feat(BytesArrayUtils): Add BytesArrayUtils library (#248)

* Add BytesLibUtils library

* Rename to BytesArrayUtils; Add mock contract

* Add unit tests

* Use BytesArrayUtils in UniswapV3ExchangeAdapterV2

* Add missing import

* Add BytesLib path to javadocs

Author: Sachin

contracts/lib/BytesArrayUtils.sol

@@ -0,0 +1,49 @@
+/*
+    Copyright 2022 Set Labs 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.
+
+    SPDX-License-Identifier: Apache License, Version 2.0
+*/
+
+pragma solidity 0.6.10;
+
+/**
+ * @title BytesArrayUtils
+ * @author Set Protocol
+ *
+ * Utility library to type cast bytes arrays. Extends BytesLib (external/contracts/uniswap/v3/lib/BytesLib.sol)
+ * library functionality.
+ */
+library BytesArrayUtils {
+
+    /**
+     * Type cast byte to boolean.
+     * @param _bytes        Bytes array
+     * @param _start        Starting index
+     * @return bool        Boolean value
+     */
+    function toBool(bytes memory _bytes, uint256 _start) internal pure returns (bool) {
+        require(_start + 1 >= _start, "toBool_overflow");
+        require(_bytes.length >= _start + 1, "toBool_outOfBounds");
+        uint8 tempUint;
+
+        assembly {
+            tempUint := mload(add(add(_bytes, 0x1), _start))
+        }
+
+        require(tempUint <= 1, "Invalid bool data");     // Should be either 0 or 1
+
+        return (tempUint == 0) ? false : true;
+    }
+}

contracts/mocks/BytesArrayUtilsMock.sol

@@ -0,0 +1,31 @@
+/*
+    Copyright 2022 Set Labs 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.
+
+    SPDX-License-Identifier: Apache License, Version 2.0
+*/
+
+pragma solidity 0.6.10;
+pragma experimental "ABIEncoderV2";
+
+import { BytesArrayUtils } from "../lib/BytesArrayUtils.sol";
+
+
+contract BytesArrayUtilsMock {
+    using BytesArrayUtils for bytes;
+
+    function testToBool(bytes memory _bytes, uint256 _start) external pure returns (bool) {
+        return _bytes.toBool(_start);
+    }
+}

contracts/protocol/integration/exchange/UniswapV3ExchangeAdapterV2.sol

@@ -19,6 +19,7 @@
 pragma solidity 0.6.10;
 pragma experimental "ABIEncoderV2";
 
+import { BytesArrayUtils } from "../../../lib/BytesArrayUtils.sol";
 import { BytesLib } from "../../../../external/contracts/uniswap/v3/lib/BytesLib.sol";
 import { ISwapRouter } from "../../../interfaces/external/ISwapRouter.sol";
 
@@ -35,6 +36,7 @@ import { ISwapRouter } from "../../../interfaces/external/ISwapRouter.sol";
 contract UniswapV3ExchangeAdapterV2 {
 
     using BytesLib for bytes;
+    using BytesArrayUtils for bytes;
 
     /* ============ State Variables ============ */
 
@@ -87,7 +89,7 @@ contract UniswapV3ExchangeAdapterV2 {
         // For multi-hop trades, `_data.length` is greater than 44.
         require(_data.length >= 44, "Invalid data");
 
-        bool fixInput = toBool(_data, _data.length - 1);        // `fixInput` bool is stored at last byte
+        bool fixInput = _data.toBool(_data.length - 1);        // `fixInput` bool is stored at last byte
 
         address sourceFromPath;
         address destinationFromPath;
@@ -167,22 +169,4 @@ contract UniswapV3ExchangeAdapterV2 {
         // Encode fixIn
         return abi.encodePacked(data, _fixIn);
     }
-
-    /**
-     * Helper function to decode bytes to boolean. Similar to functions found in BytesLib.
-     * Note: Access modifier is set to public to enable complete testing.
-     */
-    function toBool(bytes memory _bytes, uint256 _start) public pure returns (bool) {
-        require(_start + 1 >= _start, "toBool_overflow");
-        require(_bytes.length >= _start + 1, "toBool_outOfBounds");
-        uint8 tempUint;
-
-        assembly {
-            tempUint := mload(add(add(_bytes, 0x1), _start))
-        }
-
-        require(tempUint <= 1, "Invalid bool data");     // Should be either 0 or 1
-
-        return (tempUint == 0) ? false : true;
-    }
 }

