expect.assertions(number) 验证在测试期间调用了一定数量的断言。在测试异步代码时这通常很有用,以便确保回调中的断言确实被调用。 假设我们有一个函数doAsync,它接收两个回调callback1和callback2,它将异步地以一个未知的顺序调用它们。我们可以用: 1 2 3 4 5 6 7 8 9 10 11 test('doAsync calls both ...
Expect主要用于实现验证操作,Jest的Expect提供了如下的验证方法: expect(value) expect.extend(matchers) expect.anything() expect.any(constructor) expect.arrayContaining(array) expect.assertions(number) expect.hasAssertions() expect.not.arrayContaining(array) expect.not.objectContaining(object) expect.not.strin...
expect的参数应该是代码生成的值,而匹配程序的任何参数都应该是正确的值。 expect.extend(matchers) 你可以使用expect.extend将自己的matcher添加到Jest中。例如,假设你正在测试一个 theory library,并且你经常断言数字可以被其他数整除,你可以把它抽象成toBeDivisibleBy matcher。 expect.extend({ toBeDivisibleBy(receive...
异步/等待函数中的Expect.assertions 、、、 来自Jest文档: Expect.assertions(number)验证在测试期间是否调用了一定数量的断言。在测试异步代码时,这通常很有用,以确保回调中的断言确实被调用。这意味着,如果我们正在测试promises的拒绝案例(catch中的断言),那么如果没有expect.assertions promise,那么我们的测试就会通过...
Jest中提供了如下的验证方法: expect(value) expect.extend(matchers) expect.anything() expect.any(constructor) expect.arrayContaining(array) expect.assertions(number) expect.hasAssertions() expect.not.arrayContaining(array) expect.not.objectContaining(object) expect.not.stringContaining(string) expect.not....
你的括号是错误的，直接调用你的函数，它没有被调用。：
expect.hasAssertions() will verify that at least one assertion is called during a test. This is often useful when you are testing asynchronous code, in order to make sure that the assertions in a callback actually got called. For instance, let us say that we have a few functions that al...
When you useexpect, you write assertions similarly to how you would say them, e.g. "I expect this value to be equal to 3" or "I expect this array to contain 3". When you write assertions in this way, you don't need to remember the order of actual and expected arguments to functi...
When an assertion fails, the error message should give as much signal as necessary to the user so they can resolve their issue quickly. You should craft a precise failure message to make sure users of your custom assertions have a good developer experience. ...
expect.hasAssertions()verifies that at least one assertion is called during a test. This is often useful when testing asynchronous code, in order to make sure that assertions in a callback actually got called. For example, let's say that we have a few functions that all deal with state....