Merge pull request #29 from 0xProject/remainingTokenMethods

Implement Remaining Token Methods

6 files changed, 240 insertions, 48 deletions

diff --git a/src/contract_wrappers/token_wrapper.ts b/src/contract_wrappers/token_wrapper.ts
index 69bcc9024..c8b557d0d 100644
--- a/src/contract_wrappers/token_wrapper.ts
+++ b/src/contract_wrappers/token_wrapper.ts
@@ -33,21 +33,52 @@ export class TokenWrapper extends ContractWrapper {
         return balance;
     }
     /**
-     * Retrieves the allowance in baseUnits of the ERC20 token set to the 0x proxy contract
-     * by an owner address.
+     * Sets the spender's allowance to a specified number of baseUnits on behalf of the owner address.
+     * Equivalent to the ERC20 spec method `approve`.
      */
-    public async getProxyAllowanceAsync(tokenAddress: string, ownerAddress: string) {
+    public async setAllowanceAsync(tokenAddress: string, ownerAddress: string, spenderAddress: string,
+                                   amountInBaseUnits: BigNumber.BigNumber): Promise<void> {
         assert.isETHAddressHex('ownerAddress', ownerAddress);
+        assert.isETHAddressHex('spenderAddress', spenderAddress);
         assert.isETHAddressHex('tokenAddress', tokenAddress);
+        assert.isBigNumber('amountInBaseUnits', amountInBaseUnits);
 
         const tokenContract = await this.getTokenContractAsync(tokenAddress);
-        const proxyAddress = await this.getProxyAddressAsync();
-        let allowanceInBaseUnits = await tokenContract.allowance.call(ownerAddress, proxyAddress);
+        // Hack: for some reason default estimated gas amount causes `base fee exceeds gas limit` exception
+        // on testrpc. Probably related to https://github.com/ethereumjs/testrpc/issues/294
+        // TODO: Debug issue in testrpc and submit a PR, then remove this hack
+        const networkIdIfExists = await this.web3Wrapper.getNetworkIdIfExistsAsync();
+        const gas = networkIdIfExists === constants.TESTRPC_NETWORK_ID ? ALLOWANCE_TO_ZERO_GAS_AMOUNT : undefined;
+        await tokenContract.approve(spenderAddress, amountInBaseUnits, {
+            from: ownerAddress,
+            gas,
+        });
+    }
+    /**
+     * Retrieves the owners allowance in baseUnits set to the spender's address.
+     */
+    public async getAllowanceAsync(tokenAddress: string, ownerAddress: string, spenderAddress: string) {
+        assert.isETHAddressHex('ownerAddress', ownerAddress);
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+
+        const tokenContract = await this.getTokenContractAsync(tokenAddress);
+        let allowanceInBaseUnits = await tokenContract.allowance.call(ownerAddress, spenderAddress);
         // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
         allowanceInBaseUnits = new BigNumber(allowanceInBaseUnits);
         return allowanceInBaseUnits;
     }
     /**
+     * Retrieves the owner's allowance in baseUnits set to the 0x proxy contract.
+     */
+    public async getProxyAllowanceAsync(tokenAddress: string, ownerAddress: string) {
+        assert.isETHAddressHex('ownerAddress', ownerAddress);
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+
+        const proxyAddress = await this.getProxyAddressAsync();
+        const allowanceInBaseUnits = await this.getAllowanceAsync(tokenAddress, ownerAddress, proxyAddress);
+        return allowanceInBaseUnits;
+    }
+    /**
      * Sets the 0x proxy contract's allowance to a specified number of a tokens' baseUnits on behalf
      * of an owner address.
      */
@@ -57,17 +88,8 @@ export class TokenWrapper extends ContractWrapper {
         assert.isETHAddressHex('tokenAddress', tokenAddress);
         assert.isBigNumber('amountInBaseUnits', amountInBaseUnits);
 
