async_data.ts      | 21 ++++++++++++++
 packages/instant/src/redux/reducer.ts         | 29 ++++++++++++++++++-
 .../src/util/provider_state_factory.ts        |  8 +----
 9 files changed, 88 insertions(+), 25 deletions(-)

diff --git a/packages/instant/src/components/buy_button.tsx b/packages/instant/src/components/buy_button.tsx
index 515cd18e92..f24bb57eeb 100644
--- a/packages/instant/src/components/buy_button.tsx
+++ b/packages/instant/src/components/buy_button.tsx
@@ -16,6 +16,7 @@ import { Button } from './ui/button';
 import { Text } from './ui/text';
 
 export interface BuyButtonProps {
+    accountAddress?: string;
     buyQuote?: BuyQuote;
     assetBuyer: AssetBuyer;
     affiliateInfo?: AffiliateInfo;
@@ -34,7 +35,8 @@ export class BuyButton extends React.Component<BuyButtonProps> {
         onBuyFailure: util.boundNoop,
     };
     public render(): React.ReactNode {
-        const shouldDisableButton = _.isUndefined(this.props.buyQuote);
+        const { buyQuote, accountAddress } = this.props;
+        const shouldDisableButton = _.isUndefined(buyQuote) || _.isUndefined(accountAddress);
         return (
             <Button width="100%" onClick={this._handleClick} isDisabled={shouldDisableButton}>
                 <Text fontColor={ColorOption.white} fontWeight={600} fontSize="20px">
@@ -45,30 +47,25 @@ export class BuyButton extends React.Component<BuyButtonProps> {
     }
     private readonly _handleClick = async () => {
         // The button is disabled when there is no buy quote anyway.
-        const { buyQuote, assetBuyer, affiliateInfo } = this.props;
-        if (_.isUndefined(buyQuote)) {
+        const { buyQuote, assetBuyer, affiliateInfo, accountAddress } = this.props;
+        if (_.isUndefined(buyQuote) || _.isUndefined(accountAddress)) {
             return;
         }
-
         this.props.onValidationPending(buyQuote);
-
-        // TODO(bmillman): move address and balance fetching to the async state
+        // TODO(bmillman): move balance fetching to the async state and get rid of web3 wrapper here
         const web3Wrapper = new Web3Wrapper(assetBuyer.provider);
-        const takerAddress = await getBestAddress(web3Wrapper);
-
-        const hasSufficientEth = await balanceUtil.hasSufficientEth(takerAddress, buyQuote, web3Wrapper);
+        const hasSufficientEth = await balanceUtil.hasSufficientEth(accountAddress, buyQuote, web3Wrapper);
         if (!hasSufficientEth) {
             this.props.onValidationFail(buyQuote, ZeroExInstantError.InsufficientETH);
             return;
         }
-
         let txHash: string | undefined;
         const gasInfo = await gasPriceEstimator.getGasInfoAsync();
         const feeRecipient = oc(affiliateInfo).feeRecipient();
         try {
             txHash = await assetBuyer.executeBuyQuoteAsync(buyQuote, {
                 feeRecipient,
-                takerAddress,
+                takerAddress: accountAddress,
                 gasPrice: gasInfo.gasPriceInWei,
             });
         } catch (e) {
@@ -83,7 +80,6 @@ export class BuyButton extends React.Component<BuyButtonProps> {
             }
             throw e;
         }
-
         const startTimeUnix = new Date().getTime();
         const expectedEndTimeUnix = startTimeUnix + gasInfo.estimatedTimeMs;
         this.props.onBuyProcessing(buyQuote, txHash, startTimeUnix, expectedEndTimeUnix);
@@ -96,7 +92,6 @@ export class BuyButton extends React.Component<BuyButtonProps> {
             }
             throw e;
         }
-
         this.props.onBuySuccess(buyQuote, txHash);
     };
 }
diff --git a/packages/instant/src/components/buy_order_state_buttons.tsx b/packages/instant/src/components/buy_order_state_buttons.tsx
index 3d0ede7b1d..b15415e719 100644
--- a/packages/instant/src/components/buy_order_state_buttons.tsx
+++ b/packages/instant/src/components/buy_order_state_buttons.tsx
@@ -13,6 +13,7 @@ import { Flex } from './ui/flex';
 import { Text } from './ui/text';
 
 export interface BuyOrderStateButtonProps {
+    accountAddress?: string;
     buyQuote?: BuyQuote;
     buyOrderProcessingState: OrderProcessState;
     assetBuyer: AssetBuyer;
@@ -52,6 +53,7 @@ export const BuyOrderStateButtons: React.StatelessComponent<BuyOrderStateButtonP
 
