fix(instant): fix bug where we potentially fetch balance for the wrong account

4 files changed, 18 insertions, 9 deletions

diff --git a/packages/instant/src/redux/actions.ts b/packages/instant/src/redux/actions.ts
index 9b0d80152..fc89e3d0e 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 bff9d8814..a8f632009 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 961e29619..a5a1b6f7d 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 d65f70008..20ad2ed95 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;
+}