java - 如何对实现 Runnable 的类进行单元测试

Question

我有一个实现 Runnable 接口(interface)的类 ExampleThread。

public class ExampleThread implements Runnable {

    private int myVar;

    public ExampleThread(int var) {
        this.myVar = var;
    }

    @Override
    public void run() {
        if (this.myVar < 0) {
            throw new IllegalArgumentException("Number less than Zero");
        } else {
            System.out.println("Number is " + this.myVar);
        }
    }
}

如何为这个类编写 JUnit 测试。我试过如下

public class ExampleThreadTest {

    @Test(expected = IllegalArgumentException.class)
    public void shouldThrowIllegalArgumentExceptionForInvalidNumber() {
        ExampleThread exThread = new ExampleThread(-1);

        ExecutorService service = Executors.newSingleThreadExecutor();
        service.execute(exThread);
    }
}

但这行不通。有什么方法可以测试这个类以覆盖所有代码吗？

Answer 1

我想您只想测试 run() 方法是否正确。目前，您还测试了 ServiceExecutor。

如果您只想编写单元测试，您应该在测试中调用 run 方法。

public class ExampleThreadTest {

    @Test(expected = IllegalArgumentException.class)
    public void shouldThrowIllegalArgumentExceptionForInvalidNumber() {
        ExampleThread exThread = new ExampleThread(-1);
        exThread.run();
    }
}