如何期望与Mocha和Chai投球?

时间:2019-03-27 04:34:28

标签: javascript mocha chai

我找不到用Mocha和Chai捕获抛出的字符串的解决方案

正在测试的代码:

function SimpleDate(year, month, day) {
    if (!isValidDate(year, month, day)) {
        throw "invalid date";
    }
}

测试代码:

it("returns 'invalid date' for year = 2023, month = 13, day = 55", function () {
    let actual = new DateUtils.SimpleDate(2013, 13, 55);
    //let expected ='invalid date';
    let expected = expect(() => DateUtils.SimpleDate(2013, 13, 55)).to.throw('invalid date');


    assert.equal(actual, expected);
});

我希望测试能够通过,但是我尝试过的代码失败,提示'错误:抛出了字符串“无效日期”,抛出了错误:)'

2 个答案:

答案 0 :(得分:1)

最终的解决方案是定义一个包装函数,该函数调用要测试的函数,然后将包装传递给assert.throws

it("returns 'invalid date' for year = 2023, month = 13, day = 55", function () {
    let year = 2013,
        month = 13,
        day = 55;
    let expectedMessage = 'invalid date';
    let wrapper = function () {
        let x = DateUtils.SimpleDate(year, month, day);
    }

    assert.throws(wrapper, expectedMessage);
});

答案 1 :(得分:0)

我相信您应该抛出错误而不是字符串

function SimpleDate(year, month, day) {
        if (!isValidDate(year, month, day)) {
            throw new Error('invalid date');
        }
}