     return (
         <BuyButton
+            accountAddress={props.accountAddress}
             buyQuote={props.buyQuote}
             assetBuyer={props.assetBuyer}
             affiliateInfo={props.affiliateInfo}
diff --git a/packages/instant/src/components/zero_ex_instant_provider.tsx b/packages/instant/src/components/zero_ex_instant_provider.tsx
index 1fb5cf64fd..fa0588b71c 100644
--- a/packages/instant/src/components/zero_ex_instant_provider.tsx
+++ b/packages/instant/src/components/zero_ex_instant_provider.tsx
@@ -92,12 +92,12 @@ export class ZeroExInstantProvider extends React.Component<ZeroExInstantProvider
             // tslint:disable-next-line:no-floating-promises
             asyncData.fetchAvailableAssetDatasAndDispatchToStore(this._store);
         }
-
+        // tslint:disable-next-line:no-floating-promises
+        asyncData.fetchAccountInfoAndDispatchToStore(this._store);
         // warm up the gas price estimator cache just in case we can't
         // grab the gas price estimate when submitting the transaction
         // tslint:disable-next-line:no-floating-promises
         gasPriceEstimator.getGasInfoAsync();
-
         // tslint:disable-next-line:no-floating-promises
         this._flashErrorIfWrongNetwork();
     }
diff --git a/packages/instant/src/constants.ts b/packages/instant/src/constants.ts
index 00521b56e6..705313ce74 100644
--- a/packages/instant/src/constants.ts
+++ b/packages/instant/src/constants.ts
@@ -1,6 +1,6 @@
 import { BigNumber } from '@0x/utils';
 
-import { Network } from './types';
+import { AccountNotReady, AccountState, Network } from './types';
 
 export const BIG_NUMBER_ZERO = new BigNumber(0);
 export const ETH_DECIMALS = 18;
@@ -21,3 +21,15 @@ export const ETHEREUM_NODE_URL_BY_NETWORK = {
     [Network.Kovan]: 'https://kovan.infura.io/',
 };
 export const BLOCK_POLLING_INTERVAL_MS = 10000; // 10s
+export const NO_ACCOUNT: AccountNotReady = {
+    state: AccountState.None,
+};
+export const LOADING_ACCOUNT: AccountNotReady = {
+    state: AccountState.Loading,
+};
+export const LOCKED_ACCOUNT: AccountNotReady = {
+    state: AccountState.Locked,
+};
+export const ERROR_ACCOUNT: AccountNotReady = {
+    state: AccountState.Error,
+};
diff --git a/packages/instant/src/containers/selected_asset_buy_order_state_buttons.ts b/packages/instant/src/containers/selected_asset_buy_order_state_buttons.ts
index c3a5e88b99..2678d4a369 100644
--- a/packages/instant/src/containers/selected_asset_buy_order_state_buttons.ts
+++ b/packages/instant/src/containers/selected_asset_buy_order_state_buttons.ts
@@ -7,11 +7,12 @@ import { Dispatch } from 'redux';
 import { BuyOrderStateButtons } from '../components/buy_order_state_buttons';
 import { Action, actions } from '../redux/actions';
 import { State } from '../redux/reducer';
-import { AffiliateInfo, OrderProcessState, ZeroExInstantError } from '../types';
+import { AccountState, AffiliateInfo, OrderProcessState, ZeroExInstantError } from '../types';
 import { errorFlasher } from '../util/error_flasher';
 import { etherscanUtil } from '../util/etherscan';
 
 interface ConnectedState {
+    accountAddress?: string;
     buyQuote?: BuyQuote;
     buyOrderProcessingState: OrderProcessState;
     assetBuyer: AssetBuyer;
@@ -31,7 +32,10 @@ interface ConnectedDispatch {
 export interface SelectedAssetBuyOrderStateButtons {}
 const mapStateToProps = (state: State, _ownProps: SelectedAssetBuyOrderStateButtons): ConnectedState => {
     const assetBuyer = state.providerState.assetBuyer;
+    const account = state.providerState.account;
+    const accountAddress = account.state === AccountState.Ready ? account.address : undefined;
     return {
+        accountAddress,
         buyOrderProcessingState: state.buyOrderState.processState,
         assetBuyer,
         buyQuote: state.latestBuyQuote,
diff --git a/packages/instant/src/redux/actions.ts b/packages/instant/src/redux/actions.ts
index c41c5054bf..084360629b 100644
--- a/packages/instant/src/redux/actions.ts
+++ b/packages/instant/src/redux/actions.ts
@@ -21,6 +21,10 @@ function createAction<T extends string, P>(type: T, data?: P): PlainAction<T> |
 }
 
