在dart中测试PODO构造函数异常

Question

这是我的构造函数：

Merchant(
  this._firstName,
  this._lastName,
  this._company,
  this._buildingNumber,
  this._location,
  this._city,
  String pin,
  String phone,
  String email,
  this._image) {
  _validatePin(pin) ? _pin = pin : throw pinFormatException;
  _validatePhone(phone) ? _phone = phone : throw phoneFormatException;
  _validateEmail(email) ? _email = email : throw emailFormatException;
}

我想对这个构造函数进行单元测试。我想测试在数据验证失败时抛出正确的异常。我要密码是6位数。所以，这就是我为它写的测试：

test('pin must be a 6-digit number', () {
  expect(() {
    new Merchant(FIRST_NAME, LAST_NAME, COMPANY, BUILDING_NUMBER, LOCATION,
        CITY, 1234567/*PIN*/, WHATSAPP_NUMBER, EMAIL, IMAGE_RESOURCE);
  }, throwsA(Exception));
});

我想知道如何正确地使用throwsA()函数来确保抛出正确异常消息的正确异常。

这是我在运行上面的测试时遇到的错误：

​

Expected: throws ?:<Exception>
  Actual: <Closure: () => dynamic>
   Which: threw ?:<Exception: pin codes are 6-digit numbers>
          stack package:mnshi/model/merchant.dart 33:38                                              new Merchant
                /home/raveesh/MyCode/code/production/mnshi/test/cli_tests/merchant_tests.dart 27:21  main.<fn>.<fn>.<fn>
                package:test                                                                         expect
                /home/raveesh/MyCode/code/production/mnshi/test/cli_tests/merchant_tests.dart 27:7   main.<fn>.<fn>

package:test                             expect
test/cli_tests/merchant_tests.dart 27:7  main.<fn>.<fn>

​

请帮帮忙！

Answer 1

关闭！throwA实际上是另一个Matcher，而不是Type。

假设您有一些扩展FormatException的内容，您可以编写：

expect(() {
  ...
}, throwsFormatException);

如果您不这样做，您可以自己制作一种复合匹配器：

final throwsException = throwsA(const isInstanceOf<Exception>());

...

expect(() {
  ... 
}, throwsException);

其原因是您可以编写不同的组合匹配器。例如，这里有一个检查是否抛出具有.toString() of 'Bad thing occured'的东西

expect(() {
  ...
}, throwsA(predicate((e) => e.toString().contains('Bad thing'));

您可以在这里了解更多关于matchers的信息：

• https://github.com/dart-lang/test#asynchronous-tests
• https://www.dartdocs.org/documentation/matcher/0.12.1%2B4/matcher/matcher-library.html