Merge branch 'feature/exchange-rate-getters' into feature/aave-v2

contracts/callManagers/LendingManager/LendingLogicAave.sol

@@ -85,4 +85,12 @@ contract LendingLogicAave is ILendingLogic {
         return(targets, data);
     }
 
+    function exchangeRate(address) external pure override returns(uint256) {
+        return 10**18;
+    }
+
+    function exchangeRateView(address) external pure override returns(uint256) {
+        return 10**18;
+    }
+
 }

contracts/callManagers/LendingManager/LendingLogicCompound.sol

@@ -62,6 +62,7 @@ contract LendingLogicCompound is Ownable, ILendingLogic {
 
         return(targets, data);
     }
+
     function unlend(address _wrapped, uint256 _amount) external view override returns(address[] memory targets, bytes[] memory data) {
         targets = new address[](1);
         data = new bytes[](1);
@@ -72,4 +73,12 @@ contract LendingLogicCompound is Ownable, ILendingLogic {
         return(targets, data);
     }
 
+    function exchangeRate(address _wrapped) external override returns(uint256) {
+        return ICToken(_wrapped).exchangeRateCurrent();
+    }
+
+    function exchangeRateView(address _wrapped) external view override returns(uint256) {
+        return ICToken(_wrapped).exchangeRateStored();
+    }
+
 }

contracts/callManagers/LendingManager/StakeSushi.sol

@@ -60,4 +60,18 @@ contract StakingLogicSushi is ILendingLogic {
         return(targets, data);
     }
 
+    function exchangeRate(address _wrapped) external view override returns(uint256) {
+        return _exchangeRate(_wrapped);
+    }
+
+    function exchangeRateView(address _wrapped) external view override returns(uint256) {
+        return _exchangeRate(_wrapped);
+    }
+
+    function _exchangeRate(address _wrapped) internal view returns(uint256) {
+        IERC20 xToken = IERC20(_wrapped);
+        IERC20 token = IERC20(lendingRegistry.wrappedToUnderlying(_wrapped));
+        return token.balanceOf(_wrapped) * 10**18 / xToken.totalSupply();
+    }
+
 }

contracts/callManagers/LendingManager/StakingLogicYGov.sol

@@ -59,5 +59,13 @@ contract StakingLogicYGov is ILendingLogic {
     function getAPRFromWrapped(address _token) external view override returns(uint256) {
         return uint256(-1);
     }
+
+    function exchangeRate(address _wrapped) external view override returns(uint256) {
+        return IYVault(_wrapped).getPricePerFullShare();
+    }
+
+    function exchangeRateView(address _wrapped) external view override returns(uint256) {
+        return IYVault(_wrapped).getPricePerFullShare();
+    }
 
 }

contracts/interfaces/ICToken.sol

@@ -6,4 +6,6 @@ interface ICToken {
     function mint(uint _mintAmount) external returns (uint256);
     function redeem(uint _redeemTokens) external returns (uint256);
     function supplyRatePerBlock() external view returns (uint256);
+    function exchangeRateCurrent() external returns (uint256);
+    function exchangeRateStored() external view returns(uint256);
 }

contracts/interfaces/ILendingLogic.sol

@@ -34,4 +34,18 @@ interface ILendingLogic {
         @return data Calldata of the calls
     */
     function unlend(address _wrapped, uint256 _amount) external view returns(address[] memory targets, bytes[] memory data);
+
+    /**
+        @notice Get the underlying wrapped exchange rate
+        @param _wrapped Address of the wrapped token
+        @return The exchange rate
+    */
+    function exchangeRate(address _wrapped) external returns(uint256);
+
+    /**
+        @notice Get the underlying wrapped exchange rate in a view (non state changing) way
+        @param _wrapped Address of the wrapped token
+        @return The exchange rate
+    */
+    function exchangeRateView(address _wrapped) external view returns(uint256);
 }

contracts/test/MockCToken.sol

@@ -3,20 +3,23 @@ pragma experimental ABIEncoderV2;
 pragma solidity ^0.7.1;
 
 import "./MockToken.sol";
+import "../interfaces/ICToken.sol";
 import "@openzeppelin/contracts/math/SafeMath.sol";
 