-        const tokenContract = await this.getTokenContractAsync(tokenAddress);
         const proxyAddress = await this.getProxyAddressAsync();
-        // Hack: for some reason default estimated gas amount causes `base fee exceeds gas limit` exception
-        // on testrpc. Probably related to https://github.com/ethereumjs/testrpc/issues/294
-        // TODO: Debug issue in testrpc and submit a PR, then remove this hack
-        const networkIdIfExists = await this.web3Wrapper.getNetworkIdIfExistsAsync();
-        const gas = networkIdIfExists === constants.TESTRPC_NETWORK_ID ? ALLOWANCE_TO_ZERO_GAS_AMOUNT : undefined;
-        await tokenContract.approve(proxyAddress, amountInBaseUnits, {
-            from: ownerAddress,
-            gas,
-        });
+        await this.setAllowanceAsync(tokenAddress, ownerAddress, proxyAddress, amountInBaseUnits);
     }
     /**
      * Transfers `amountInBaseUnits` ERC20 tokens from `fromAddress` to `toAddress`.
@@ -80,10 +102,47 @@ export class TokenWrapper extends ContractWrapper {
         assert.isBigNumber('amountInBaseUnits', amountInBaseUnits);
 
         const tokenContract = await this.getTokenContractAsync(tokenAddress);
+
+        const fromAddressBalance = await this.getBalanceAsync(tokenAddress, fromAddress);
+        if (fromAddressBalance.lessThan(amountInBaseUnits)) {
+            throw new Error(ZeroExError.INSUFFICIENT_BALANCE_FOR_TRANSFER);
+        }
+
         await tokenContract.transfer(toAddress, amountInBaseUnits, {
             from: fromAddress,
         });
     }
+    /**
+     * Transfers `amountInBaseUnits` ERC20 tokens from `fromAddress` to `toAddress`.
+     * Requires the fromAddress to have sufficient funds and to have approved an allowance of
+     * `amountInBaseUnits` for senderAddress.
+     */
+    public async transferFromAsync(tokenAddress: string, fromAddress: string, toAddress: string,
+                                   senderAddress: string, amountInBaseUnits: BigNumber.BigNumber):
+                                   Promise<void> {
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        assert.isETHAddressHex('fromAddress', fromAddress);
+        assert.isETHAddressHex('toAddress', toAddress);
+        assert.isETHAddressHex('senderAddress', senderAddress);
+        assert.isBigNumber('amountInBaseUnits', amountInBaseUnits);
+        await assert.isSenderAddressAvailableAsync(this.web3Wrapper, senderAddress);
+
+        const tokenContract = await this.getTokenContractAsync(tokenAddress);
+
+        const fromAddressAllowance = await this.getAllowanceAsync(tokenAddress, fromAddress, senderAddress);
+        if (fromAddressAllowance.lessThan(amountInBaseUnits)) {
+            throw new Error(ZeroExError.INSUFFICIENT_ALLOWANCE_FOR_TRANSFER);
+        }
+
+        const fromAddressBalance = await this.getBalanceAsync(tokenAddress, fromAddress);
+        if (fromAddressBalance.lessThan(amountInBaseUnits)) {
+            throw new Error(ZeroExError.INSUFFICIENT_BALANCE_FOR_TRANSFER);
+        }
+
+        await tokenContract.transferFrom(fromAddress, toAddress, amountInBaseUnits, {
+            from: senderAddress,
+        });
+    }
     private async getTokenContractAsync(tokenAddress: string): Promise<TokenContract> {
         let tokenContract = this.tokenContractsByAddress[tokenAddress];
         if (!_.isUndefined(tokenContract)) {
diff --git a/src/globals.d.ts b/src/globals.d.ts
index d86f54dfc..164fc2386 100644
--- a/src/globals.d.ts
+++ b/src/globals.d.ts
@@ -14,6 +14,12 @@ declare interface Schema {
 // disallow `namespace`, we disable tslint for the following.
 /* tslint:disable */
 declare namespace Chai {
+    interface NumberComparer {
+        (value: number|BigNumber.BigNumber, message?: string): Assertion;
+    }
+    interface NumericComparison {
+        greaterThan: NumberComparer;
+    }
     interface Assertion {
         bignumber: Assertion;
         // HACK: In order to comply with chai-as-promised we make eventually a `PromisedAssertion` not an `Assertion`
diff --git a/src/types.ts b/src/types.ts
index 46156b155..9d3127325 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -16,6 +16,8 @@ export const ZeroExError = strEnum([
     'INVALID_SIGNATURE',
     'CONTRACT_NOT_DEPLOYED_ON_NETWORK',
     'ZRX_NOT_IN_TOKEN_REGISTRY',
+    'INSUFFICIENT_ALLOWANCE_FOR_TRANSFER',
+    'INSUFFICIENT_BALANCE_FOR_TRANSFER',
 ]);
 export type ZeroExError = keyof typeof ZeroExError;
 
