Merge pull request #170 from 0xProject/addOrderValidation

Add validateOrderFillableOrThrowAsync Method

6 files changed, 109 insertions, 8 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7c0d0cb88..add5714e6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,7 @@
 # CHANGELOG
 
 v0.17.0 - _September 26, 2017_
+    * Added `zeroEx.exchange.validateOrderFillableOrThrowAsync` to simplify orderbook pruning (#170)
     * Made `zeroEx.exchange.getZRXTokenAddressAsync` public (#171)
 
 v0.16.0 - _September 20, 2017_
diff --git a/src/contract_wrappers/exchange_wrapper.ts b/src/contract_wrappers/exchange_wrapper.ts
index 694f3b71b..6d4d90441 100644
--- a/src/contract_wrappers/exchange_wrapper.ts
+++ b/src/contract_wrappers/exchange_wrapper.ts
@@ -28,6 +28,7 @@ import {
     LogCancelContractEventArgs,
     LogWithDecodedArgs,
     MethodOpts,
+    ValidateOrderFillableOpts,
 } from '../types';
 import {assert} from '../utils/assert';
 import {utils} from '../utils/utils';
@@ -624,6 +625,25 @@ export class ExchangeWrapper extends ContractWrapper {
         return exchangeAddress;
     }
     /**
+     * Checks if order is still fillable and throws an error otherwise. Useful for orderbook
+     * pruning where you want to remove stale orders without knowing who the taker will be.
+     * @param   signedOrder     An object that conforms to the SignedOrder interface. The
+     *                          signedOrder you wish to validate.
+     * @param   opts            An object that conforms to the ValidateOrderFillableOpts
+     *                          interface. Allows specifying a specific fillTakerTokenAmount
+     *                          to validate for.
+     */
+    public async validateOrderFillableOrThrowAsync(
+        signedOrder: SignedOrder, opts?: ValidateOrderFillableOpts,
+    ): Promise<void> {
+        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
+        const zrxTokenAddress = await this.getZRXTokenAddressAsync();
+        const expectedFillTakerTokenAmount = !_.isUndefined(opts) ? opts.expectedFillTakerTokenAmount : undefined;
+        await this._orderValidationUtils.validateOrderFillableOrThrowAsync(
+            signedOrder, zrxTokenAddress, expectedFillTakerTokenAmount,
+        );
+    }
+    /**
      * Checks if order fill will succeed and throws an error otherwise.
      * @param   signedOrder             An object that conforms to the SignedOrder interface. The
      *                                  signedOrder you wish to fill.
diff --git a/src/types.ts b/src/types.ts
index 29fb40e73..2d069f596 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -434,6 +434,16 @@ export interface Artifact {
 }
 
