feat: introduce VaultFactory

This commit introduces a first version of a `VaultFactory` that later
will be extended to be capable of instantiating reward vaults and
possible keep track of vault instances per owner.

As a first step, this implementation comes with a `createVault()`
function which takes care of creating vaults.

Because `VaultFactory` also knows about `StakeManager` it can derive the
manager's address and stake token from it when creating vaults, allowing
the API to be without arguments.

Partially addresses #37

contracts/VaultFactory.sol

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.18;
+
+// import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import { Ownable2Step } from "@openzeppelin/contracts/access/Ownable2Step.sol";
+import { StakeManager } from "./StakeManager.sol";
+import { StakeVault } from "./StakeVault.sol";
+
+contract VaultFactory is Ownable2Step {
+    error VaultFactory__InvalidStakeManagerAddress();
+
+    event VaultCreated(address indexed vault, address indexed owner);
+
+    StakeManager public stakeManager;
+
+    constructor(address _stakeManager) {
+        if (_stakeManager == address(0)) {
+            revert VaultFactory__InvalidStakeManagerAddress();
+        }
+        stakeManager = StakeManager(_stakeManager);
+    }
+
+    function setStakeManager(address _stakeManager) external onlyOwner {
+        if (_stakeManager == address(0) || _stakeManager == address(stakeManager)) {
+            revert VaultFactory__InvalidStakeManagerAddress();
+        }
+        stakeManager = StakeManager(_stakeManager);
+    }
+
+    function createVault() external returns (StakeVault) {
+        StakeVault vault = new StakeVault(msg.sender, stakeManager.stakedToken(), stakeManager);
+        emit VaultCreated(address(vault), msg.sender);
+        return vault;
+    }
+}

script/Deploy.s.sol

@@ -4,16 +4,18 @@ pragma solidity >=0.8.19 <=0.9.0;
 import { BaseScript } from "./Base.s.sol";
 import { DeploymentConfig } from "./DeploymentConfig.s.sol";
 import { StakeManager } from "../contracts/StakeManager.sol";
+import { VaultFactory } from "../contracts/VaultFactory.sol";
 
 contract Deploy is BaseScript {
-    function run() public returns (StakeManager, DeploymentConfig) {
+    function run() public returns (VaultFactory, StakeManager, DeploymentConfig) {
         DeploymentConfig deploymentConfig = new DeploymentConfig(broadcaster);
         (, address token) = deploymentConfig.activeNetworkConfig();
 
         vm.startBroadcast(broadcaster);
         StakeManager stakeManager = new StakeManager(token, address(0));
+        VaultFactory vaultFactory = new VaultFactory(address(stakeManager));
         vm.stopBroadcast();
 
-        return (stakeManager, deploymentConfig);
+        return (vaultFactory, stakeManager, deploymentConfig);
     }
 }

test/StakeManager.t.sol

@@ -8,18 +8,20 @@ import { Deploy } from "../script/Deploy.s.sol";
 import { DeploymentConfig } from "../script/DeploymentConfig.s.sol";
 import { StakeManager } from "../contracts/StakeManager.sol";
 import { StakeVault } from "../contracts/StakeVault.sol";
+import { VaultFactory } from "../contracts/VaultFactory.sol";
 
 contract StakeManagerTest is Test {
     DeploymentConfig internal deploymentConfig;
     StakeManager internal stakeManager;
+    VaultFactory internal vaultFactory;
 
     address internal stakeToken;
     address internal deployer;
     address internal testUser = makeAddr("testUser");
 
     function setUp() public virtual {
         Deploy deployment = new Deploy();
-        (stakeManager, deploymentConfig) = deployment.run();
+        (vaultFactory, stakeManager, deploymentConfig) = deployment.run();
         (deployer, stakeToken) = deploymentConfig.activeNetworkConfig();
     }
 