@@ -66,7 +68,9 @@ export interface TokenContract {
     allowance: {
         call: (ownerAddress: string, allowedAddress: string) => Promise<BigNumber.BigNumber>;
     };
-    transfer: (to: string, amountInBaseUnits: BigNumber.BigNumber, txOpts: TxOpts) => Promise<boolean>;
+    transfer: (toAddress: string, amountInBaseUnits: BigNumber.BigNumber, txOpts: TxOpts) => Promise<boolean>;
+    transferFrom: (fromAddress: string, toAddress: string, amountInBaseUnits: BigNumber.BigNumber,
+                   txOpts: TxOpts) => Promise<boolean>;
     approve: (proxyAddress: string, amountInBaseUnits: BigNumber.BigNumber, txOpts: TxOpts) => void;
 }
 
diff --git a/src/utils/assert.ts b/src/utils/assert.ts
index 406f2b149..5a31e1b16 100644
--- a/src/utils/assert.ts
+++ b/src/utils/assert.ts
@@ -1,6 +1,7 @@
 import * as _ from 'lodash';
 import * as BigNumber from 'bignumber.js';
 import * as Web3 from 'web3';
+import {Web3Wrapper} from '../web3_wrapper';
 import {SchemaValidator} from './schema_validator';
 import {utils} from './utils';
 