 export enum ActionTypes {
+    SET_ACCOUNT_STATE_LOADING = 'SET_ACCOUNT_STATE_LOADING',
+    SET_ACCOUNT_STATE_LOCKED = 'SET_ACCOUNT_STATE_LOCKED',
+    SET_ACCOUNT_STATE_ERROR = 'SET_ACCOUNT_STATE_ERROR',
+    SET_ACCOUNT_STATE_READY = 'SET_ACCOUNT_STATE_READY',
     UPDATE_ETH_USD_PRICE = 'UPDATE_ETH_USD_PRICE',
     UPDATE_SELECTED_ASSET_AMOUNT = 'UPDATE_SELECTED_ASSET_AMOUNT',
     SET_BUY_ORDER_STATE_NONE = 'SET_BUY_ORDER_STATE_NONE',
@@ -40,6 +44,10 @@ export enum ActionTypes {
 }
 
 export const actions = {
+    setAccountStateLoading: () => createAction(ActionTypes.SET_ACCOUNT_STATE_LOADING),
+    setAccountStateLocked: () => createAction(ActionTypes.SET_ACCOUNT_STATE_LOCKED),
+    setAccountStateError: () => createAction(ActionTypes.SET_ACCOUNT_STATE_ERROR),
+    setAccountStateReady: (address: string) => createAction(ActionTypes.SET_ACCOUNT_STATE_READY, address),
     updateEthUsdPrice: (price?: BigNumber) => createAction(ActionTypes.UPDATE_ETH_USD_PRICE, price),
     updateSelectedAssetAmount: (amount?: BigNumber) => createAction(ActionTypes.UPDATE_SELECTED_ASSET_AMOUNT, amount),
     setBuyOrderStateNone: () => createAction(ActionTypes.SET_BUY_ORDER_STATE_NONE),
diff --git a/packages/instant/src/redux/async_data.ts b/packages/instant/src/redux/async_data.ts
index c3d190af28..e27ec1dc3f 100644
--- a/packages/instant/src/redux/async_data.ts
+++ b/packages/instant/src/redux/async_data.ts
@@ -1,6 +1,7 @@
 import * as _ from 'lodash';
 
 import { BIG_NUMBER_ZERO } from '../constants';
+import { AccountState } from '../types';
 import { assetUtils } from '../util/asset';
 import { coinbaseApi } from '../util/coinbase_api';
 import { errorFlasher } from '../util/error_flasher';
@@ -33,4 +34,24 @@ export const asyncData = {
             store.dispatch(actions.setAvailableAssets([]));
         }
     },
+    fetchAccountInfoAndDispatchToStore: async (store: Store) => {
+        const { providerState } = store.getState();
+        const web3Wrapper = providerState.web3Wrapper;
+        if (providerState.account.state !== AccountState.Loading) {
+            store.dispatch(actions.setAccountStateLoading());
+        }
+        let availableAddresses: string[];
+        try {
+            availableAddresses = await web3Wrapper.getAvailableAddressesAsync();
+        } catch (e) {
+            store.dispatch(actions.setAccountStateError());
+            return;
+        }
+        if (!_.isEmpty(availableAddresses)) {
+            const activeAddress = availableAddresses[0];
+            store.dispatch(actions.setAccountStateReady(activeAddress));
+        } else {
+            store.dispatch(actions.setAccountStateLocked());
+        }
+    },
 };
diff --git a/packages/instant/src/redux/reducer.ts b/packages/instant/src/redux/reducer.ts
index 4a939839af..9bbd114a2d 100644
--- a/packages/instant/src/redux/reducer.ts
+++ b/packages/instant/src/redux/reducer.ts
@@ -4,8 +4,12 @@ import { BigNumber } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as _ from 'lodash';
 
