[Under Audit] Add Bucket-Lender

contracts/margin/external/BucketLender/BucketLenderFactory.sol

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+/*
+
+    Copyright 2018 dYdX Trading Inc.
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+
+*/
+
+pragma solidity 0.4.24;
+pragma experimental "v0.5.0";
+
+import { Ownable } from "zeppelin-solidity/contracts/ownership/Ownable.sol";
+import { BucketLender } from "./BucketLender.sol";
+
+
+/**
+ * @title BucketLenderFactory
+ * @author dYdX
+ *
+ * Contract that allows anyone to deploy a BucketLender contract by sending a transaction.
+ */
+contract BucketLenderFactory {
+
+    // ============ Events ============
+
+    event BucketLenderCreated(
+        address indexed creator,
+        address at,
+        bytes32 positionId
+    );
+
+    // ============ State Variables ============
+
+    // Address of the Margin contract for the dYdX Margin Trading Protocol
+    address public DYDX_MARGIN;
+
+    // ============ Constructor ============
+
+    constructor(
+        address margin
+    )
+        public
+    {
+        DYDX_MARGIN = margin;
+    }
+
+    // ============ Public Functions ============
+
+    /**
+     * Deploy a new BucketLender contract to the blockchain
+     *
+     * @param  positionId     Unique ID of the position
+     * @param  heldToken      Address of the token held in the position as collateral
+     * @param  owedToken      Address of the token being lent by the BucketLender
+     * @param  parameters     Values corresponding to:
+     *
+     *                        [0] = number of seconds per bucket
+     *                        [1] = interest rate
+     *                        [2] = interest period
+     *                        [3] = maximum loan duration
+     *                        [4] = margin-call timelimit
+     *                        [5] = numerator of minimum heldToken-per-owedToken
+     *                        [6] = denominator of minimum heldToken-per-owedToken
+     *
+     * @param  marginCallers  Accounts that are permitted to margin-call positions (or cancel the margin call)
+     * @return                The address of the new BucketLender contract
+     */
+    function createBucketLender(
+        bytes32 positionId,
+        address heldToken,
+        address owedToken,
+        uint32[7] parameters,
+        address[] marginCallers
+    )
+        external
+        returns (address)
+    {
+        address newBucketLender = new BucketLender(
+            DYDX_MARGIN,
+            positionId,
+            heldToken,
+            owedToken,
+            parameters,
+            marginCallers
+        );
+
+        Ownable(newBucketLender).transferOwnership(msg.sender);
+
+        emit BucketLenderCreated(
+            msg.sender,
+            newBucketLender,
+            positionId
+        );
+
+        return newBucketLender;
+    }
+}

test/margin/external/bucketlender/TestBucketLenderFactory.js

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+const chai = require('chai');
+const expect = chai.expect;
+chai.use(require('chai-bignumber')());
+const BigNumber = require('bignumber.js');
+
+const Margin = artifacts.require("Margin");
+const HeldToken = artifacts.require("TokenA");
+const OwedToken = artifacts.require("TokenB");
+const BucketLender = artifacts.require("BucketLender");
+const BucketLenderFactory = artifacts.require("BucketLenderFactory");
+
+const { transact } = require('../../../helpers/ContractHelper');
+const { ADDRESSES, BYTES32 } = require('../../../helpers/Constants');
+
+contract('BucketLenderFactory', () => {
+
+  // ============ Before/After ============
+
+  beforeEach('set up contracts', async () => {
+  });
+
+  // ============ Constructor ============
+
+  describe('Constructor', () => {
+    it('sets constants correctly', async () => {
+      const marginAddress = ADDRESSES.TEST[0];
+      const factory = await BucketLenderFactory.new(marginAddress);
+      const dydxMargin = await factory.DYDX_MARGIN.call();
+      expect(dydxMargin).to.be.eq(marginAddress);
+    });
+  });
+
+  // ============ Functions ============
+
+  describe('createBucketLender', () => {
+    it('succeeds', async () => {
+      const positionId = BYTES32.TEST[0];
+      const bucketTime = new BigNumber(123);
+      const interestRate = new BigNumber(456);
+      const interestPeriod = new BigNumber(789);
+      const maxDuration = new BigNumber(101112);
+      const callTimelimit = new BigNumber(131415);
+      const numerator = new BigNumber(161718);
+      const denominator = new BigNumber(192021);
+      const marginCaller = ADDRESSES.TEST[0];
+      const notMarginCaller = ADDRESSES.TEST[1];
+
+      const factory = await BucketLenderFactory.new(Margin.address);
+
+      const newBucketLender = await transact(
+        factory.createBucketLender,
+        positionId,
+        HeldToken.address,
+        OwedToken.address,
+        [
+          bucketTime,
+          interestRate,
+          interestPeriod,
+          maxDuration,
+          callTimelimit,
+          numerator,
+          denominator
+        ],
+        [
+          marginCaller
+        ]
+      );
+
+      const bucketLender = await BucketLender.at(newBucketLender.result);
+
+      const [
+        bl_margin,
+        bl_positionId,
+        bl_heldToken,
+        bl_owedToken,
+        bl_bucketTime,
+        bl_interestRate,
+        bl_interestPeriod,
+        bl_maxDuration,
+        bl_callTimelimit,
+        bl_numerator,
+        bl_denominator,
+        bl_marginCallerOkay,
+        bl_notMarginCallerNotOkay,
+      ] = await Promise.all([
+        bucketLender.DYDX_MARGIN.call(),
+        bucketLender.POSITION_ID.call(),
+        bucketLender.HELD_TOKEN.call(),
+        bucketLender.OWED_TOKEN.call(),
+        bucketLender.BUCKET_TIME.call(),
+        bucketLender.INTEREST_RATE.call(),
+        bucketLender.INTEREST_PERIOD.call(),
+        bucketLender.MAX_DURATION.call(),
+        bucketLender.CALL_TIMELIMIT.call(),
+        bucketLender.MIN_HELD_TOKEN_NUMERATOR.call(),
+        bucketLender.MIN_HELD_TOKEN_DENOMINATOR.call(),
+        bucketLender.TRUSTED_MARGIN_CALLERS.call(marginCaller),
+        bucketLender.TRUSTED_MARGIN_CALLERS.call(notMarginCaller),
+      ]);
+
+      expect(bl_margin).to.be.eq(Margin.address);
+      expect(bl_positionId).to.be.eq(positionId);
+      expect(bl_heldToken).to.be.eq(HeldToken.address);
+      expect(bl_owedToken).to.be.eq(OwedToken.address);
+      expect(bl_bucketTime).to.be.bignumber.eq(bucketTime);
+      expect(bl_interestRate).to.be.bignumber.eq(interestRate);
+      expect(bl_interestPeriod).to.be.bignumber.eq(interestPeriod);
+      expect(bl_maxDuration).to.be.bignumber.eq(maxDuration);
+      expect(bl_callTimelimit).to.be.bignumber.eq(callTimelimit);
+      expect(bl_numerator).to.be.bignumber.eq(numerator);
+      expect(bl_denominator).to.be.bignumber.eq(denominator);
+      expect(bl_marginCallerOkay).to.be.eq(true);
+      expect(bl_notMarginCallerNotOkay).to.be.eq(false);
+    });
+  });
+});