@@ -25,6 +26,11 @@ export const assert = {
         const web3 = new Web3();
         this.assert(web3.isAddress(value), this.typeAssertionMessage(variableName, 'ETHAddressHex', value));
     },
+    async isSenderAddressAvailableAsync(web3Wrapper: Web3Wrapper, senderAddress: string) {
+        const isSenderAddressAvailable = await web3Wrapper.isSenderAddressAvailableAsync(senderAddress);
+        assert.assert(isSenderAddressAvailable, 'Specified senderAddress isn\'t available through the \
+                                                 supplied web3 instance');
+    },
     isNumber(variableName: string, value: number): void {
         this.assert(_.isFinite(value), this.typeAssertionMessage(variableName, 'number', value));
     },
diff --git a/src/web3_wrapper.ts b/src/web3_wrapper.ts
index 49bd8b67d..9892abcb8 100644
--- a/src/web3_wrapper.ts
+++ b/src/web3_wrapper.ts
@@ -29,11 +29,15 @@ export class Web3Wrapper {
         return senderAddressIfExists as string;
     }
     public async getFirstAddressIfExistsAsync(): Promise<string|undefined> {
-        const addresses = await promisify(this.web3.eth.getAccounts)();
+        const addresses = await this.getAvailableSenderAddressesAsync();
         if (_.isEmpty(addresses)) {
             return undefined;
         }
-        return (addresses as string[])[0];
+        return addresses[0];
+    }
+    public async isSenderAddressAvailableAsync(senderAddress: string): Promise<boolean> {
+        const addresses = await this.getAvailableSenderAddressesAsync();
+        return _.includes(addresses, senderAddress);
     }
     public async getNodeVersionAsync(): Promise<string> {
         const nodeVersion = await promisify(this.web3.version.getNode)();
@@ -77,6 +81,10 @@ export class Web3Wrapper {
         const firstAccount = await this.getFirstAddressIfExistsAsync();
         return firstAccount;
     }
+    private async getAvailableSenderAddressesAsync(): Promise<string[]> {
+        const addresses: string[] = await promisify(this.web3.eth.getAccounts)();
+        return addresses;
+    }
     private async getNetworkAsync(): Promise<number> {
         const networkId = await promisify(this.web3.version.getNetwork)();
         return networkId;
diff --git a/test/token_wrapper_test.ts b/test/token_wrapper_test.ts
index cfd87da84..698ad5b6a 100644
--- a/test/token_wrapper_test.ts
+++ b/test/token_wrapper_test.ts
@@ -17,11 +17,15 @@ describe('TokenWrapper', () => {
     let zeroEx: ZeroEx;
     let userAddresses: string[];
     let tokens: Token[];
+    let coinbase: string;
+    let addressWithoutFunds: string;
     before(async () => {
         web3 = web3Factory.create();
         zeroEx = new ZeroEx(web3);
         userAddresses = await promisify(web3.eth.getAccounts)();
         tokens = await zeroEx.tokenRegistry.getTokensAsync();
+        coinbase = userAddresses[0];
+        addressWithoutFunds = userAddresses[1];
     });
     beforeEach(async () => {
         await blockchainLifecycle.startAsync();
@@ -30,85 +34,190 @@ describe('TokenWrapper', () => {
         await blockchainLifecycle.revertAsync();
     });
     describe('#transferAsync', () => {
+        let token: Token;
+        let transferAmount: BigNumber.BigNumber;
+        before(() => {
+            token = tokens[0];
+            transferAmount = new BigNumber(42);
+        });
         it('should successfully transfer tokens', async () => {
-            const token = tokens[0];
-            const fromAddress = userAddresses[0];
-            const toAddress = userAddresses[1];
+            const fromAddress = coinbase;
+            const toAddress = addressWithoutFunds;
             const preBalance = await zeroEx.token.getBalanceAsync(token.address, toAddress);
             expect(preBalance).to.be.bignumber.equal(0);
-            const transferAmount = new BigNumber(42);
             await zeroEx.token.transferAsync(token.address, fromAddress, toAddress, transferAmount);
             const postBalance = await zeroEx.token.getBalanceAsync(token.address, toAddress);
-            expect(postBalance).to.be.bignumber.equal(transferAmount);
+            return expect(postBalance).to.be.bignumber.equal(transferAmount);
+        });
+        it('should fail to transfer tokens if fromAddress has an insufficient balance', async () => {
+            const fromAddress = addressWithoutFunds;
+            const toAddress = coinbase;
+            return expect(zeroEx.token.transferAsync(
+                token.address, fromAddress, toAddress, transferAmount,
+            )).to.be.rejectedWith(ZeroExError.INSUFFICIENT_BALANCE_FOR_TRANSFER);
         });
         it('should throw a CONTRACT_DOES_NOT_EXIST error for a non-existent token contract', async () => {
             const nonExistentTokenAddress = '0x9dd402f14d67e001d8efbe6583e51bf9706aa065';
-            const fromAddress = userAddresses[0];
-            const toAddress = userAddresses[0];
-            expect(zeroEx.token.transferAsync(
-                nonExistentTokenAddress, fromAddress, toAddress, new BigNumber(42),
+            const fromAddress = coinbase;
+            const toAddress = coinbase;
+            return expect(zeroEx.token.transferAsync(
+                nonExistentTokenAddress, fromAddress, toAddress, transferAmount,
+            )).to.be.rejectedWith(ZeroExError.CONTRACT_DOES_NOT_EXIST);
+        });
+    });
+    describe('#transferFromAsync', () => {
+        let token: Token;
+        let toAddress: string;
+        let senderAddress: string;
+        before(async () => {
+            token = tokens[0];
+            toAddress = addressWithoutFunds;
+            senderAddress = userAddresses[2];
+        });
+        it('should fail to transfer tokens if fromAddress has insufficient allowance set', async () => {
+            const fromAddress = coinbase;
+            const transferAmount = new BigNumber(42);
+
+            const fromAddressBalance = await zeroEx.token.getBalanceAsync(token.address, fromAddress);
+            expect(fromAddressBalance).to.be.bignumber.greaterThan(transferAmount);
