From 78d34929d490b0ba26af038cfed98215cfc75a79 Mon Sep 17 00:00:00 2001
From: Brendan Asselstine <mail.asselstine@gmail.com>
Date: Wed, 18 May 2022 13:53:00 -0700
Subject: [PATCH] Added TokenVault (#266)

---
 contracts/TokenVault.sol | 60 +++++++++++++++++++++++++++++++
 test/TokenVault.test.ts  | 76 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 136 insertions(+)
 create mode 100644 contracts/TokenVault.sol
 create mode 100644 test/TokenVault.test.ts

diff --git a/contracts/TokenVault.sol b/contracts/TokenVault.sol
new file mode 100644
index 00000000..a7575c51
--- /dev/null
+++ b/contracts/TokenVault.sol
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-3.0
+
+pragma solidity 0.8.6;
+
+import "@pooltogether/owner-manager-contracts/contracts/Manageable.sol";
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+
+/**
+    * @title  PoolTogether Vault
+    * @author PoolTogether Inc Team
+ */
+contract Vault is Manageable {
+    using SafeERC20 for IERC20;
+
+    mapping(address => bool) public approved;
+
+    /**
+     * @notice Constructs Vault
+     * @param _owner Owner address
+     */
+    constructor(address _owner) Ownable(_owner) {}
+
+    function setApproved(address _account, bool _approved) external onlyOwner {
+        approved[_account] = _approved;
+    }
+
+    /**
+     * @notice Decrease allowance of ERC20 tokens held by this contract.
+     * @dev Only callable by the owner or asset manager.
+     * @dev Current allowance should be computed off-chain to avoid any underflow.
+     * @param token Address of the ERC20 token to decrease allowance for
+     * @param spender Address of the spender of the tokens
+     * @param amount Amount of tokens to decrease allowance by
+     */
+    function decreaseERC20Allowance(
+        IERC20 token,
+        address spender,
+        uint256 amount
+    ) external onlyManagerOrOwner {
+        token.safeDecreaseAllowance(spender, amount);
+    }
+
+    /**
+     * @notice Increase allowance of ERC20 tokens held by this contract.
+     * @dev Only callable by the owner or asset manager.
+     * @dev Current allowance should be computed off-chain to avoid any overflow.
+     * @param token Address of the ERC20 token to increase allowance for
+     * @param spender Address of the spender of the tokens
+     * @param amount Amount of tokens to increase allowance by
+     */
+    function increaseERC20Allowance(
+        IERC20 token,
+        address spender,
+        uint256 amount
+    ) external onlyManagerOrOwner {
+        require(approved[spender], "Spender must be approved");
+        token.safeIncreaseAllowance(spender, amount);
+    }
+}
diff --git a/test/TokenVault.test.ts b/test/TokenVault.test.ts
new file mode 100644
index 00000000..7dbf2974
--- /dev/null
+++ b/test/TokenVault.test.ts
@@ -0,0 +1,76 @@
+import { SignerWithAddress } from '@nomiclabs/hardhat-ethers/signers';
+import { expect } from 'chai';
+import { deployMockContract } from 'ethereum-waffle';
+import { Contract, Signer } from 'ethers';
+import { ethers, artifacts } from 'hardhat';
+
+const newDebug = require('debug');
+
+const debug = newDebug('pt:Vault.test.ts');
+
+const { getSigners } = ethers;
+
+describe('Vault', () => {
+    let vault: Contract;
+    let token: Contract;
+
+    let wallet1: SignerWithAddress;
+    let wallet2: SignerWithAddress;
+    let wallet3: SignerWithAddress;
+    let wallet4: SignerWithAddress;
+
+    beforeEach(async () => {
+        [wallet1, wallet2, wallet3, wallet4] = await getSigners();
+
+        const IERC20Artifact = await artifacts.readArtifact('IERC20');
+        token = await deployMockContract(wallet1 as Signer, IERC20Artifact.abi);
+
+        const VaultFactory = await ethers.getContractFactory('Vault', wallet1);
+        vault = await VaultFactory.deploy(wallet1.address);
+    });
+
+    describe('constructor', () => {
+        it('should set the owner', async () => {
+            expect(await vault.owner()).to.equal(wallet1.address)
+        })
+    })
+
+    describe('setApproval()', () => {
+        it('should allow the owner to approve accounts', async () => {
+            await vault.setApproved(wallet2.address, true)
+            expect(await vault.approved(wallet2.address)).to.equal(true)
+        })
+    })
+
+    describe('increaseERC20Allowance()', () => {
+        it('should allow owners to increase approval amount', async () => {
+            await vault.setApproved(wallet2.address, true)
+            await token.mock.allowance.withArgs(vault.address, wallet2.address).returns('0')
+            await token.mock.approve.withArgs(wallet2.address, '1111').returns(true)
+            await vault.increaseERC20Allowance(token.address, wallet2.address, '1111')
+        })
+
+        it('should allow managers to increase approval amount', async () => {
+            await vault.setManager(wallet3.address)
+            await vault.setApproved(wallet2.address, true)
+            await token.mock.allowance.withArgs(vault.address, wallet2.address).returns('0')
+            await token.mock.approve.withArgs(wallet2.address, '1111').returns(true)
+            await vault.connect(wallet3).increaseERC20Allowance(token.address, wallet2.address, '1111')
+        })
+    })
+
+    describe('decreaseERC20Allowance()', () => {
+        it('should allow manager to decrease approval amount', async () => {
+            await token.mock.allowance.withArgs(vault.address, wallet2.address).returns('1111')
+            await token.mock.approve.withArgs(wallet2.address, '111').returns(true)
+            await vault.decreaseERC20Allowance(token.address, wallet2.address, '1000')
+        })
+
+        it('should allow manager to decrease approval amount', async () => {
+            await vault.setManager(wallet3.address)
+            await token.mock.allowance.withArgs(vault.address, wallet2.address).returns('1111')
+            await token.mock.approve.withArgs(wallet2.address, '0').returns(true)
+            await vault.connect(wallet3).decreaseERC20Allowance(token.address, wallet2.address, '1111')
+        })
+    })
+});