[#4] Setup TestExecutor contract

contracts/interfaces/Accounts.sol

@@ -5,5 +5,13 @@ pragma solidity ^0.8.18;
  * @title ISafe Declares the functions that are called on a Safe by Safe protocol.
  */
 interface ISafe {
+
+    function setModule(address _module) external;
 
+    function execTransactionFromModule(
+        address payable to,
+        uint256 value,
+        bytes calldata data,
+        uint8 operation
+    ) external returns (bool success);
 }

contracts/test/TestExecutor.sol

@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: LGPL-3.0-only
+pragma solidity >=0.8.0;
+import {ISafe} from "../interfaces/Accounts.sol";
+
+contract TestExecutor is ISafe {
+    address public module;
+    address[] public owners;
+
+
+    function setModule(address _module) external {
+        module = _module;
+    }
+
+    function exec(address payable to, uint256 value, bytes calldata data) external {
+        bool success;
+        bytes memory response;
+        (success,response) = to.call{value: value}(data);
+        if(!success) {
+            assembly {
+                revert(add(response, 0x20), mload(response))
+            }
+        }
+    }
+
+    function execTransactionFromModule(
+        address payable to,
+        uint256 value,
+        bytes calldata data,
+        uint8 operation
+    ) external returns (bool success) {
+        require(msg.sender == module, "Not authorized");
+        if (operation == 1) (success, ) = to.delegatecall(data);
+        else (success, ) = to.call{value: value}(data);
+    }
+}

test/SafeProtocolMediator.spec.ts

@@ -0,0 +1,21 @@
+import hre from "hardhat";
+import { loadFixture, time } from "@nomicfoundation/hardhat-toolbox/network-helpers";
+import { expect } from "chai";
+import { SignerWithAddress } from "@nomicfoundation/hardhat-ethers/signers";
+
+describe("SafeProtocolMediator", async () => {
+    let deployer: SignerWithAddress, owner: SignerWithAddress, user1: SignerWithAddress, user2: SignerWithAddress;
+
+    async function deployContractFixture() {
+        [deployer, owner, user1, user2]= await hre.ethers.getSigners();
+        const safeProtocolMediator = await (await hre.ethers.getContractFactory("SafeProtocolMediator")).deploy(owner.address);
+        return { safeProtocolMediator };
+    }
+
+    it.only("Should set mediator as a module for a safe", async () => {
+        const safe = await hre.ethers.deployContract("TestExecutor");
+
+        const { safeProtocolMediator } = await loadFixture(deployContractFixture);
+        await safe.setModule(await safeProtocolMediator.getAddress());
+    });
+});