test/lib/bytesArrayUtils.spec.ts

@@ -0,0 +1,106 @@
+import "module-alias/register";
+import { BigNumber } from "ethers";
+import { solidityPack } from "ethers/lib/utils";
+
+import { Address, Bytes } from "@utils/types";
+import { Account } from "@utils/test/types";
+import { MAX_UINT_256 } from "@utils/constants";
+import { BytesArrayUtilsMock } from "@utils/contracts";
+import DeployHelper from "@utils/deploys";
+import {
+  addSnapshotBeforeRestoreAfterEach,
+  getAccounts,
+  getWaffleExpect,
+  getRandomAddress
+} from "@utils/test/index";
+
+const expect = getWaffleExpect();
+
+describe("BytesArrayUtils", () => {
+  let owner: Account;
+  let deployer: DeployHelper;
+
+  let bytesArrayUtils: BytesArrayUtilsMock;
+
+
+  before(async () => {
+    [
+      owner,
+    ] = await getAccounts();
+
+    deployer = new DeployHelper(owner.wallet);
+    bytesArrayUtils = await deployer.mocks.deployBytesArrayUtilsMock();
+  });
+
+  addSnapshotBeforeRestoreAfterEach();
+
+  describe("#toBool", async () => {
+    let bool: boolean;
+    let randomAddress: Address;
+
+    let subjectBytes: Bytes;
+    let subjectStart: BigNumber;
+
+    before(async () => {
+      randomAddress = await getRandomAddress();
+    });
+
+    beforeEach(async() => {
+      bool = true;
+
+      subjectBytes = solidityPack(
+        ["address", "bool"],
+        [randomAddress, bool]
+      );
+      subjectStart = BigNumber.from(20);    // Address is 20 bytes long
+    });
+
+    async function subject(): Promise<boolean> {
+      return await bytesArrayUtils.testToBool(subjectBytes, subjectStart);
+    }
+
+    it("should return correct bool", async () => {
+      const actualBool = await subject();
+
+      expect(actualBool).to.eq(bool);
+    });
+
+    describe("when bool is false", async () => {
+      beforeEach(async() => {
+        bool = false;
+
+        subjectBytes = solidityPack(
+          ["address", "bool"],
+          [randomAddress, bool]
+        );
+      });
+
+      it("should return correct bool", async () => {
+        const actualBool = await subject();
+
+        expect(actualBool).to.eq(bool);
+      });
+    });
+
+    describe("when start is max uint 256", async () => {
+      beforeEach(() => {
+        subjectStart = MAX_UINT_256;
+      });
+
+      it("should revert", async () => {
+        await expect(subject()).to.be.revertedWith("toBool_overflow");
+      });
+    });
+
+
+    describe("when start is out of bounds", async () => {
+      beforeEach(() => {
+        subjectStart = BigNumber.from(subjectBytes.length);
+      });
+
+      it("should revert", async () => {
+        await expect(subject()).to.be.revertedWith("toBool_outOfBounds");
+      });
+    });
+  });
+});

test/protocol/integration/exchange/uniswapV3ExchangeAdapterV2.spec.ts

@@ -4,7 +4,7 @@ import { solidityPack } from "ethers/lib/utils";
 
