How to Rerun Failed Tests with JUnit?

Sometimes due to some temporary problems such as connection problems, server problems, browser issues, mobile application crashes and freezes, and so on our tests fail. In these kinds of situations, we may want to rerun our tests automatically.

But how? We can handle this with test frameworks such as TestNG and JUnit and in this post, I want to show you how to rerun failed tests with JUnit 4.

Also, you can do the same operation with TestNG. It is a great test framework and actually more QA-friendly. In another post, I will also explain how to do the same operation with TestNG using several ways. Especially, you can handle many situations with TestNG Listeners and this is another post topic. Rerun Tests

In my Junit Rules post, I described how to write Custom Rules and I showed a sample custom ScreenShot Rule implementation.  In this post, we will create a similar custom Rule class that implements TestRule class.  We need to override evaluate() method and write retry logic in it.

Rerun Failed Tests with JUnit 4 Example Rerun Tests JUnit

We need two classes, one of them is our Rule Class’s RetryRule and the other is our Test Class’s RetryRuleTest.

In RetryRuleTest class, I will open www.swtestacademy.com and get its title and check it with the WRONG expected title. Thus, our test will fail and I will expect that our test rerun according to the given retry count argument. I set the retry count as 3 in our example.

RetryRule Class

package junit4rerun;

import java.util.Objects;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;

public class RetryRule implements TestRule {
    private int retryCount;

    public RetryRule(int retryCount) {
        this.retryCount = retryCount;
    }

    public Statement apply(Statement base, Description description) {
        return statement(base, description);
    }

    private Statement statement(final Statement base, final Description description) {
        return new Statement() {
            @Override
            public void evaluate() throws Throwable {
                Throwable caughtThrowable = null;
                // implement retry logic here
                for (int i = 0; i < retryCount; i++) {
                    try {
                        base.evaluate();
                        return;
                    }
                    catch (Throwable t) {
                        caughtThrowable = t;
                        System.err.println(description.getDisplayName() + ": run " + (i + 1) + " failed.");
                    }
                }
                System.err.println(description.getDisplayName() + ": Giving up after " + retryCount + " failures.");
                throw Objects.requireNonNull(caughtThrowable);
            }
        };
    }
}

RetryRuleTest Class

package junit4rerun;

import static org.hamcrest.MatcherAssert.assertThat;

import io.github.bonigarcia.wdm.WebDriverManager;
import org.hamcrest.CoreMatchers;
import org.junit.BeforeClass;
import org.junit.Rule;
import org.junit.Test;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;

public class RetryRuleTest {
    static        WebDriver driver;
    final private String    URL = "https:";

    @BeforeClass
    public static void setupTest() {
        WebDriverManager.chromedriver().setup();
        driver = new ChromeDriver();
    }

    //Set retry count argument
    @Rule
    public RetryRule retryRule = new RetryRule(3);

    @Test
    public void getURLExample() {
        driver.get(URL);
        assertThat(driver.getTitle(), CoreMatchers.is("WRONG TITLE"));
    }
}

Results

GitHub Project

https://github.com/swtestacademy/selenium-examples/tree/main/src/test/java/junit4rerun

Thanks.
Onur Baskirt

Onur Baskirt

Onur Baskirt is a Software Engineering Leader with international experience in world-class companies. Now, he is a Software Engineering Lead at Emirates Airlines in Dubai.