+import { ERROR_ACCOUNT, LOADING_ACCOUNT, LOCKED_ACCOUNT } from '../constants';
 import { assetMetaDataMap } from '../data/asset_meta_data_map';
 import {
+    Account,
+    AccountReady,
+    AccountState,
     AffiliateInfo,
     Asset,
     AssetMetaData,
@@ -57,6 +61,18 @@ export const DEFAULT_STATE: DefaultState = {
 export const createReducer = (initialState: State) => {
     const reducer = (state: State = initialState, action: Action): State => {
         switch (action.type) {
+            case ActionTypes.SET_ACCOUNT_STATE_LOADING:
+                return reduceStateWithAccount(state, LOADING_ACCOUNT);
+            case ActionTypes.SET_ACCOUNT_STATE_LOCKED:
+                return reduceStateWithAccount(state, LOCKED_ACCOUNT);
+            case ActionTypes.SET_ACCOUNT_STATE_ERROR:
+                return reduceStateWithAccount(state, ERROR_ACCOUNT);
+            case ActionTypes.SET_ACCOUNT_STATE_READY:
+                const account: AccountReady = {
+                    state: AccountState.Ready,
+                    address: action.data,
+                };
+                return reduceStateWithAccount(state, account);
             case ActionTypes.UPDATE_ETH_USD_PRICE:
                 return {
                     ...state,
@@ -80,7 +96,6 @@ export const createReducer = (initialState: State) => {
                 } else {
                     return state;
                 }
-
             case ActionTypes.SET_QUOTE_REQUEST_STATE_PENDING:
                 return {
                     ...state,
@@ -191,6 +206,18 @@ export const createReducer = (initialState: State) => {
     return reducer;
 };
 
+const reduceStateWithAccount = (state: State, account: Account) => {
+    const oldProviderState = state.providerState;
+    const newProviderState: ProviderState = {
+        ...oldProviderState,
+        account,
+    };
+    return {
+        ...state,
+        providerState: newProviderState,
+    };
+};
+
 const doesBuyQuoteMatchState = (buyQuote: BuyQuote, state: State): boolean => {
     const selectedAssetIfExists = state.selectedAsset;
     const selectedAssetAmountIfExists = state.selectedAssetAmount;
diff --git a/packages/instant/src/util/provider_state_factory.ts b/packages/instant/src/util/provider_state_factory.ts
index 18b188d895..3006c5e141 100644
--- a/packages/instant/src/util/provider_state_factory.ts
+++ b/packages/instant/src/util/provider_state_factory.ts
@@ -2,18 +2,12 @@ import { Web3Wrapper } from '@0x/web3-wrapper';
 import { Provider } from 'ethereum-types';
 import * as _ from 'lodash';
 
+import { LOADING_ACCOUNT, NO_ACCOUNT } from '../constants';
 import { AccountNotReady, AccountState, Maybe, Network, OrderSource, ProviderState } from '../types';
 
 import { assetBuyerFactory } from './asset_buyer_factory';
 import { providerFactory } from './provider_factory';
 
-const LOADING_ACCOUNT: AccountNotReady = {
-    state: AccountState.Loading,
-};
-const NO_ACCOUNT: AccountNotReady = {
-    state: AccountState.None,
-};
-
 export const providerStateFactory = {
     getInitialProviderState: (orderSource: OrderSource, network: Network, provider?: Provider): ProviderState => {
         if (!_.isUndefined(provider)) {

From cde192df0d48bb45f57c319179dbd9f64abd13e9 Mon Sep 17 00:00:00 2001
From: Brandon Millman <brandon.millman@gmail.com>
Date: Wed, 7 Nov 2018 23:36:00 -0800
Subject: [PATCH 2/4] feat(instant): fetch balance at startup

---
 packages/instant/src/components/buy_button.tsx   | 13 +++++++------
 .../src/components/buy_order_state_buttons.tsx   |  6 ++++++
 .../selected_asset_buy_order_state_buttons.ts    |  8 ++++++++
 packages/instant/src/redux/actions.ts            |  2 ++
 packages/instant/src/redux/async_data.ts         | 16 ++++++++++++++++
 packages/instant/src/redux/reducer.ts            | 15 ++++++++++++++-
 packages/instant/src/util/balance.ts             | 13 -------------
 7 files changed, 53 insertions(+), 20 deletions(-)
 delete mode 100644 packages/instant/src/util/balance.ts

diff --git a/packages/instant/src/components/buy_button.tsx b/packages/instant/src/components/buy_button.tsx
index f24bb57eeb..9a6e22ea93 100644
--- a/packages/instant/src/components/buy_button.tsx
+++ b/packages/instant/src/components/buy_button.tsx
@@ -1,4 +1,5 @@
 import { AssetBuyer, AssetBuyerError, BuyQuote } from '@0x/asset-buyer';
+import { BigNumber } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as _ from 'lodash';
 import * as React from 'react';
@@ -7,8 +8,6 @@ import { oc } from 'ts-optchain';
 import { WEB_3_WRAPPER_TRANSACTION_FAILED_ERROR_MSG_PREFIX } from '../constants';
 import { ColorOption } from '../style/theme';
 import { AffiliateInfo, ZeroExInstantError } from '../types';
-import { getBestAddress } from '../util/address';
-import { balanceUtil } from '../util/balance';
 import { gasPriceEstimator } from '../util/gas_price_estimator';
 import { util } from '../util/util';
 
