Merge branch 'development' into refactor/order-utils/market-utils-api

* development:
  feat: Upgrade TypeScript to 3.0.1
  Add defaults for networkId and pagination
  Update sortingUtils to support Order and SignedOrder
  Change rateUtils to use Order
  Updated CHANGELOG
  Fix lint errors
  Update tests for optional feeRate
  Make feeRate optional with a default of 0
  Add tests for sortingUtils
  Implement sorting utils
  Add tests for rateUtils
  Implement rate utils

7 files changed, 241 insertions, 6 deletions

diff --git a/packages/order-utils/CHANGELOG.json b/packages/order-utils/CHANGELOG.json
index 7cefc1670..6b49d2ee6 100644
--- a/packages/order-utils/CHANGELOG.json
+++ b/packages/order-utils/CHANGELOG.json
@@ -1,5 +1,19 @@
 [
     {
+        "version": "1.0.1-rc.4",
+        "changes": [
+            {
+                "note": "Added rateUtils and sortingUtils",
+                "pr": 953
+            },
+            {
+                "note":
+                    "Update marketUtils api such that all optional parameters are bundled into one optional param and more defaults are provided",
+                "pr": 954
+            }
+        ]
+    },
+    {
         "version": "1.0.1-rc.3",
         "changes": [
             {
@@ -18,11 +32,6 @@
             },
             {
                 "note": "Dependencies updated"
-            },
-            {
-                "note":
-                    "Update marketUtils api such that all optional parameters are bundled into one optional param and more defaults are provided",
-                "pr": 954
             }
         ],
         "timestamp": 1534210131
diff --git a/packages/order-utils/package.json b/packages/order-utils/package.json
index fa8f3563e..bedbdc6d2 100644
--- a/packages/order-utils/package.json
+++ b/packages/order-utils/package.json
@@ -70,7 +70,7 @@
         "sinon": "^4.0.0",
         "tslint": "5.11.0",
         "typedoc": "0xProject/typedoc",
-        "typescript": "2.9.2"
+        "typescript": "3.0.1"
     },
     "dependencies": {
         "@0xproject/assert": "^1.0.5",
diff --git a/packages/order-utils/src/index.ts b/packages/order-utils/src/index.ts
index 681fbc904..2b1c92973 100644
--- a/packages/order-utils/src/index.ts
+++ b/packages/order-utils/src/index.ts
@@ -25,3 +25,5 @@ export { EIP712Utils } from './eip712_utils';
 export { OrderValidationUtils } from './order_validation_utils';
 export { ExchangeTransferSimulator } from './exchange_transfer_simulator';
 export { marketUtils } from './market_utils';
+export { rateUtils } from './rate_utils';
+export { sortingUtils } from './sorting_utils';
diff --git a/packages/order-utils/src/rate_utils.ts b/packages/order-utils/src/rate_utils.ts
new file mode 100644
index 000000000..c9ca72c59
--- /dev/null
+++ b/packages/order-utils/src/rate_utils.ts
@@ -0,0 +1,48 @@
+import { schemas } from '@0xproject/json-schemas';
+import { Order } from '@0xproject/types';
+import { BigNumber } from '@0xproject/utils';
+
+import { assert } from './assert';
+import { constants } from './constants';
+
+export const rateUtils = {
+    /**
+     * Takes an order and calculates the fee adjusted rate (takerAsset/makerAsset) by calculating how much takerAsset
+     * is required to cover the fees (feeRate * takerFee), adding the takerAssetAmount and dividing by makerAssetAmount
+     * @param   order       An object that conforms to the order interface
+     * @param   feeRate     The market rate of ZRX denominated in takerAssetAmount
+     *                      (ex. feeRate is 0.1 takerAsset/ZRX if it takes 1 unit of takerAsset to buy 10 ZRX)
+     *                      Defaults to 0
+     * @return  The rate (takerAsset/makerAsset) of the order adjusted for fees
+     */