 
-contract MockCToken is MockToken {
+contract MockCToken is MockToken, ICToken {
     using SafeMath for uint256;
+    // representable value taken from cEth
     uint256 public exchangeRate = 1 ether / 5;
     MockToken public underlying;
+    uint256 someValue;
 
     uint256 public errorCode;
     constructor(address _underlying) MockToken("cTOKEN", "cToken") public {
         underlying = MockToken(_underlying);
     }
 
-    function mint(uint256 _amount) external returns(uint256) {
+    function mint(uint256 _amount) external override returns(uint256) {
         require(underlying.transferFrom(msg.sender, address(this), _amount), "MockCToken.mint: transferFrom failed");
 
         uint256 mintAmount = _amount.mul(10**18).div(exchangeRate);
@@ -25,11 +28,7 @@ contract MockCToken is MockToken {
         return errorCode;
     }
 
-    function exchangeRateStored() external view returns(uint256) {
-        return exchangeRate;
-    }
-
-    function redeem(uint256 _amount) external returns(uint256) {
+    function redeem(uint256 _amount) external override returns(uint256) {
         _burn(msg.sender, _amount);
 
         uint256 underlyingAmount = _amount.mul(exchangeRate).div(10**18);
@@ -55,7 +54,19 @@ contract MockCToken is MockToken {
         errorCode = _value;
     }
 
-    function supplyRatePerBlock() external view returns (uint256) {
+    function supplyRatePerBlock() external override view returns (uint256) {
         return 20000000000;
     }
+
+    function exchangeRateCurrent() external override returns(uint256) {
+        // To make function state changing
+        someValue ++;
+        return exchangeRate;
+    }
+
+    function exchangeRateStored() external override view returns(uint256) {
+        // To make function non pure;
+        someValue;
+        return exchangeRate;
+    }
 }

contracts/test/MockLendingLogic.sol

@@ -27,4 +27,12 @@ contract MockLendingLogic is ILendingLogic {
         targets[0] = _wrapped;
         data[0] = bytes(abi.encode(_amount));
     }
+
+    function exchangeRate(address) external pure override returns(uint256) {
+        return 10**18;
+    }
+
+    function exchangeRateView(address) external pure override returns(uint256) {
+        return 10**18;
+    }
 }

contracts/test/MockToken.sol

@@ -5,6 +5,7 @@ pragma solidity ^0.7.1;
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 
 contract MockToken is ERC20 {
+
     constructor(string memory _name, string memory _symbol)
         ERC20(_name, _symbol)
     {}

contracts/test/MockXSushi.sol

@@ -5,7 +5,6 @@ pragma solidity ^0.7.1;
 import "./MockToken.sol";
 import "@openzeppelin/contracts/math/SafeMath.sol";
 
-
 contract MockXSushi is MockToken {
     using SafeMath for uint256;
     uint256 public exchangeRate = 1 ether / 5;

test/lendingLogicAave.ts

@@ -121,5 +121,17 @@ describe("LendingLogicAave", function() {
         const apr = await lendingLogic.getAPRFromWrapped(aToken.address);
         expect(apr).to.eq(ethers.BigNumber.from("10").pow(16)) // one percent
     })
+
+    it("exchangeRate()", async() => {
+        const exchangeRate = await lendingLogic.exchangeRate(aToken.address);
+        // 1 wrapped = 1
+        expect(exchangeRate).to.eq( ethers.BigNumber.from("10").pow(18))
+    })
+
+    it("exchangeRateView()", async() => {
+        const exchangeRate = await lendingLogic.exchangeRateView(aToken.address);
+        // 1 wrapped == 1
+        expect(exchangeRate).to.eq( ethers.BigNumber.from("10").pow(18))
+    })
 
 });

test/lendingLogicCompound.ts

@@ -142,4 +142,17 @@ describe("LendingLogicCompound", function() {
         expect(apr).to.eq(ethers.BigNumber.from("10").pow(16).mul(4)) // 4 percent
     })
 
