Unpriced collateral

contracts/facade/factories/DemurrageCollateralFactory.sol → contracts/facade/factories/CollateralFactory.sol

@@ -2,16 +2,21 @@
 pragma solidity 0.8.19;
 
 import "../../plugins/assets/DemurrageCollateral.sol";
+import "../../plugins/assets/UnpricedCollateral.sol";
 
 /**
- * @title DemurrageCollateralFactory
+ * @title CollateralFactory
  */
-contract DemurrageCollateralFactory {
+contract CollateralFactory {
     event DemurrageCollateralDeployed(address indexed collateral);
+    event UnpricedCollateralDeployed(address indexed collateral);
 
-    // collateral address => fee per second
+    /// @notice collateral address => fee per second
     mapping(address => uint192) public demurrageDeployments;
 
+    /// @notice erc20 address => collateral address
+    mapping(address => address) public unpricedDeployments;
+
     bytes32 public constant USD = bytes32("USD");
 
     function deployNewDemurrageCollateral(
@@ -26,4 +31,13 @@ contract DemurrageCollateralFactory {
         demurrageDeployments[newCollateral] = demurrageConfig.fee;
         emit DemurrageCollateralDeployed(newCollateral);
     }
+
+    function deployNewUnpricedCollateral(IERC20Metadata _erc20)
+        external
+        returns (address newCollateral)
+    {
+        newCollateral = address(new UnpricedCollateral(_erc20));
+        unpricedDeployments[address(_erc20)] = newCollateral;
+        emit UnpricedCollateralDeployed(newCollateral);
+    }
 }

contracts/plugins/assets/UnpricedCollateral.sol

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: BlueOak-1.0.0
+pragma solidity 0.8.19;
+
+import "../../interfaces/IAsset.sol";
+import "./Asset.sol";
+
+/**
+ * @title UnpricedCollateral
+ * @notice Collateral plugin for tokens that are missing a price oracle
+ *
+ * Warning:  This plugin CANNOT be used in an RToken that needs to rebalance
+ *           It should only go into immutable RTokens that cannot have their basket changed
+ *
+ * - tok = X
+ * - ref = X
+ * - target = X
+ * - UoA = USD
+ */
+contract UnpricedCollateral is ICollateral, VersionedAsset {
+    using FixLib for uint192;
+
+    CollateralStatus public constant status = CollateralStatus.SOUND;
+
+    uint192 public constant refPerTok = FIX_ONE;
+
+    uint192 public constant targetPerRef = FIX_ONE;
+
+    uint192 public constant savedPegPrice = 0;
+
+    uint192 public constant maxTradeVolume = 0;
+
+    uint48 public constant lastSave = 0;
+
+    // === Immutables ===
+
+    IERC20Metadata public immutable erc20;
+
+    uint8 public immutable erc20Decimals;
+
+    bytes32 public immutable targetName;
+
+    constructor(IERC20Metadata _erc20) {
+        require(address(_erc20) != address(0), "missing erc20");
+        erc20 = _erc20;
+        erc20Decimals = _erc20.decimals();
+        targetName = bytes32(bytes(_erc20.symbol()));
+    }
+
+    // solhint-disable no-empty-blocks
+
+    /// Should not revert
+    /// Refresh saved prices
+    function refresh() public virtual override {}
+
+    function price() public view virtual override returns (uint192 low, uint192 high) {
+        return (0, FIX_MAX);
+    }
+
+    /// @return {tok} The balance of the ERC20 in whole tokens
+    function bal(address account) external view virtual returns (uint192) {
+        return shiftl_toFix(erc20.balanceOf(account), -int8(erc20Decimals), FLOOR);
+    }
+
+    /// @return If the asset is an instance of ICollateral or not
+    function isCollateral() external pure virtual returns (bool) {
+        return true;
+    }
+
+    /// Claim rewards earned by holding a balance of the ERC20 token
+    /// @custom:delegate-call
+    function claimRewards() external virtual {}
+
+    // solhint-enable no-empty-blocks
+}