@@ -17,8 +16,10 @@ import { Text } from './ui/text';
 
 export interface BuyButtonProps {
     accountAddress?: string;
+    accountEthBalanceInWei?: BigNumber;
     buyQuote?: BuyQuote;
     assetBuyer: AssetBuyer;
+    web3Wrapper: Web3Wrapper;
     affiliateInfo?: AffiliateInfo;
     onValidationPending: (buyQuote: BuyQuote) => void;
     onValidationFail: (buyQuote: BuyQuote, errorMessage: AssetBuyerError | ZeroExInstantError) => void;
@@ -47,14 +48,14 @@ export class BuyButton extends React.Component<BuyButtonProps> {
     }
     private readonly _handleClick = async () => {
         // The button is disabled when there is no buy quote anyway.
-        const { buyQuote, assetBuyer, affiliateInfo, accountAddress } = this.props;
+        const { buyQuote, assetBuyer, affiliateInfo, accountAddress, accountEthBalanceInWei, web3Wrapper } = this.props;
         if (_.isUndefined(buyQuote) || _.isUndefined(accountAddress)) {
             return;
         }
         this.props.onValidationPending(buyQuote);
-        // TODO(bmillman): move balance fetching to the async state and get rid of web3 wrapper here
-        const web3Wrapper = new Web3Wrapper(assetBuyer.provider);
-        const hasSufficientEth = await balanceUtil.hasSufficientEth(accountAddress, buyQuote, web3Wrapper);
+        const ethNeededForBuy = buyQuote.worstCaseQuoteInfo.totalEthAmount;
+        // if we don't have a balance for the user, let the transaction through, it will be handled by the wallet
+        const hasSufficientEth = _.isUndefined(accountEthBalanceInWei) || accountEthBalanceInWei.gte(ethNeededForBuy);
         if (!hasSufficientEth) {
             this.props.onValidationFail(buyQuote, ZeroExInstantError.InsufficientETH);
             return;
diff --git a/packages/instant/src/components/buy_order_state_buttons.tsx b/packages/instant/src/components/buy_order_state_buttons.tsx
index b15415e719..b46ff77140 100644
--- a/packages/instant/src/components/buy_order_state_buttons.tsx
+++ b/packages/instant/src/components/buy_order_state_buttons.tsx
@@ -1,4 +1,6 @@
 import { AssetBuyer, AssetBuyerError, BuyQuote } from '@0x/asset-buyer';
+import { BigNumber } from '@0x/utils';
+import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as React from 'react';
 
 import { ColorOption } from '../style/theme';
@@ -14,9 +16,11 @@ import { Text } from './ui/text';
 
 export interface BuyOrderStateButtonProps {
     accountAddress?: string;
+    accountEthBalanceInWei?: BigNumber;
     buyQuote?: BuyQuote;
     buyOrderProcessingState: OrderProcessState;
     assetBuyer: AssetBuyer;
+    web3Wrapper: Web3Wrapper;
     affiliateInfo?: AffiliateInfo;
     onViewTransaction: () => void;
     onValidationPending: (buyQuote: BuyQuote) => void;
@@ -54,8 +58,10 @@ export const BuyOrderStateButtons: React.StatelessComponent<BuyOrderStateButtonP
     return (
         <BuyButton
             accountAddress={props.accountAddress}
+            accountEthBalanceInWei={props.accountEthBalanceInWei}
             buyQuote={props.buyQuote}
             assetBuyer={props.assetBuyer}
+            web3Wrapper={props.web3Wrapper}
             affiliateInfo={props.affiliateInfo}
             onValidationPending={props.onValidationPending}
             onValidationFail={props.onValidationFail}
diff --git a/packages/instant/src/containers/selected_asset_buy_order_state_buttons.ts b/packages/instant/src/containers/selected_asset_buy_order_state_buttons.ts
index 2678d4a369..610335243e 100644
--- a/packages/instant/src/containers/selected_asset_buy_order_state_buttons.ts
+++ b/packages/instant/src/containers/selected_asset_buy_order_state_buttons.ts
@@ -1,4 +1,6 @@
 import { AssetBuyer, AssetBuyerError, BuyQuote } from '@0x/asset-buyer';
+import { BigNumber } from '@0x/utils';
+import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as _ from 'lodash';
 import * as React from 'react';
 import { connect } from 'react-redux';
@@ -13,9 +15,11 @@ import { etherscanUtil } from '../util/etherscan';
 
