我正在测试一个作为承诺的一部分返回的函数。我正在使用chai-as-promised。
我能够测试该功能是否有效，但我无法测试它是否正确抛出错误。
我正在尝试测试的功能，省略了许多与承诺相关的代码：
// function that we're trying to test
submitTest = (options) => {
// missingParam is defined elsewhere. It works - the error is thrown if screenshot not passed
if (missingParam(options.screenShot)) throw new Error('Missing parameter');
return {};
}
我的测试：
describe('SpectreClient()', function () {
let client;
before(() => client = SpectreClient('foo', 'bar', testEndpoint));
// the client returns a function, submitTest(), as a part of a promise
/*
omitting tests related to the client
*/
describe('submitTest()', function () {
let screenShot;
before(() => {
screenShot = fs.createReadStream(path.join(__dirname, '/support/test-card.png'));
});
// this test works - it passes as expected
it('should return an object', () => {
const submitTest = client.then((response) => {
return response.submitTest({ screenShot });
});
return submitTest.should.eventually.to.be.a('object');
});
// this test does not work - the error is thrown before the test is evaluated
it('it throws an error if not passed a screenshot', () => {
const submitTest = client.then((response) => {
return response.submitTest({});
});
return submitTest.should.eventually.throw(Error, /Missing parameter/);
});
});
})
测试的输出 -
// console output
1 failing
1) SpectreClient() submitTest() it throws an error if not passed a screenshot:
Error: Missing parameter
如何测试错误是否正确抛出？我不确定这是摩卡咖啡问题还是承诺的事情或 chai-as-promised 的事情。非常感谢帮助。