test/scenario/UnpricedCollateral.test.ts

@@ -0,0 +1,223 @@
+import { loadFixture, setStorageAt } from '@nomicfoundation/hardhat-network-helpers'
+import { SignerWithAddress } from '@nomiclabs/hardhat-ethers/signers'
+import { expect } from 'chai'
+import { ContractFactory } from 'ethers'
+import { ethers, upgrades } from 'hardhat'
+import { IConfig } from '../../common/configuration'
+import { bn, fp, toBNDecimals } from '../../common/numbers'
+import { MAX_UINT192 } from '../../common/constants'
+import { getTrade } from '../utils/trades'
+import {
+  BasketLibP1,
+  ERC20MockDecimals,
+  IAssetRegistry,
+  TestIBackingManager,
+  TestIBasketHandler,
+  TestIMain,
+  TestIRevenueTrader,
+  TestIRToken,
+  RTokenAsset,
+  UnpricedCollateral,
+} from '../../typechain'
+import { advanceTime } from '../utils/time'
+import { defaultFixtureNoBasket, IMPLEMENTATION, Implementation } from '../fixtures'
+import { CollateralStatus } from '../../common/constants'
+
+const describeP1 = IMPLEMENTATION == Implementation.P1 ? describe : describe.skip
+
+describeP1(`Unpriced Collateral - P${IMPLEMENTATION}`, () => {
+  const amt = fp('1')
+
+  let owner: SignerWithAddress
+  let addr1: SignerWithAddress
+
+  let tokens: ERC20MockDecimals[]
+  let collateral: UnpricedCollateral[]
+  let decimals: number[]
+
+  let config: IConfig
+
+  let main: TestIMain
+  let backingManager: TestIBackingManager
+  let rToken: TestIRToken
+  let assetRegistry: IAssetRegistry
+  let bh: TestIBasketHandler
+  let rTokenAsset: RTokenAsset
+  let rsrTrader: TestIRevenueTrader
+  let rsr: ERC20MockDecimals
+
+  describe('Unpriced Collateral', () => {
+    beforeEach(async () => {
+      ;[owner, addr1] = await ethers.getSigners()
+
+      // Deploy fixture
+      let erc20s: ERC20MockDecimals[]
+      ;({
+        assetRegistry,
+        backingManager,
+        config,
+        main,
+        rToken,
+        erc20s,
+        rTokenAsset,
+        rsrTrader,
+        rsr,
+      } = await loadFixture(defaultFixtureNoBasket))
+
+      // Setup Factories
+      const BasketLibFactory: ContractFactory = await ethers.getContractFactory('BasketLibP1')
+      const basketLib: BasketLibP1 = <BasketLibP1>await BasketLibFactory.deploy()
+      const BasketHandlerFactory: ContractFactory = await ethers.getContractFactory(
+        'BasketHandlerP1',
+        { libraries: { BasketLibP1: basketLib.address } }
+      )
+      const UnpricedCollateralFactory: ContractFactory = await ethers.getContractFactory(
+        'UnpricedCollateral'
+      )
+      const ERC20Factory: ContractFactory = await ethers.getContractFactory('ERC20MockDecimals')
+
+      // Replace with reweightable basket handler
+      bh = await ethers.getContractAt(
+        'TestIBasketHandler',
+        (
+          await upgrades.deployProxy(
+            BasketHandlerFactory,
+            [main.address, config.warmupPeriod, true, true],
+            {
+              initializer: 'init',
+              kind: 'uups',
+            }
+          )
+        ).address
+      )
+      await setStorageAt(main.address, 204, bh.address)
+      await setStorageAt(rToken.address, 355, bh.address)
+      await setStorageAt(backingManager.address, 302, bh.address)
+      await setStorageAt(assetRegistry.address, 201, bh.address)
+
+      decimals = [6, 8, 9, 18]
+
+      tokens = <ERC20MockDecimals[]>(
+        await Promise.all([
+          ERC20Factory.deploy('NAME1', 'TKN1', decimals[0]),
+          ERC20Factory.deploy('NAME2', 'TKN2', decimals[1]),
+          ERC20Factory.deploy('NAME3', 'TKN3', decimals[2]),
+          ERC20Factory.deploy('NAME4', 'TKN4', decimals[3]),
+        ])
+      )
+
+      collateral = <UnpricedCollateral[]>(
+        await Promise.all(tokens.map((t) => UnpricedCollateralFactory.deploy(t.address)))
+      )
+
+      for (let i = 0; i < collateral.length; i++) {
+        await assetRegistry.connect(owner).register(collateral[i].address)
+        await tokens[i].mint(addr1.address, amt)
+        await tokens[i].connect(addr1).approve(rToken.address, amt)
+      }
+
+      // Append a priced collateral
+      tokens.push(erc20s[0])
+      await erc20s[0].connect(addr1).mint(addr1.address, amt)
+      await erc20s[0].connect(addr1).approve(rToken.address, amt)
+
+      // Set basket to 4 UnpricedCollateral + 1 FiatCollateral, all unique targets
+      await bh.connect(owner).setPrimeBasket(