 /*
+ * expectedFillTakerTokenAmount: If specified, the validation method will ensure that the
+ * supplied order maker has a sufficient allowance/balance to fill this amount of the order's
+ * takerTokenAmount. If not specified, the validation method ensures that the maker has a sufficient
+ * allowance/balance to fill the entire remaining order amount.
+ */
+export interface ValidateOrderFillableOpts {
+    expectedFillTakerTokenAmount?: BigNumber.BigNumber;
+}
+
+/*
  * defaultBlock: The block up to which to query the blockchain state. Setting this to a historical block number
  * let's the user query the blockchain's state at an arbitrary point in time. In order for this to work, the
  * backing  Ethereum node must keep the entire historical state of the chain (e.g setting `--pruning=archive`
diff --git a/src/utils/order_validation_utils.ts b/src/utils/order_validation_utils.ts
index 815cd0115..6f7522c41 100644
--- a/src/utils/order_validation_utils.ts
+++ b/src/utils/order_validation_utils.ts
@@ -1,3 +1,4 @@
+import * as _ from 'lodash';
 import {ExchangeContractErrs, SignedOrder, Order, ZeroExError} from '../types';
 import {ZeroEx} from '../0x';
 import {TokenWrapper} from '../contract_wrappers/token_wrapper';
@@ -12,6 +13,23 @@ export class OrderValidationUtils {
         this.tokenWrapper = tokenWrapper;
         this.exchangeWrapper = exchangeWrapper;
     }
+    public async validateOrderFillableOrThrowAsync(
+        signedOrder: SignedOrder, zrxTokenAddress: string, expectedFillTakerTokenAmount?: BigNumber.BigNumber,
+    ): Promise<void> {
+        const orderHash = utils.getOrderHashHex(signedOrder);
+        const unavailableTakerTokenAmount = await this.exchangeWrapper.getUnavailableTakerAmountAsync(orderHash);
+        this.validateRemainingFillAmountNotZeroOrThrow(
+            signedOrder.takerTokenAmount, unavailableTakerTokenAmount,
+        );
+        this.validateOrderNotExpiredOrThrow(signedOrder.expirationUnixTimestampSec);
+        let fillTakerTokenAmount = signedOrder.takerTokenAmount.minus(unavailableTakerTokenAmount);
+        if (!_.isUndefined(expectedFillTakerTokenAmount)) {
+            fillTakerTokenAmount = expectedFillTakerTokenAmount;
+        }
+        await this.validateFillOrderMakerBalancesAllowancesThrowIfInvalidAsync(
+            signedOrder, fillTakerTokenAmount, zrxTokenAddress,
+        );
+    }
     public async validateFillOrderThrowIfInvalidAsync(signedOrder: SignedOrder,
                                                       fillTakerTokenAmount: BigNumber.BigNumber,
                                                       takerAddress: string,
@@ -24,16 +42,13 @@ export class OrderValidationUtils {
             throw new Error(ZeroExError.InvalidSignature);
         }
         const unavailableTakerTokenAmount = await this.exchangeWrapper.getUnavailableTakerAmountAsync(orderHash);
-        if (signedOrder.makerTokenAmount.eq(unavailableTakerTokenAmount)) {
-            throw new Error(ExchangeContractErrs.OrderRemainingFillAmountZero);
-        }
+        this.validateRemainingFillAmountNotZeroOrThrow(
+            signedOrder.takerTokenAmount, unavailableTakerTokenAmount,
+        );
         if (signedOrder.taker !== constants.NULL_ADDRESS && signedOrder.taker !== takerAddress) {
             throw new Error(ExchangeContractErrs.TransactionSenderIsNotFillOrderTaker);
         }
-        const currentUnixTimestampSec = utils.getCurrentUnixTimestamp();
-        if (signedOrder.expirationUnixTimestampSec.lessThan(currentUnixTimestampSec)) {
-            throw new Error(ExchangeContractErrs.OrderFillExpired);
-        }
+        this.validateOrderNotExpiredOrThrow(signedOrder.expirationUnixTimestampSec);
         await this.validateFillOrderBalancesAllowancesThrowIfInvalidAsync(
             signedOrder, fillTakerTokenAmount, takerAddress, zrxTokenAddress,
         );
@@ -147,4 +162,17 @@ export class OrderValidationUtils {
             }
         }
     }
+    private validateRemainingFillAmountNotZeroOrThrow(
+        takerTokenAmount: BigNumber.BigNumber, unavailableTakerTokenAmount: BigNumber.BigNumber,
+    ) {
+        if (takerTokenAmount.eq(unavailableTakerTokenAmount)) {
+            throw new Error(ExchangeContractErrs.OrderRemainingFillAmountZero);
+        }
+    }
+    private validateOrderNotExpiredOrThrow(expirationUnixTimestampSec: BigNumber.BigNumber) {
+        const currentUnixTimestampSec = utils.getCurrentUnixTimestamp();
+        if (expirationUnixTimestampSec.lessThan(currentUnixTimestampSec)) {
+            throw new Error(ExchangeContractErrs.OrderFillExpired);
+        }
+    }
 }
diff --git a/test/order_validation_test.ts b/test/order_validation_test.ts
index 9a621555c..f625433eb 100644
--- a/test/order_validation_test.ts
+++ b/test/order_validation_test.ts
@@ -54,6 +54,46 @@ describe('OrderValidation', () => {
     afterEach(async () => {
         await blockchainLifecycle.revertAsync();
     });
+    describe('validateOrderFillableOrThrowAsync', () => {
+        it('should succeed if the order is fillable', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            await zeroEx.exchange.validateOrderFillableOrThrowAsync(
+                signedOrder,
+            );
+        });
+        it('should succeed if the order is asymmetric and fillable', async () => {
+            const makerFillableAmount = fillableAmount;
+            const takerFillableAmount = fillableAmount.minus(4);
+            const signedOrder = await fillScenarios.createAsymmetricFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress,
+                makerFillableAmount, takerFillableAmount,
+            );
+            await zeroEx.exchange.validateOrderFillableOrThrowAsync(
+                signedOrder,
+            );
+        });
+        it('should throw when the order is fully filled or cancelled', async () => {
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress, fillableAmount,
+            );
+            await zeroEx.exchange.cancelOrderAsync(signedOrder, fillableAmount);
+            return expect(zeroEx.exchange.validateOrderFillableOrThrowAsync(
+                signedOrder,
+            )).to.be.rejectedWith(ExchangeContractErrs.OrderRemainingFillAmountZero);
+        });
+        it('should throw when order is expired', async () => {
+            const expirationInPast = new BigNumber(1496826058); // 7th Jun 2017
+            const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
+                makerTokenAddress, takerTokenAddress, makerAddress, takerAddress,
+                fillableAmount, expirationInPast,
+            );
+            return expect(zeroEx.exchange.validateOrderFillableOrThrowAsync(
+                signedOrder,
+            )).to.be.rejectedWith(ExchangeContractErrs.OrderFillExpired);
+        });
+    });
     describe('validateFillOrderAndThrowIfInvalidAsync', () => {
         it('should throw when the fill amount is zero', async () => {
             const signedOrder = await fillScenarios.createFillableSignedOrderAsync(
diff --git a/test/utils/fill_scenarios.ts b/test/utils/fill_scenarios.ts
index 563415a48..e305759f6 100644
--- a/test/utils/fill_scenarios.ts
+++ b/test/utils/fill_scenarios.ts
@@ -62,7 +62,9 @@ export class FillScenarios {
             fillableAmount, fillableAmount,
         );
         const shouldThrowOnInsufficientBalanceOrAllowance = false;
-        await this.zeroEx.exchange.fillOrderAsync(signedOrder, partialFillAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress);
+        await this.zeroEx.exchange.fillOrderAsync(
+            signedOrder, partialFillAmount, shouldThrowOnInsufficientBalanceOrAllowance, takerAddress,
+        );
         return signedOrder;
     }
     private async createAsymmetricFillableSignedOrderWithFeesAsync(