Add a test that unlimited allowance reduces gas cost

1 files changed, 28 insertions, 0 deletions

diff --git a/test/token_wrapper_test.ts b/test/token_wrapper_test.ts
index e466cc0ad..22e1ff12d 100644
--- a/test/token_wrapper_test.ts
+++ b/test/token_wrapper_test.ts
@@ -16,6 +16,7 @@ import {
     ApprovalContractEventArgs,
 } from '../src';
 import {BlockchainLifecycle} from './utils/blockchain_lifecycle';
+import {TokenUtils} from './utils/token_utils';
 import {DoneCallback} from '../src/types';
 
 chaiSetup.configure();
@@ -27,6 +28,7 @@ describe('TokenWrapper', () => {
     let zeroEx: ZeroEx;
     let userAddresses: string[];
     let tokens: Token[];
+    let tokenUtils: TokenUtils;
     let coinbase: string;
     let addressWithoutFunds: string;
     before(async () => {
@@ -34,6 +36,7 @@ describe('TokenWrapper', () => {
         zeroEx = new ZeroEx(web3.currentProvider);
         userAddresses = await promisify(web3.eth.getAccounts)();
         tokens = await zeroEx.tokenRegistry.getTokensAsync();
+        tokenUtils = new TokenUtils(tokens);
         coinbase = userAddresses[0];
         addressWithoutFunds = userAddresses[1];
     });
@@ -216,6 +219,31 @@ describe('TokenWrapper', () => {
             const allowance = await zeroEx.token.getAllowanceAsync(token.address, ownerAddress, spenderAddress);
             return expect(allowance).to.be.bignumber.equal(zeroEx.token.UNLIMITED_ALLOWANCE_IN_BASE_UNITS);
         });
+        it('should reduce the gas cost for transfers including tokens with unlimited allowance support', async () => {
+            const transferAmount = new BigNumber(5);
+            const zrx = tokenUtils.getProtocolTokenOrThrow();
+            const [, userWithNormalAllowance, userWithUnlimitedAllowance] = userAddresses;
+            await zeroEx.token.setAllowanceAsync(zrx.address, coinbase, userWithNormalAllowance, transferAmount);
+            await zeroEx.token.setUnlimitedAllowanceAsync(zrx.address, coinbase, userWithUnlimitedAllowance);
+
+            const initBalanceWithNormalAllowance = await promisify(web3.eth.getBalance)(userWithNormalAllowance);
+            const initBalanceWithUnlimitedAllowance = await promisify(web3.eth.getBalance)(userWithUnlimitedAllowance);
+
+            await zeroEx.token.transferFromAsync(
+                zrx.address, coinbase, userWithNormalAllowance, userWithNormalAllowance, transferAmount,
+            );
+            await zeroEx.token.transferFromAsync(
+                zrx.address, coinbase, userWithUnlimitedAllowance, userWithUnlimitedAllowance, transferAmount,
+            );
+
+            const finalBalanceWithNormalAllowance = await promisify(web3.eth.getBalance)(userWithNormalAllowance);
+            const finalBalanceWithUnlimitedAllowance = await promisify(web3.eth.getBalance)(userWithUnlimitedAllowance);
+
+            const normalGasCost = initBalanceWithNormalAllowance.minus(finalBalanceWithNormalAllowance);
+            const unlimitedGasCost = initBalanceWithUnlimitedAllowance.minus(finalBalanceWithUnlimitedAllowance);
+
+            expect(normalGasCost.toNumber()).to.be.gt(unlimitedGasCost.toNumber());
+        });
     });
     describe('#getAllowanceAsync', () => {
         describe('With web3 provider with accounts', () => {