Validate enough ETH when user clicks buy

packages/instant/src/components/buy_button.tsx

@@ -5,6 +5,7 @@ import * as React from 'react';
 import { WEB_3_WRAPPER_TRANSACTION_FAILED_ERROR_MSG_PREFIX } from '../constants';
 import { ColorOption } from '../style/theme';
 import { getBestAddress } from '../util/address';
+import { balanceUtil } from '../util/balance';
 import { util } from '../util/util';
 import { web3Wrapper } from '../util/web3_wrapper';
 
@@ -18,6 +19,7 @@ export interface BuyButtonProps {
     onBuyProcessing: (buyQuote: BuyQuote, txHash: string) => void;
     onBuySuccess: (buyQuote: BuyQuote, txHash: string) => void;
     onBuyFailure: (buyQuote: BuyQuote, txHash: string) => void;
+    validateWalletBeforeBuy: (buyQuote: BuyQuote, takerAddress: string | undefined) => Promise<boolean>;
 }
 
 export class BuyButton extends React.Component<BuyButtonProps> {
@@ -43,10 +45,15 @@ export class BuyButton extends React.Component<BuyButtonProps> {
             return;
         }
 
+        const takerAddress = await getBestAddress();
+        const validWallet = await this.props.validateWalletBeforeBuy(buyQuote, takerAddress);
+        if (!validWallet) {
+            return;
+        }
+
         let txHash: string | undefined;
         this.props.onAwaitingSignature(buyQuote);
         try {
-            const takerAddress = await getBestAddress();
             txHash = await assetBuyer.executeBuyQuoteAsync(buyQuote, { takerAddress });
         } catch (e) {
             if (e instanceof Error && e.message === AssetBuyerError.SignatureRequestDenied) {

packages/instant/src/components/buy_order_state_buttons.tsx

@@ -23,6 +23,7 @@ export interface BuyOrderStateButtonProps {
     onBuySuccess: (buyQuote: BuyQuote, txHash: string) => void;
     onBuyFailure: (buyQuote: BuyQuote, txHash: string) => void;
     onRetry: () => void;
+    validateWalletBeforeBuy: (buyQuote: BuyQuote, takerAddress: string | undefined) => Promise<boolean>;
 }
 
 // TODO: rename to buttons
@@ -58,6 +59,7 @@ export const BuyOrderStateButtons: React.StatelessComponent<BuyOrderStateButtonP
             onBuyProcessing={props.onBuyProcessing}
             onBuySuccess={props.onBuySuccess}
             onBuyFailure={props.onBuyFailure}
+            validateWalletBeforeBuy={props.validateWalletBeforeBuy}
         />
     );
 };

packages/instant/src/containers/selected_asset_buy_order_state_buttons.ts

@@ -7,7 +7,9 @@ import { Dispatch } from 'redux';
 import { Action, actions } from '../redux/actions';
 import { State } from '../redux/reducer';
 import { OrderProcessState, OrderState } from '../types';
+import { balanceUtil } from '../util/balance';
 import { etherscanUtil } from '../util/etherscan';
+import { web3Wrapper } from '../util/web3_wrapper';
 
 import { BuyOrderStateButtons } from '../components/buy_order_state_buttons';
 
@@ -25,6 +27,7 @@ interface ConnectedDispatch {
     onBuySuccess: (buyQuote: BuyQuote, txHash: string) => void;
     onBuyFailure: (buyQuote: BuyQuote, txHash: string) => void;
     onRetry: () => void;
+    validateWalletBeforeBuy: (buyQuote: BuyQuote, takerAddress: string | undefined) => Promise<boolean>;
 }
 export interface SelectedAssetBuyOrderStateButtons {}
 const mapStateToProps = (state: State, _ownProps: SelectedAssetBuyOrderStateButtons): ConnectedState => ({
@@ -73,6 +76,9 @@ const mapDispatchToProps = (
     onRetry: () => {
         dispatch(actions.resetAmount());
     },
+    validateWalletBeforeBuy: async (buyQuote: BuyQuote, takerAddress: string | undefined) => {
+        return balanceUtil.checkInsufficientEthBalanceAndFlashError(takerAddress, buyQuote, web3Wrapper, dispatch);
+    },
 });
 
 export const SelectedAssetBuyOrderStateButtons: React.ComponentClass<SelectedAssetBuyOrderStateButtons> = connect(