 interface ConnectedState {
     accountAddress?: string;
+    accountEthBalanceInWei?: BigNumber;
     buyQuote?: BuyQuote;
     buyOrderProcessingState: OrderProcessState;
     assetBuyer: AssetBuyer;
+    web3Wrapper: Web3Wrapper;
     affiliateInfo?: AffiliateInfo;
     onViewTransaction: () => void;
 }
@@ -32,12 +36,16 @@ interface ConnectedDispatch {
 export interface SelectedAssetBuyOrderStateButtons {}
 const mapStateToProps = (state: State, _ownProps: SelectedAssetBuyOrderStateButtons): ConnectedState => {
     const assetBuyer = state.providerState.assetBuyer;
+    const web3Wrapper = state.providerState.web3Wrapper;
     const account = state.providerState.account;
     const accountAddress = account.state === AccountState.Ready ? account.address : undefined;
+    const accountEthBalanceInWei = account.state === AccountState.Ready ? account.ethBalanceInWei : undefined;
     return {
         accountAddress,
+        accountEthBalanceInWei,
         buyOrderProcessingState: state.buyOrderState.processState,
         assetBuyer,
+        web3Wrapper,
         buyQuote: state.latestBuyQuote,
         affiliateInfo: state.affiliateInfo,
         onViewTransaction: () => {
diff --git a/packages/instant/src/redux/actions.ts b/packages/instant/src/redux/actions.ts
index 084360629b..9b0d80152d 100644
--- a/packages/instant/src/redux/actions.ts
+++ b/packages/instant/src/redux/actions.ts
@@ -25,6 +25,7 @@ export enum ActionTypes {
     SET_ACCOUNT_STATE_LOCKED = 'SET_ACCOUNT_STATE_LOCKED',
     SET_ACCOUNT_STATE_ERROR = 'SET_ACCOUNT_STATE_ERROR',
     SET_ACCOUNT_STATE_READY = 'SET_ACCOUNT_STATE_READY',
+    UPDATE_ACCOUNT_ETH_BALANCE = 'UPDATE_ACCOUNT_ETH_BALANCE',
     UPDATE_ETH_USD_PRICE = 'UPDATE_ETH_USD_PRICE',
     UPDATE_SELECTED_ASSET_AMOUNT = 'UPDATE_SELECTED_ASSET_AMOUNT',
     SET_BUY_ORDER_STATE_NONE = 'SET_BUY_ORDER_STATE_NONE',
@@ -48,6 +49,7 @@ export const actions = {
     setAccountStateLocked: () => createAction(ActionTypes.SET_ACCOUNT_STATE_LOCKED),
     setAccountStateError: () => createAction(ActionTypes.SET_ACCOUNT_STATE_ERROR),
     setAccountStateReady: (address: string) => createAction(ActionTypes.SET_ACCOUNT_STATE_READY, address),
+    updateAccountEthBalance: (balance: BigNumber) => createAction(ActionTypes.UPDATE_ACCOUNT_ETH_BALANCE, balance),
     updateEthUsdPrice: (price?: BigNumber) => createAction(ActionTypes.UPDATE_ETH_USD_PRICE, price),
     updateSelectedAssetAmount: (amount?: BigNumber) => createAction(ActionTypes.UPDATE_SELECTED_ASSET_AMOUNT, amount),
     setBuyOrderStateNone: () => createAction(ActionTypes.SET_BUY_ORDER_STATE_NONE),
diff --git a/packages/instant/src/redux/async_data.ts b/packages/instant/src/redux/async_data.ts
index e27ec1dc3f..862f60e78b 100644
--- a/packages/instant/src/redux/async_data.ts
+++ b/packages/instant/src/redux/async_data.ts
@@ -50,8 +50,24 @@ export const asyncData = {
         if (!_.isEmpty(availableAddresses)) {
             const activeAddress = availableAddresses[0];
             store.dispatch(actions.setAccountStateReady(activeAddress));
+            await asyncData.fetchAccountBalanceAndDispatchToStore(store);
         } else {
             store.dispatch(actions.setAccountStateLocked());
         }
     },
+    fetchAccountBalanceAndDispatchToStore: async (store: Store) => {
+        const { providerState } = store.getState();
+        const web3Wrapper = providerState.web3Wrapper;
+        const account = providerState.account;
+        if (account.state !== AccountState.Ready) {
+            return;
+        }
+        try {
+            const ethBalanceInWei = await web3Wrapper.getBalanceInWeiAsync(account.address);
+            store.dispatch(actions.updateAccountEthBalance(ethBalanceInWei));
+        } catch (e) {
+            // leave balance as is
+            return;
+        }
+    },
 };
diff --git a/packages/instant/src/redux/reducer.ts b/packages/instant/src/redux/reducer.ts
index 9bbd114a2d..961e296198 100644
--- a/packages/instant/src/redux/reducer.ts
+++ b/packages/instant/src/redux/reducer.ts
@@ -67,12 +67,25 @@ export const createReducer = (initialState: State) => {
                 return reduceStateWithAccount(state, LOCKED_ACCOUNT);
             case ActionTypes.SET_ACCOUNT_STATE_ERROR:
                 return reduceStateWithAccount(state, ERROR_ACCOUNT);
-            case ActionTypes.SET_ACCOUNT_STATE_READY:
+            case ActionTypes.SET_ACCOUNT_STATE_READY: {
                 const account: AccountReady = {
                     state: AccountState.Ready,
                     address: action.data,
                 };
                 return reduceStateWithAccount(state, account);
+            }
+            case ActionTypes.UPDATE_ACCOUNT_ETH_BALANCE: {
+                const account = state.providerState.account;
+                if (account.state !== AccountState.Ready) {
+                    return state;
+                } else {
+                    const newAccount: AccountReady = {
+                        ...account,
+                        ethBalanceInWei: action.data,
+                    };
+                    return reduceStateWithAccount(state, newAccount);
+                }
+            }
             case ActionTypes.UPDATE_ETH_USD_PRICE:
                 return {
                     ...state,
diff --git a/packages/instant/src/util/balance.ts b/packages/instant/src/util/balance.ts
deleted file mode 100644
index f2271495b9..0000000000
--- a/packages/instant/src/util/balance.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-import { BuyQuote } from '@0x/asset-buyer';
-import { Web3Wrapper } from '@0x/web3-wrapper';
-import * as _ from 'lodash';
-
-export const balanceUtil = {
-    hasSufficientEth: async (takerAddress: string | undefined, buyQuote: BuyQuote, web3Wrapper: Web3Wrapper) => {
-        if (_.isUndefined(takerAddress)) {
-            return false;
-        }
-        const balanceWei = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
-        return balanceWei.gte(buyQuote.worstCaseQuoteInfo.totalEthAmount);
-    },
-};