+    getFeeAdjustedRateOfOrder(order: Order, feeRate: BigNumber = constants.ZERO_AMOUNT): BigNumber {
+        assert.doesConformToSchema('order', order, schemas.orderSchema);
+        assert.isBigNumber('feeRate', feeRate);
+        assert.assert(
+            feeRate.gte(constants.ZERO_AMOUNT),
+            `Expected feeRate: ${feeRate} to be greater than or equal to 0`,
+        );
+        const takerAssetAmountNeededToPayForFees = order.takerFee.mul(feeRate);
+        const totalTakerAssetAmount = takerAssetAmountNeededToPayForFees.plus(order.takerAssetAmount);
+        const rate = totalTakerAssetAmount.div(order.makerAssetAmount);
+        return rate;
+    },
+    /**
+     * Takes a fee order (makerAssetData corresponds to ZRX and takerAssetData corresponds to WETH) and calculates
+     * the fee adjusted rate (WETH/ZRX) by dividing the takerAssetAmount by the makerAmount minus the takerFee
+     * @param   feeOrder    An object that conforms to the order interface
+     * @return  The rate (WETH/ZRX) of the fee order adjusted for fees
+     */
+    getFeeAdjustedRateOfFeeOrder(feeOrder: Order): BigNumber {
+        assert.doesConformToSchema('feeOrder', feeOrder, schemas.orderSchema);
+        const zrxAmountAfterFees = feeOrder.makerAssetAmount.sub(feeOrder.takerFee);
+        assert.assert(
+            zrxAmountAfterFees.greaterThan(constants.ZERO_AMOUNT),
+            `Expected takerFee: ${JSON.stringify(feeOrder.takerFee)} to be less than makerAssetAmount: ${JSON.stringify(
+                feeOrder.makerAssetAmount,
+            )}`,
+        );
+        const rate = feeOrder.takerAssetAmount.div(zrxAmountAfterFees);
+        return rate;
+    },
+};
diff --git a/packages/order-utils/src/sorting_utils.ts b/packages/order-utils/src/sorting_utils.ts
new file mode 100644
index 000000000..8811bcaf8
--- /dev/null
+++ b/packages/order-utils/src/sorting_utils.ts
@@ -0,0 +1,54 @@
+import { schemas } from '@0xproject/json-schemas';
+import { Order } from '@0xproject/types';
+import { BigNumber } from '@0xproject/utils';
+import * as _ from 'lodash';
+
+import { assert } from './assert';
+import { constants } from './constants';
+import { rateUtils } from './rate_utils';
+
+export const sortingUtils = {
+    /**
+     * Takes an array of orders and sorts them by takerAsset/makerAsset rate in ascending order (best rate first).
+     * Adjusts the rate of each order according to the feeRate and takerFee for that order.
+     * @param   orders      An array of objects that extend the Order interface. All orders should specify ZRX as
+     *                      the makerAsset and WETH as the takerAsset.
+     * @param   feeRate     The market rate of ZRX denominated in takerAssetAmount
+     *                      (ex. feeRate is 0.1 takerAsset/ZRX if it takes 1 unit of takerAsset to buy 10 ZRX)
+     *                      Defaults to 0
+     * @return  The input orders sorted by rate in ascending order
+     */
+    sortOrdersByFeeAdjustedRate<T extends Order>(orders: T[], feeRate: BigNumber = constants.ZERO_AMOUNT): T[] {
+        assert.doesConformToSchema('orders', orders, schemas.ordersSchema);
+        assert.isBigNumber('feeRate', feeRate);
+        const rateCalculator = (order: Order) => rateUtils.getFeeAdjustedRateOfOrder(order, feeRate);
+        const sortedOrders = sortOrders(orders, rateCalculator);
+        return sortedOrders;
+    },
+    /**
+     * Takes an array of fee orders (makerAssetData corresponds to ZRX and takerAssetData corresponds to WETH)
+     * and sorts them by rate in ascending order (best rate first). Adjusts the rate according to the takerFee.
+     * @param   feeOrders       An array of objects that extend the Order interface. All orders should specify ZRX as
+     *                          the makerAsset and WETH as the takerAsset.