+
+            const fromAddressAllowance = await zeroEx.token.getAllowanceAsync(token.address, fromAddress,
+                                                                              toAddress);
+            expect(fromAddressAllowance).to.be.bignumber.equal(0);
+
+            return expect(zeroEx.token.transferFromAsync(
+                token.address, fromAddress, toAddress, senderAddress, transferAmount,
+            )).to.be.rejectedWith(ZeroExError.INSUFFICIENT_ALLOWANCE_FOR_TRANSFER);
+        });
+        it('should fail to transfer tokens if fromAddress has insufficient balance', async () => {
+            const fromAddress = addressWithoutFunds;
+            const transferAmount = new BigNumber(42);
+
+            const fromAddressBalance = await zeroEx.token.getBalanceAsync(token.address, fromAddress);
+            expect(fromAddressBalance).to.be.bignumber.equal(0);
+
+            await zeroEx.token.setAllowanceAsync(token.address, fromAddress, senderAddress, transferAmount);
+            const fromAddressAllowance = await zeroEx.token.getAllowanceAsync(token.address, fromAddress,
+                                                                              senderAddress);
+            expect(fromAddressAllowance).to.be.bignumber.equal(transferAmount);
+
+            return expect(zeroEx.token.transferFromAsync(
+                token.address, fromAddress, toAddress, senderAddress, transferAmount,
+            )).to.be.rejectedWith(ZeroExError.INSUFFICIENT_BALANCE_FOR_TRANSFER);
+        });
+        it('should successfully transfer tokens', async () => {
+            const fromAddress = coinbase;
+
+            const preBalance = await zeroEx.token.getBalanceAsync(token.address, toAddress);
+            expect(preBalance).to.be.bignumber.equal(0);
+
+            const transferAmount = new BigNumber(42);
+            await zeroEx.token.setAllowanceAsync(token.address, fromAddress, senderAddress, transferAmount);
+
+            await zeroEx.token.transferFromAsync(token.address, fromAddress, toAddress, senderAddress,
+                                                 transferAmount);
+            const postBalance = await zeroEx.token.getBalanceAsync(token.address, toAddress);
+            return expect(postBalance).to.be.bignumber.equal(transferAmount);
+        });
+        it('should throw a CONTRACT_DOES_NOT_EXIST error for a non-existent token contract', async () => {
+            const fromAddress = coinbase;
+            const nonExistentTokenAddress = '0x9dd402f14d67e001d8efbe6583e51bf9706aa065';
+            return expect(zeroEx.token.transferFromAsync(
+                nonExistentTokenAddress, fromAddress, toAddress, senderAddress, new BigNumber(42),
             )).to.be.rejectedWith(ZeroExError.CONTRACT_DOES_NOT_EXIST);
         });
     });
     describe('#getBalanceAsync', () => {
         it('should return the balance for an existing ERC20 token', async () => {
             const token = tokens[0];
-            const ownerAddress = userAddresses[0];
+            const ownerAddress = coinbase;
             const balance = await zeroEx.token.getBalanceAsync(token.address, ownerAddress);
             const expectedBalance = new BigNumber('100000000000000000000000000');
-            expect(balance).to.be.bignumber.equal(expectedBalance);
+            return expect(balance).to.be.bignumber.equal(expectedBalance);
         });
         it('should throw a CONTRACT_DOES_NOT_EXIST error for a non-existent token contract', async () => {
             const nonExistentTokenAddress = '0x9dd402f14d67e001d8efbe6583e51bf9706aa065';
-            const ownerAddress = userAddresses[0];
-            expect(zeroEx.token.getBalanceAsync(nonExistentTokenAddress, ownerAddress))
+            const ownerAddress = coinbase;
+            return expect(zeroEx.token.getBalanceAsync(nonExistentTokenAddress, ownerAddress))
                 .to.be.rejectedWith(ZeroExError.CONTRACT_DOES_NOT_EXIST);
         });
         it('should return a balance of 0 for a non-existent owner address', async () => {
             const token = tokens[0];
             const nonExistentOwner = '0x198C6Ad858F213Fb31b6FE809E25040E6B964593';
             const balance = await zeroEx.token.getBalanceAsync(token.address, nonExistentOwner);
-            const expectedBalance = new BigNumber('0');
-            expect(balance).to.be.bignumber.equal(expectedBalance);
+            const expectedBalance = new BigNumber(0);
+            return expect(balance).to.be.bignumber.equal(expectedBalance);
         });
     });
-    describe('#getProxyAllowanceAsync', () => {
+    describe('#setAllowanceAsync', () => {
+        it('should set the spender\'s allowance', async () => {
+            const token = tokens[0];
+            const ownerAddress = coinbase;
+            const spenderAddress = addressWithoutFunds;
+
+            const allowanceBeforeSet = await zeroEx.token.getAllowanceAsync(token.address, ownerAddress,
+                                                                            spenderAddress);
+            const expectedAllowanceBeforeAllowanceSet = new BigNumber(0);
+            expect(allowanceBeforeSet).to.be.bignumber.equal(expectedAllowanceBeforeAllowanceSet);
+
+            const amountInBaseUnits = new BigNumber(50);
+            await zeroEx.token.setAllowanceAsync(token.address, ownerAddress, spenderAddress, amountInBaseUnits);
+
+            const allowanceAfterSet = await zeroEx.token.getAllowanceAsync(token.address, ownerAddress, spenderAddress);
+            const expectedAllowanceAfterAllowanceSet = amountInBaseUnits;
+            return expect(allowanceAfterSet).to.be.bignumber.equal(expectedAllowanceAfterAllowanceSet);
+        });
+    });
+    describe('#getAllowanceAsync', () => {
         it('should get the proxy allowance', async () => {
             const token = tokens[0];
-            const ownerAddress = userAddresses[0];
+            const ownerAddress = coinbase;
+            const spenderAddress = addressWithoutFunds;
 