From c84e163edb329b478749cad09f222cc12e3698fe Mon Sep 17 00:00:00 2001
From: Brandon Millman <brandon.millman@gmail.com>
Date: Wed, 7 Nov 2018 23:43:37 -0800
Subject: [PATCH 3/4] chore(instant): fix lint errors

---
 packages/instant/src/util/provider_state_factory.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/instant/src/util/provider_state_factory.ts b/packages/instant/src/util/provider_state_factory.ts
index 3006c5e141..3281f6bfba 100644
--- a/packages/instant/src/util/provider_state_factory.ts
+++ b/packages/instant/src/util/provider_state_factory.ts
@@ -3,7 +3,7 @@ import { Provider } from 'ethereum-types';
 import * as _ from 'lodash';
 
 import { LOADING_ACCOUNT, NO_ACCOUNT } from '../constants';
-import { AccountNotReady, AccountState, Maybe, Network, OrderSource, ProviderState } from '../types';
+import { Maybe, Network, OrderSource, ProviderState } from '../types';
 
 import { assetBuyerFactory } from './asset_buyer_factory';
 import { providerFactory } from './provider_factory';

From b147cd888505443981781d200a68b949812cb3e9 Mon Sep 17 00:00:00 2001
From: Brandon Millman <brandon.millman@gmail.com>
Date: Thu, 8 Nov 2018 17:22:21 -0800
Subject: [PATCH 4/4] fix(instant): fix bug where we potentially fetch balance
 for the wrong account

---
 packages/instant/src/redux/actions.ts    | 5 +++--
 packages/instant/src/redux/async_data.ts | 8 +++++---
 packages/instant/src/redux/reducer.ts    | 9 +++++----
 packages/instant/src/types.ts            | 5 +++++
 4 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/packages/instant/src/redux/actions.ts b/packages/instant/src/redux/actions.ts
index 9b0d80152d..fc89e3d0ee 100644
--- a/packages/instant/src/redux/actions.ts
+++ b/packages/instant/src/redux/actions.ts
@@ -2,7 +2,7 @@ import { BuyQuote } from '@0x/asset-buyer';
 import { BigNumber } from '@0x/utils';
 import * as _ from 'lodash';
 