+     * @return  The input orders sorted by rate in ascending order
+     */
+    sortFeeOrdersByFeeAdjustedRate(feeOrders: Order[]): Order[] {
+        assert.doesConformToSchema('feeOrders', feeOrders, schemas.ordersSchema);
+        const rateCalculator = rateUtils.getFeeAdjustedRateOfFeeOrder.bind(rateUtils);
+        const sortedOrders = sortOrders(feeOrders, rateCalculator);
+        return sortedOrders;
+    },
+};
+
+type RateCalculator = (order: Order) => BigNumber;
+
+// takes an array of orders, copies them, and sorts the copy based on the rate definition provided by rateCalculator
+function sortOrders<T extends Order>(orders: T[], rateCalculator: RateCalculator): T[] {
+    const copiedOrders = _.cloneDeep(orders);
+    copiedOrders.sort((firstOrder, secondOrder) => {
+        const firstOrderRate = rateCalculator(firstOrder);
+        const secondOrderRate = rateCalculator(secondOrder);
+        return firstOrderRate.comparedTo(secondOrderRate);
+    });
+    return copiedOrders;
+}
diff --git a/packages/order-utils/test/rate_utils_test.ts b/packages/order-utils/test/rate_utils_test.ts
new file mode 100644
index 000000000..2e299c209
--- /dev/null
+++ b/packages/order-utils/test/rate_utils_test.ts
@@ -0,0 +1,55 @@
+import { BigNumber } from '@0xproject/utils';
+import * as chai from 'chai';
+import 'mocha';
+
+import { rateUtils } from '../src';
+
+import { chaiSetup } from './utils/chai_setup';
+import { testOrderFactory } from './utils/test_order_factory';
+
+chaiSetup.configure();
+const expect = chai.expect;
+
+describe('rateUtils', () => {
+    const testOrder = testOrderFactory.generateTestSignedOrder({
+        makerAssetAmount: new BigNumber(100),
+        takerAssetAmount: new BigNumber(100),
+        takerFee: new BigNumber(20),
+    });
+    describe('#getFeeAdjustedRateOfOrder', () => {
+        it('throws when feeRate is less than zero', async () => {
+            const feeRate = new BigNumber(-1);
+            expect(() => rateUtils.getFeeAdjustedRateOfOrder(testOrder, feeRate)).to.throw(
+                'Expected feeRate: -1 to be greater than or equal to 0',
+            );
+        });
+        it('correctly calculates fee adjusted rate when feeRate is provided', async () => {
+            const feeRate = new BigNumber(2); // ZRX costs 2 units of takerAsset per 1 unit of ZRX
+            const feeAdjustedRate = rateUtils.getFeeAdjustedRateOfOrder(testOrder, feeRate);
+            // the order actually takes 100 + (2 * 20) takerAsset units to fill 100 units of makerAsset
+            expect(feeAdjustedRate).to.bignumber.equal(new BigNumber(1.4));
+        });
+        it('correctly calculates fee adjusted rate when no feeRate is provided', async () => {
+            const feeAdjustedRate = rateUtils.getFeeAdjustedRateOfOrder(testOrder);
+            // because no feeRate was provided we just assume 0 fees
+            // the order actually takes 100 takerAsset units to fill 100 units of makerAsset
+            expect(feeAdjustedRate).to.bignumber.equal(new BigNumber(1));
+        });
+    });
+    describe('#getFeeAdjustedRateOfFeeOrder', () => {
+        it('throws when takerFee exceeds makerAssetAmount', async () => {
+            const badOrder = testOrderFactory.generateTestSignedOrder({
+                makerAssetAmount: new BigNumber(100),
+                takerFee: new BigNumber(101),
+            });
+            expect(() => rateUtils.getFeeAdjustedRateOfFeeOrder(badOrder)).to.throw(
+                'Expected takerFee: "101" to be less than makerAssetAmount: "100"',
+            );
+        });
+        it('correctly calculates fee adjusted rate', async () => {
