Implement withdraw function.

.eslintignore

@@ -1,4 +1,7 @@
-cache
-node_modules
-truffle-config.js
+artifacts/
+build/
+cache/
+coverage/
+node_modules/
+
 buidler.config.js

.gitignore

@@ -7,3 +7,9 @@ artifacts
 # Coverage
 coverage
 coverage.json
+
+# Local settings
+config.js
+
+# IDE settings
+.idea/

buidler.config.js

@@ -1,4 +1,7 @@
+const config = require('./config')
+
 usePlugin('@nomiclabs/buidler-waffle')
+usePlugin("@nomiclabs/buidler-etherscan");
 usePlugin('buidler-gas-reporter')
 usePlugin('solidity-coverage')
 
@@ -12,12 +15,9 @@ task('accounts', 'Prints the list of accounts', async () => {
     }
 })
 
-// You have to export an object to set up your config
-// This object can have the following optional entries:
-// defaultNetwork, networks, solc, and paths.
-// Go to https://buidler.dev/config/ to learn more
+// Some of the settings should be defined in `./config.js`.
+// Go to https://buidler.dev/config/ for the syntax.
 module.exports = {
-    // This is a sample solc configuration that specifies which version of solc to use
     solc: {
         version: '0.6.12',
         optimizer: {
@@ -26,9 +26,8 @@ module.exports = {
         },
     },
 
-    networks: {
-        coverage: {
-            url: 'http://localhost:8555'
-        }
-    },
+    defaultNetwork: "buidlerevm",
+
+    networks: config.networks,
+    etherscan: config.etherscan,
 }

config.sample.js

@@ -0,0 +1,34 @@
+module.exports = {
+    networks: {
+        // Needed for `solidity-coverage`
+        coverage: {
+            url: 'http://localhost:8555',
+        },
+
+        // Rinkeby
+        rinkeby: {
+            url: 'https://rinkeby.infura.io/v3/YOUR-INFURA-API-KEY',
+            chainId: 4,
+            accounts: {
+                mnemonic: 'YOUR MNEMONIC HERE',
+                path: 'm/44\'/60\'/0\'/0',
+                initialIndex: 0,
+                count: 10,
+            },
+            gas: 'auto',
+            gasPrice: 1000000000, // 1 gwei
+            gasMultiplier: 1.5,
+        },
+
+        // Mainnet
+        mainnet: {
+            url: 'https://mainnet.infura.io/v3/YOUR-INFURA-API-KEY',
+            chainID: 1,
+        },
+    },
+    // Use to verify contracts on Etherscan
+    // https://buidler.dev/plugins/nomiclabs-buidler-etherscan.html
+    etherscan: {
+        apiKey: 'YOUR-ETHERSCAN-API-KEY',
+    },
+}

contracts/Vault.sol

@@ -31,4 +31,13 @@ contract Vault is Ownable {
     function stakeBalanceOf(address user, address token) public view returns (uint256) {
         return stakes[user][token];
     }
+
+    function withdraw(IERC20 token, address user) public onlyOwner {
+        require(stakes[user][address(token)] > 0, "Vault: User has no stake");
+
+        uint256 stakedAmount = stakes[user][address(token)];
+        stakes[user][address(token)] = 0;
+
+        token.transfer(user, stakedAmount);
+    }
 }

contracts/mocks/ERC20Mock.sol

@@ -6,6 +6,10 @@ import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 contract ERC20Mock is ERC20("ERC20Mock", "MCK") {
     bool public transferFromCalled = false;
 
+    bool public transferCalled = false;
+    address public transferRecipient = address(0);
+    uint256 public transferAmount = 0;
+
     function mint(address user, uint256 amount) public {
         _mint(user, amount);
     }
@@ -15,4 +19,12 @@ contract ERC20Mock is ERC20("ERC20Mock", "MCK") {
 
         return super.transferFrom(sender, recipient, amount);
     }
+
+    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
+        transferCalled = true;
+        transferRecipient = recipient;
+        transferAmount = amount;
+
+        return super.transfer(recipient, amount);
+    }
 }