我写了一个非常简单的合约：

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract Add {
    uint sum = 0;

    address public manager;

    constructor() {
        manager = msg.sender;
    }

    function add(uint num) public restricted returns (uint) {
        sum += num;
        return sum;
    }

    modifier restricted() {
        require (msg.sender == manager, "Can only be executed by the manager");
        _;
    }

}

然后，我使用这个插件进行单元测试，代码也很简单：

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

// This import is automatically injected by Remix
import "remix_tests.sol";

// This import is required to use custom transaction context
// Although it may fail compilation in ’Solidity Compiler ’ plugin
// But it will work fine in ’Solidity Unit Testing ’ plugin
import "remix_accounts.sol";
import "../contracts/Add.sol";

contract AddTest is Add {
    address acc0;
    address acc1;

    function beforeAll() public {
        acc0 = TestsAccounts.getAccount(0);
        acc1 = TestsAccounts.getAccount(1);
    }

    /// #sender: account-0
    function managerTest() public {
        Assert.equal(manager, acc0, "Manager should be acc0"); // 更新断言错误信息
    }

    /// #sender: account-0
    function addTest() public {
        Assert.equal(this.add(2), 2, "You are not Manager!");
    }

}

我在这个测试用例中指定了sender=account-0，但我使用this.add方法调用时，会报错：提示不是管理员无法调用。这是为什么呢？

✘ Add test
Error Message:
"transaction reverted with the reason: Can only be executed by the manager"