+    it("exchangeRate()", async() => {
+        await cToken.exchangeRateCurrent()
+        await lendingLogic.exchangeRate(cToken.address);
+    })
+
+    it("exchangeRateView()", async() => {
+        const exchangeRate = await cToken.exchangeRateStored()
+        // 1 wrapped (8 decimals) = 0.2 (8 decimals)
+        expect(exchangeRate).to.eq(ethers.BigNumber.from("10").pow(17).mul(2))
+        const exchangeRateLending = await lendingLogic.exchangeRateView(cToken.address);
+        expect(exchangeRate).to.eq(exchangeRateLending)
+    })
+
 });

test/stakingLogicSushi.ts

@@ -53,6 +53,7 @@ describe("StakingLogicSushi", function() {
 
         await lendingRegistry.setProtocolToLogic(PLACEHOLDER_PROTOCOL, lendingLogic.address);
         await lendingRegistry.setWrappedToProtocol(xSUSHI.address, PLACEHOLDER_PROTOCOL);
+        await lendingRegistry.setWrappedToUnderlying(xSUSHI.address, token.address);
         await lendingRegistry.setUnderlyingToProtocolWrapped(token.address, PLACEHOLDER_PROTOCOL, xSUSHI.address);
 
         await timeTraveler.snapshot();
@@ -127,5 +128,21 @@ describe("StakingLogicSushi", function() {
         const apr = await lendingLogic.getAPRFromWrapped(xSUSHI.address);
         expect(apr).to.eq(ethers.BigNumber.from("2").pow(256).sub(1))
     })
+
+    it("exchangeRate()", async() => {
+        await token.approve(xSUSHI.address, constants.MaxUint256);
+        await xSUSHI["mint(uint256)"](mintAmount);
+
+        await lendingLogic.exchangeRate(xSUSHI.address)
+    })
+
+    it("exchangeRateView()", async() => {
+        await token.approve(xSUSHI.address, constants.MaxUint256);
+        await xSUSHI["mint(uint256)"](mintAmount);
+
+        const exchangeRate = await lendingLogic.exchangeRateView(xSUSHI.address);
+        // 1 xToken = 0.2
+        expect(exchangeRate).to.eq(ethers.BigNumber.from("10").pow(16).mul(20))
+    })
 
 });

test/stakingLogicYVault.ts

@@ -39,7 +39,7 @@ describe("StakingLogicYGov", function() {
         signers = await ethers.getSigners();
         account = await signers[0].getAddress();
         timeTraveler = new TimeTraveler(ethereum);
-        
+
         const tokenFactory = new MockTokenFactory(signers[0]);
         const yGOVFactory = new MockYVaultFactory(signers[0]);
 
@@ -50,11 +50,11 @@ describe("StakingLogicYGov", function() {
 
         lendingRegistry = await (new LendingRegistryFactory(signers[0])).deploy();
         lendingLogic = await deployContract(signers[0], StakingLogicYGovArtifact, [lendingRegistry.address, PLACEHOLDER_PROTOCOL]) as StakingLogicYGov;
-        
+
         await lendingRegistry.setProtocolToLogic(PLACEHOLDER_PROTOCOL, lendingLogic.address);
         await lendingRegistry.setWrappedToProtocol(yGov.address, PLACEHOLDER_PROTOCOL);
         await lendingRegistry.setUnderlyingToProtocolWrapped(token.address, PLACEHOLDER_PROTOCOL, yGov.address);
-        
+
         await timeTraveler.snapshot();
     });
 
@@ -105,7 +105,7 @@ describe("StakingLogicYGov", function() {
 
         expect(calls.targets.length).to.eq(1);
         expect(calls.data.length).to.eq(1);
-        
+
         await signers[0].sendTransaction({
             to: calls.targets[0],
             data: calls.data[0]
@@ -118,4 +118,16 @@ describe("StakingLogicYGov", function() {
         expect(yGovBalance).to.eq(0);
     });
 
+    it("exchangeRate()", async() => {
+        const exchangeRate = await lendingLogic.exchangeRate(yGov.address);
+        // 1 wrapped = 0.2
+        expect(exchangeRate).to.eq(ethers.BigNumber.from("10").pow(16).mul(20))
+    })
+
+    it("exchangeRateView()", async() => {
+        const exchangeRate = await lendingLogic.exchangeRateView(yGov.address);
+        // 1 wrapped == 0.2
+        expect(exchangeRate).to.eq( ethers.BigNumber.from("10").pow(16).mul(20))
+    })
+
 });