如何对使用Java UUID的代码进行单元测试？ [英] How do I unit test code which uses Java UUID?

问题描述

我有一段代码，预计会用Java UUID（ UUID.randomUUID（））填充响应对象的一个​​属性。

I have a piece of code which is expected to populated one attribute of response object with Java UUID (UUID.randomUUID()).

如何从外部对此代码进行单元测试以检查此行为？我不知道将在其中生成的UUID。

How can I unit test this code from outside to check this behaviour? I don't know the UUID that would be generated inside it.

需要测试的示例代码：

// To test whether x attribute was set using an UUID
// instead of hardcode value in the response
class A {
  String x;
  String y;
}

// Method to test
public A doSomething() {
  // Does something
  A a = new A();
  a.setX( UUID.randomUUID());
  return a;
}

推荐答案

Powermock和静态模拟是前进的方向。你需要这样的东西：

Powermock and static mocking is the way forward. You will need something like:

    ...
    import static org.junit.Assert.assertEquals;
    import static org.powermock.api.mockito.PowerMockito.mockStatic;
    ...

    @PrepareForTest({ UUID.class })
    @RunWith(PowerMockRunner.class)
    public class ATest
    {
    ...
      //at some point in your test case you need to create a static mock
      mockStatic(UUID.class);
      when(UUID.randomUUID()).thenReturn("your-UUID");
    ...
    }

注意静态模拟可以在一个实现使用@Before注释的方法，因此它可以在需要UUID的所有测试用例中重复使用，以避免代码重复。

Note the static mock can be implemented in a method annotated with @Before so it can be re-used in all test cases that require UUID in order to avoid code repetition.

初始化静态模拟后，值可以在测试方法的某个地方声明UUID，如下所示：

Once the static mock is initialised, the value of UUID can be asserted somewhere in your test method as follows:

A a = doSomething();
assertEquals("your-UUID", a.getX());

这篇关于如何对使用Java UUID的代码进行单元测试？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！