+        tokens.map((t) => t.address),
+        [fp('1'), fp('1'), fp('1'), fp('1'), fp('1')]
+      )
+      await bh.connect(owner).refreshBasket()
+      await advanceTime(Number(config.warmupPeriod) + 1)
+      expect(await rToken.totalSupply()).to.equal(0)
+      expect(await bh.status()).to.equal(CollateralStatus.SOUND)
+      expect(await bh.fullyCollateralized()).to.equal(true)
+    })
+
+    it('collateral interface is correct', async () => {
+      for (let i = 0; i < collateral.length; i++) {
+        expect(await collateral[i].erc20()).to.equal(tokens[i].address)
+        expect(await collateral[i].erc20Decimals()).to.equal(decimals[i])
+        expect(await collateral[i].targetName()).to.equal(
+          ethers.utils.formatBytes32String(`${await tokens[i].symbol()}`)
+        )
+        expect(await collateral[i].status()).to.equal(CollateralStatus.SOUND)
+        expect(await collateral[i].refPerTok()).to.equal(fp('1'))
+        expect(await collateral[i].targetPerRef()).to.equal(fp('1'))
+        expect(await collateral[i].savedPegPrice()).to.equal(fp('0'))
+        expect(await collateral[i].maxTradeVolume()).to.equal(fp('0'))
+        expect(await collateral[i].lastSave()).to.equal(0)
+        expect(await collateral[i].bal(addr1.address)).to.equal(
+          (await tokens[i].balanceOf(addr1.address)).mul(bn('10').pow(18 - decimals[i]))
+        )
+
+        const [low, high] = await collateral[i].price()
+        expect(low).to.equal(0)
+        expect(high).to.equal(MAX_UINT192)
+      }
+    })
+
+    it('should issue and redeem RTokens correctly', async () => {
+      // Issue
+      await rToken.connect(addr1).issue(amt)
+      expect(await rToken.totalSupply()).to.equal(amt)
+      expect(await bh.status()).to.equal(CollateralStatus.SOUND)
+      expect(await bh.fullyCollateralized()).to.equal(true)
+      for (let i = 0; i < collateral.length; i++) {
+        expect(await tokens[i].balanceOf(backingManager.address)).to.equal(
+          toBNDecimals(amt, decimals[i])
+        )
+      }
+
+      // Redeem
+      await rToken.connect(addr1).redeem(amt)
+      expect(await rToken.totalSupply()).to.equal(0)
+      expect(await bh.status()).to.equal(CollateralStatus.SOUND)
+      expect(await bh.fullyCollateralized()).to.equal(true)
+      for (let i = 0; i < collateral.length; i++) {
+        expect(await tokens[i].balanceOf(backingManager.address)).to.equal(0)
+        expect(await tokens[i].balanceOf(addr1.address)).to.equal(amt)
+      }
+    })
+
+    it('should not be able to rebalance because never uncollateralized', async () => {
+      await rToken.connect(addr1).issue(amt)
+      await expect(backingManager.rebalance(0)).to.be.revertedWith('already collateralized')
+      await expect(rTokenAsset.tryPrice()).to.be.revertedWith('invalid price')
+    })
+
+    it('even IF it were to become undercollateralized by way of a hacked token, rebalance STILL should not haircut', async () => {
+      await rToken.connect(addr1).issue(amt)
+      expect(await rToken.basketsNeeded()).to.equal(amt)
+
+      await tokens[0].burn(backingManager.address, 1)
+      expect(await bh.fullyCollateralized()).to.equal(false)
+      await expect(backingManager.rebalance(0)).to.be.revertedWith('BUs unpriced')
+      await expect(rTokenAsset.tryPrice()).to.be.revertedWith('invalid price')
+    })
+
+    it('can coexist with appreciating collateral and process RSR revenue auctions like normal', async () => {
+      const initialStRSRBalance = await rsr.balanceOf(await main.stRSR())
+
+      // Simulate appreciation
+      await tokens[4].mint(backingManager.address, amt)
+      await backingManager.forwardRevenue([tokens[4].address])
+      await rsrTrader.manageTokens([tokens[4].address], [0])
+      expect(await rsrTrader.tradesOpen()).to.equal(1)
+
+      // Bid in dutch auction
+      await advanceTime(config.dutchAuctionLength.toNumber() - 5)
+      const t = await ethers.getContractAt(
+        'DutchTrade',
+        (
+          await getTrade(rsrTrader, tokens[4].address)
+        ).address
+      )
+      await rsr.connect(addr1).mint(addr1.address, amt)
+      await rsr.connect(addr1).approve(t.address, amt)
+      await t.connect(addr1).bid()
+
+      // RSR should have been rewarded
+      expect(await rsr.balanceOf(await main.stRSR())).to.be.gt(initialStRSRBalance)
+    })
+  })
+})