+            const feeAdjustedRate = rateUtils.getFeeAdjustedRateOfFeeOrder(testOrder);
+            // the order actually takes 100 takerAsset units to fill (100 - 20) units of makerAsset
+            expect(feeAdjustedRate).to.bignumber.equal(new BigNumber(1.25));
+        });
+    });
+});
diff --git a/packages/order-utils/test/sorting_utils_test.ts b/packages/order-utils/test/sorting_utils_test.ts
new file mode 100644
index 000000000..016432505
--- /dev/null
+++ b/packages/order-utils/test/sorting_utils_test.ts
@@ -0,0 +1,67 @@
+import { BigNumber } from '@0xproject/utils';
+import * as chai from 'chai';
+import 'mocha';
+
+import { sortingUtils } from '../src';
+
+import { chaiSetup } from './utils/chai_setup';
+import { testOrderFactory } from './utils/test_order_factory';
+
+chaiSetup.configure();
+const expect = chai.expect;
+
+describe('sortingUtils', () => {
+    describe('#sortOrdersByFeeAdjustedRate', () => {
+        const feeRate = new BigNumber(1); // ZRX costs 1 unit of takerAsset per 1 unit of ZRX
+        // rate: 2 takerAsset / makerAsset
+        const testOrder1 = testOrderFactory.generateTestSignedOrder({
+            makerAssetAmount: new BigNumber(100),
+            takerAssetAmount: new BigNumber(200),
+        });
+        // rate: 1 takerAsset / makerAsset
+        const testOrder2 = testOrderFactory.generateTestSignedOrder({
+            makerAssetAmount: new BigNumber(100),
+            takerAssetAmount: new BigNumber(100),
+        });
+        // rate: 2.5 takerAsset / makerAsset
+        const testOrder3 = testOrderFactory.generateTestSignedOrder({
+            makerAssetAmount: new BigNumber(100),
+            takerAssetAmount: new BigNumber(200),
+            takerFee: new BigNumber(50),
+        });
+        it('correctly sorts by fee adjusted rate when feeRate is Provided', async () => {
+            const orders = [testOrder1, testOrder2, testOrder3];
+            const sortedOrders = sortingUtils.sortOrdersByFeeAdjustedRate(orders, feeRate);
+            expect(sortedOrders).to.deep.equal([testOrder2, testOrder1, testOrder3]);
+        });
+        it('correctly sorts by fee adjusted rate when no feeRate is Provided', async () => {
+            const orders = [testOrder1, testOrder2, testOrder3];
+            const sortedOrders = sortingUtils.sortOrdersByFeeAdjustedRate(orders);
+            expect(sortedOrders).to.deep.equal([testOrder2, testOrder1, testOrder3]);
+        });
+    });
+    describe('#sortFeeOrdersByFeeAdjustedRate', () => {
+        // rate: 200 takerAsset / makerAsset
+        const testOrder1 = testOrderFactory.generateTestSignedOrder({
+            makerAssetAmount: new BigNumber(100),
+            takerAssetAmount: new BigNumber(200),
+            takerFee: new BigNumber(99),
+        });
+        // rate: 1 takerAsset / makerAsset
+        const testOrder2 = testOrderFactory.generateTestSignedOrder({
+            makerAssetAmount: new BigNumber(100),
+            takerAssetAmount: new BigNumber(100),
+        });
+        // rate: 4 takerAsset / makerAsset
+        const testOrder3 = testOrderFactory.generateTestSignedOrder({
+            makerAssetAmount: new BigNumber(100),
+            takerAssetAmount: new BigNumber(200),
+            takerFee: new BigNumber(50),
+        });
+        it('correctly sorts by fee adjusted rate', async () => {
+            const orders = [testOrder1, testOrder2, testOrder3];
+            const sortedOrders = sortingUtils.sortFeeOrdersByFeeAdjustedRate(orders);
+            expect(sortedOrders).to.deep.equal([testOrder2, testOrder3, testOrder1]);
+        });
+    });
+});