-import { ActionsUnion, Asset } from '../types';
+import { ActionsUnion, AddressAndEthBalanceInWei, Asset } from '../types';
 
 export interface PlainAction<T extends string> {
     type: T;
@@ -49,7 +49,8 @@ export const actions = {
     setAccountStateLocked: () => createAction(ActionTypes.SET_ACCOUNT_STATE_LOCKED),
     setAccountStateError: () => createAction(ActionTypes.SET_ACCOUNT_STATE_ERROR),
     setAccountStateReady: (address: string) => createAction(ActionTypes.SET_ACCOUNT_STATE_READY, address),
-    updateAccountEthBalance: (balance: BigNumber) => createAction(ActionTypes.UPDATE_ACCOUNT_ETH_BALANCE, balance),
+    updateAccountEthBalance: (addressAndBalance: AddressAndEthBalanceInWei) =>
+        createAction(ActionTypes.UPDATE_ACCOUNT_ETH_BALANCE, addressAndBalance),
     updateEthUsdPrice: (price?: BigNumber) => createAction(ActionTypes.UPDATE_ETH_USD_PRICE, price),
     updateSelectedAssetAmount: (amount?: BigNumber) => createAction(ActionTypes.UPDATE_SELECTED_ASSET_AMOUNT, amount),
     setBuyOrderStateNone: () => createAction(ActionTypes.SET_BUY_ORDER_STATE_NONE),
diff --git a/packages/instant/src/redux/async_data.ts b/packages/instant/src/redux/async_data.ts
index bff9d88147..a8f6320097 100644
--- a/packages/instant/src/redux/async_data.ts
+++ b/packages/instant/src/redux/async_data.ts
@@ -52,7 +52,8 @@ export const asyncData = {
         if (!_.isEmpty(availableAddresses)) {
             const activeAddress = availableAddresses[0];
             store.dispatch(actions.setAccountStateReady(activeAddress));
-            await asyncData.fetchAccountBalanceAndDispatchToStore(store);
+            // tslint:disable-next-line:no-floating-promises
+            asyncData.fetchAccountBalanceAndDispatchToStore(store);
         } else {
             store.dispatch(actions.setAccountStateLocked());
         }
@@ -65,8 +66,9 @@ export const asyncData = {
             return;
         }
         try {
-            const ethBalanceInWei = await web3Wrapper.getBalanceInWeiAsync(account.address);
-            store.dispatch(actions.updateAccountEthBalance(ethBalanceInWei));
+            const address = account.address;
+            const ethBalanceInWei = await web3Wrapper.getBalanceInWeiAsync(address);
+            store.dispatch(actions.updateAccountEthBalance({ address, ethBalanceInWei }));
         } catch (e) {
             // leave balance as is
             return;
diff --git a/packages/instant/src/redux/reducer.ts b/packages/instant/src/redux/reducer.ts
index 961e296198..a5a1b6f7d7 100644
--- a/packages/instant/src/redux/reducer.ts
+++ b/packages/instant/src/redux/reducer.ts
@@ -75,13 +75,14 @@ export const createReducer = (initialState: State) => {
                 return reduceStateWithAccount(state, account);
             }
             case ActionTypes.UPDATE_ACCOUNT_ETH_BALANCE: {
-                const account = state.providerState.account;
-                if (account.state !== AccountState.Ready) {
+                const { address, ethBalanceInWei } = action.data;
+                const currentAccount = state.providerState.account;
+                if (currentAccount.state !== AccountState.Ready || currentAccount.address !== address) {
                     return state;
                 } else {
                     const newAccount: AccountReady = {
-                        ...account,
-                        ethBalanceInWei: action.data,
+                        ...currentAccount,
+                        ethBalanceInWei,
                     };
                     return reduceStateWithAccount(state, newAccount);
                 }
diff --git a/packages/instant/src/types.ts b/packages/instant/src/types.ts
index d65f700081..20ad2ed955 100644
--- a/packages/instant/src/types.ts
+++ b/packages/instant/src/types.ts
@@ -120,3 +120,8 @@ export interface AccountNotReady {
 export type Account = AccountReady | AccountNotReady;
 
 export type OrderSource = string | SignedOrder[];
+
+export interface AddressAndEthBalanceInWei {
+    address: string;
+    ethBalanceInWei: BigNumber;
+}