1 files changed, 30 insertions, 0 deletions
diff --git a/packages/contracts/util/balances.ts b/packages/contracts/util/balances.ts
new file mode 100644
index 000000000..fce15db6d
--- /dev/null
+++ b/packages/contracts/util/balances.ts
@@ -0,0 +1,30 @@
+import {BigNumber} from 'bignumber.js';
+import * as _ from 'lodash';
+
+import {bigNumberConfigs} from './bignumber_config';
+import {BalancesByOwner, ContractInstance} from './types';
+
+bigNumberConfigs.configure();
+
+export class Balances {
+    private tokenContractInstances: ContractInstance[];
+    private ownerAddresses: string[];
+    constructor(tokenContractInstances: ContractInstance[], ownerAddresses: string[]) {
+        this.tokenContractInstances = tokenContractInstances;
+        this.ownerAddresses = ownerAddresses;
+    }
+    public async getAsync(): Promise<BalancesByOwner> {
+        const balancesByOwner: BalancesByOwner = {};
+        for (const tokenContractInstance of this.tokenContractInstances) {
+            for (const ownerAddress of this.ownerAddresses) {
+                let balance = await tokenContractInstance.balanceOf(ownerAddress);
+                balance = new BigNumber(balance);
+                if (_.isUndefined(balancesByOwner[ownerAddress])) {
+                    balancesByOwner[ownerAddress] = {};
+                }
+                balancesByOwner[ownerAddress][tokenContractInstance.address] = balance;
+            }
+        }
+        return balancesByOwner;
+    }
+}