 import { Address, Bytes } from "@utils/types";
 import { Account } from "@utils/test/types";
-import { MAX_UINT_256, ZERO } from "@utils/constants";
+import { ZERO } from "@utils/constants";
 import { UniswapV3ExchangeAdapterV2 } from "@utils/contracts";
 import DeployHelper from "@utils/deploys";
 import { ether } from "@utils/index";
@@ -271,74 +271,4 @@ describe("UniswapV3ExchangeAdapterV2", () => {
       });
     });
   });
-
-  describe("#toBool", async () => {
-    let bool: boolean;
-    let randomAddress: Address;
-
-    let subjectBytes: Bytes;
-    let subjectStart: BigNumber;
-
-    before(async () => {
-      randomAddress = await getRandomAddress();
-    });
-
-    beforeEach(async() => {
-      bool = true;
-
-      subjectBytes = solidityPack(
-        ["address", "bool"],
-        [randomAddress, bool]
-      );
-      subjectStart = BigNumber.from(20);    // Address is 20 bytes long
-    });
-
-    async function subject(): Promise<boolean> {
-      return await uniswapV3ExchangeAdapter.toBool(subjectBytes, subjectStart);
-    }
-
-    it("should return correct bool", async () => {
-      const actualBool = await subject();
-
-      expect(actualBool).to.eq(bool);
-    });
-
-    describe("when bool is false", async () => {
-      beforeEach(async() => {
-        bool = false;
-
-        subjectBytes = solidityPack(
-          ["address", "bool"],
-          [randomAddress, bool]
-        );
-      });
-
-      it("should return correct bool", async () => {
-        const actualBool = await subject();
-
-        expect(actualBool).to.eq(bool);
-      });
-    });
-
-    describe("when start is max uint 256", async () => {
-      beforeEach(() => {
-        subjectStart = MAX_UINT_256;
-      });
-
-      it("should revert", async () => {
-        await expect(subject()).to.be.revertedWith("toBool_overflow");
-      });
-    });
-
-
-    describe("when start is out of bounds", async () => {
-      beforeEach(() => {
-        subjectStart = BigNumber.from(subjectBytes.length);
-      });
-
-      it("should revert", async () => {
-        await expect(subject()).to.be.revertedWith("toBool_outOfBounds");
-      });
-    });
-  });
 });

utils/contracts/index.ts

@@ -12,6 +12,7 @@ export { AmmModule } from "../../typechain/AmmModule";
 export { AssetLimitHook } from "../../typechain/AssetLimitHook";
 export { BalancerV1IndexExchangeAdapter } from "../../typechain/BalancerV1IndexExchangeAdapter";
 export { BasicIssuanceModule } from "../../typechain/BasicIssuanceModule";
+export { BytesArrayUtilsMock } from "../../typechain/BytesArrayUtilsMock";
 export { ChainlinkAggregatorMock } from "../../typechain/ChainlinkAggregatorMock";
 export { ClaimAdapterMock } from "../../typechain/ClaimAdapterMock";
 export { ClaimModule } from "../../typechain/ClaimModule";

utils/deploys/deployMocks.ts

@@ -6,6 +6,7 @@ import {
   AaveLendingPoolMock,
   AddressArrayUtilsMock,
   AmmAdapterMock,
+  BytesArrayUtilsMock,
   ChainlinkAggregatorMock,
   ClaimAdapterMock,
   ContractCallerMock,
@@ -66,6 +67,7 @@ import { AaveLendingPoolCoreMock__factory } from "../../typechain/factories/Aave
 import { AaveLendingPoolMock__factory } from "../../typechain/factories/AaveLendingPoolMock__factory";
 import { AddressArrayUtilsMock__factory } from "../../typechain/factories/AddressArrayUtilsMock__factory";
 import { AmmAdapterMock__factory } from "../../typechain/factories/AmmAdapterMock__factory";
+import { BytesArrayUtilsMock__factory } from "../../typechain/factories/BytesArrayUtilsMock__factory";
 import { ChainlinkAggregatorMock__factory } from "../../typechain/factories/ChainlinkAggregatorMock__factory";
 import { ClaimAdapterMock__factory } from "../../typechain/factories/ClaimAdapterMock__factory";
 import { CompoundMock__factory } from "../../typechain/factories/CompoundMock__factory";
@@ -463,6 +465,10 @@ export default class DeployMocks {
     return await new StringArrayUtilsMock__factory(this._deployerSigner).deploy();
   }
 
+  public async deployBytesArrayUtilsMock(): Promise<BytesArrayUtilsMock> {
+    return await new BytesArrayUtilsMock__factory(this._deployerSigner).deploy();
+  }
+
   /** ***********************************
    * Instance getters
    ************************************/