CODEWITHSUNDEEP
static-methodsjunit4jmockit
Noel Yap
Noel Yap

Reputation: 19758

How to mock out Thread.sleep() with JMockit?

I have the following code:

class Sleeper {
    public void sleep(long duration) {
        try {
            Thread.sleep(duration);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }
}

How do I test, with JMockit, that Thread.currentThread().interrupt() is called if Thread.sleep() throws an InterruptedException?

Upvotes: 6

Views: 4992

Answers (2)

Thunderforge
Thunderforge

Reputation: 20575

As of JMockit 1.43, this is impossible

JMockit 1.43 added this commit, which checks if you are trying to mock a thread and blacklists it. Now you will get this exception:

java.lang.IllegalArgumentException: java.lang.Thread is not mockable

Upvotes: 1

Rogério
Rogério

Reputation: 16380

Interesting question. A bit tricky to test because mocking certain methods of java.lang.Thread can interfere with the JRE or with JMockit itself, and because JMockit is (currently) unable to dynamically mock native methods such as sleep. That said, it can still be done:

public void testResetInterruptStatusWhenInterrupted() throws Exception
{
    new Expectations() {
       @Mocked({"sleep", "interrupt"}) final Thread unused = null;

       {
           Thread.sleep(anyLong); result = new InterruptedException();
           onInstance(Thread.currentThread()).interrupt();
       }
    };

    new Sleeper.sleep();
}

Upvotes: 3

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