@@ -36,7 +38,7 @@ contract StakeManagerTest is Test {
 
     function _createTestVault(address owner) internal returns (StakeVault vault) {
         vm.prank(owner);
-        vault = new StakeVault(owner, ERC20(stakeToken), stakeManager);
+        vault = vaultFactory.createVault();
 
         vm.prank(deployer);
         stakeManager.setVault(address(vault).codehash);

test/StakeVault.t.sol

@@ -8,12 +8,15 @@ import { Deploy } from "../script/Deploy.s.sol";
 import { DeploymentConfig } from "../script/DeploymentConfig.s.sol";
 import { StakeManager } from "../contracts/StakeManager.sol";
 import { StakeVault } from "../contracts/StakeVault.sol";
+import { VaultFactory } from "../contracts/VaultFactory.sol";
 
 contract StakeVaultTest is Test {
     StakeManager internal stakeManager;
 
     DeploymentConfig internal deploymentConfig;
 
+    VaultFactory internal vaultFactory;
+
     StakeVault internal stakeVault;
 
     address internal deployer;
@@ -24,11 +27,11 @@ contract StakeVaultTest is Test {
 
     function setUp() public virtual {
         Deploy deployment = new Deploy();
-        (stakeManager, deploymentConfig) = deployment.run();
+        (vaultFactory, stakeManager, deploymentConfig) = deployment.run();
         (deployer, stakeToken) = deploymentConfig.activeNetworkConfig();
 
         vm.prank(testUser);
-        stakeVault = new StakeVault(testUser, ERC20(stakeToken), stakeManager);
+        stakeVault = vaultFactory.createVault();
     }
 }
 

test/VaultFactory.t.sol

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.19;
+
+import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+
+import { Test } from "forge-std/Test.sol";
+import { Deploy } from "../script/Deploy.s.sol";
+import { DeploymentConfig } from "../script/DeploymentConfig.s.sol";
+
+import { StakeManager } from "../contracts/StakeManager.sol";
+import { StakeVault } from "../contracts/StakeVault.sol";
+import { VaultFactory } from "../contracts/VaultFactory.sol";
+
+contract VaultFactoryTest is Test {
+    DeploymentConfig internal deploymentConfig;
+
+    StakeManager internal stakeManager;
+
+    VaultFactory internal vaultFactory;
+
+    address internal deployer;
+
+    address internal stakedToken;
+
+    address internal testUser = makeAddr("testUser");
+
+    function setUp() public virtual {
+        Deploy deployment = new Deploy();
+        (vaultFactory, stakeManager, deploymentConfig) = deployment.run();
+        (deployer, stakedToken) = deploymentConfig.activeNetworkConfig();
+    }
+
+    function testDeployment() public {
+        assertEq(address(vaultFactory.stakeManager()), address(stakeManager));
+    }
+}
+
+contract SetStakeManagerTest is VaultFactoryTest {
+    function setUp() public override {
+        VaultFactoryTest.setUp();
+    }
+
+    function test_RevertWhen_InvalidStakeManagerAddress() public {
+        vm.startPrank(deployer);
+        vm.expectRevert(VaultFactory.VaultFactory__InvalidStakeManagerAddress.selector);
+        vaultFactory.setStakeManager(address(0));
+
+        vm.expectRevert(VaultFactory.VaultFactory__InvalidStakeManagerAddress.selector);
+        vaultFactory.setStakeManager(address(stakeManager));
+    }
+
+    function test_SetStakeManager() public {
+        vm.prank(deployer);
+        vaultFactory.setStakeManager(address(this));
+        assertEq(address(vaultFactory.stakeManager()), address(this));
+    }
+}
+
+contract CreateVaultTest is VaultFactoryTest {
+    event VaultCreated(address indexed vault, address indexed owner);
+
+    function setUp() public override {
+        VaultFactoryTest.setUp();
+    }
+
+    function test_createVault() public {
+        vm.prank(testUser);
+        vm.expectEmit(false, false, false, false);
+        emit VaultCreated(makeAddr("some address"), testUser);
+        StakeVault vault = vaultFactory.createVault();
+        assertEq(vault.owner(), testUser);
+        assertEq(address(vault.stakedToken()), address(stakedToken));
+    }
+}