1 files changed, 30 insertions, 0 deletions
diff --git a/packages/contracts/src/utils/balances.ts b/packages/contracts/src/utils/balances.ts
new file mode 100644
index 000000000..2ebc10313
--- /dev/null
+++ b/packages/contracts/src/utils/balances.ts
@@ -0,0 +1,30 @@
+import { BigNumber } from '@0xproject/utils';
+import * as _ from 'lodash';
+import * as Web3 from 'web3';
+
+import { DummyTokenContract } from '../contract_wrappers/generated/dummy_token';
+
+import { BalancesByOwner } from './types';
+
+export class Balances {
+    private _tokenContractInstances: DummyTokenContract[];
+    private _ownerAddresses: string[];
+    constructor(tokenContractInstances: DummyTokenContract[], 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.callAsync(ownerAddress);
+                balance = new BigNumber(balance);
+                if (_.isUndefined(balancesByOwner[ownerAddress])) {
+                    balancesByOwner[ownerAddress] = {};
+                }
+                balancesByOwner[ownerAddress][tokenContractInstance.address] = balance;
+            }
+        }
+        return balancesByOwner;
+    }
+}