Testing timeouts with JUnit 4

Overview

In this post, we will discuss the timeout attribute of the @Test method annotation. Testing timeouts in JUnit 4 we need to use the attribute timeout in the @Test(timeout=<value>) annotation. There are other ways to test if the method executes within the specified time, but we will stick to the method-level ( per-test) annotation-based approach here.

Let’s consider that we gonna test whether a method executes within the specified time or not.

Sample Listing

package com.testingdocs.sample;

import org.junit.Test;

public class JUnit4TestClass {
    /* set timeout 3 secs for the method */
   @Test(timeout=3000)
    public void timeOutTest() throws InterruptedException {
        /* Simulate a task that takes 2 secs.
        * 2 < 3 so this method should pass */
      Thread.sleep(2000);
    }
}

 

In the annotation, we have specified 3 secs timeout and simulated a method that takes only 2 secs to complete. Hence, the method should pass in the test result.

 

 

Failure method that exceeds timeout

Now, let us simulate a test failure. We would specify a timeout less than that of the method completion time and check. We have specified timeout as 2 secs and method task 3 secs. The method takes longer tom complete than the timeout.

package com.testingdocs.sample;

import org.junit.Test;

public class JUnit4TestClass {
    /* set timeout 3 secs for the method */
    @Test(timeout=2000)
    public void timeOutTest() throws InterruptedException {
        /* Simulate a task that takes 3 secs.
        * 2 (timeout) < 3 so this method should be marked as
        * a failure */
       Thread.sleep(3000);
    }
}

Class level

To apply the timeout to all the methods you can create a rule as shown below:

package com.testingdocs.sample;

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.Timeout;
import java.util.concurrent.TimeUnit;

public class JUnit4TestClass {

    @Rule
    public Timeout timeout = new Timeout(3000);

    @Test
    public void timeOutTest1() throws InterruptedException {
        Thread.sleep(4000);
    }

    @Test
    public void timeOutTest2() throws InterruptedException {
        Thread.sleep(1000);
    }
}