-            const amountInUnits = new BigNumber('50');
-            const amountInBaseUnits = ZeroEx.toBaseUnitAmount(amountInUnits, token.decimals);
-            await zeroEx.token.setProxyAllowanceAsync(token.address, ownerAddress, amountInBaseUnits);
+            const amountInBaseUnits = new BigNumber(50);
+            await zeroEx.token.setAllowanceAsync(token.address, ownerAddress, spenderAddress, amountInBaseUnits);
 
-            const allowance = await zeroEx.token.getProxyAllowanceAsync(token.address, ownerAddress);
+            const allowance = await zeroEx.token.getAllowanceAsync(token.address, ownerAddress, spenderAddress);
             const expectedAllowance = amountInBaseUnits;
-            expect(allowance).to.be.bignumber.equal(expectedAllowance);
+            return expect(allowance).to.be.bignumber.equal(expectedAllowance);
         });
         it('should return 0 if no allowance set yet', async () => {
             const token = tokens[0];
-            const ownerAddress = userAddresses[0];
+            const ownerAddress = coinbase;
+            const spenderAddress = addressWithoutFunds;
+            const allowance = await zeroEx.token.getAllowanceAsync(token.address, ownerAddress, spenderAddress);
+            const expectedAllowance = new BigNumber(0);
+            return expect(allowance).to.be.bignumber.equal(expectedAllowance);
+        });
+    });
+    describe('#getProxyAllowanceAsync', () => {
+        it('should get the proxy allowance', async () => {
+            const token = tokens[0];
+            const ownerAddress = coinbase;
+
+            const amountInBaseUnits = new BigNumber(50);
+            await zeroEx.token.setProxyAllowanceAsync(token.address, ownerAddress, amountInBaseUnits);
+
             const allowance = await zeroEx.token.getProxyAllowanceAsync(token.address, ownerAddress);
-            const expectedAllowance = new BigNumber('0');
-            expect(allowance).to.be.bignumber.equal(expectedAllowance);
+            const expectedAllowance = amountInBaseUnits;
+            return expect(allowance).to.be.bignumber.equal(expectedAllowance);
         });
     });
     describe('#setProxyAllowanceAsync', () => {
         it('should set the proxy allowance', async () => {
             const token = tokens[0];
-            const ownerAddress = userAddresses[0];
+            const ownerAddress = coinbase;
 
             const allowanceBeforeSet = await zeroEx.token.getProxyAllowanceAsync(token.address, ownerAddress);
-            const expectedAllowanceBeforeAllowanceSet = new BigNumber('0');
+            const expectedAllowanceBeforeAllowanceSet = new BigNumber(0);
             expect(allowanceBeforeSet).to.be.bignumber.equal(expectedAllowanceBeforeAllowanceSet);
 
-            const amountInUnits = new BigNumber('50');
-            const amountInBaseUnits = ZeroEx.toBaseUnitAmount(amountInUnits, token.decimals);
+            const amountInBaseUnits = new BigNumber(50);
             await zeroEx.token.setProxyAllowanceAsync(token.address, ownerAddress, amountInBaseUnits);
 
             const allowanceAfterSet = await zeroEx.token.getProxyAllowanceAsync(token.address, ownerAddress);
             const expectedAllowanceAfterAllowanceSet = amountInBaseUnits;
-            expect(allowanceAfterSet).to.be.bignumber.equal(expectedAllowanceAfterAllowanceSet);
+            return expect(allowanceAfterSet).to.be.bignumber.equal(expectedAllowanceAfterAllowanceSet);
         });
     });
 });