In Eclipse, how do I run a JUnit test case multiple times

Question

I have a unit test that fails sometimes and debugging it is a pain because I don\'t know why it sometimes fails.

Is there a way inside Eclipse that I can run a JUnit

Answer 1

There is a test decorator for this. See Junit API at http://junit.org/apidocs/junit/extensions/RepeatedTest.html

for example

@Test  
@Repeat(10)  
public void FailRandomlyNeedToKnowWhy() {  
    ....
}

Answer 2

I just found the following solution which doesn't require any additional depedency (Spring is required for one of the answers you got).

Run your test with the Parameterized runner:

@RunWith(Parameterized.class)

Then add the following method to provide a number of empty parameters equals to the number of times you want to run the test:

@Parameterized.Parameters
public static List<Object[]> data() {
    return Arrays.asList(new Object[10][0]);
}

This way you don't even have to write a loop. IntelliJ and eclipse also group the results of every iteration together.

Answer 3

Inspired on this solution:

Use @Repeat annotation like this:

public class MyTestClass {

    @Rule
    public RepeatRule repeatRule = new RepeatRule();

    @Test
    @Repeat(10)
    public void testMyCode() {
        //your test code goes here
    }
}

You'll only need these two classes:

Repeat.java:

import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.METHOD;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention( RetentionPolicy.RUNTIME )
@Target({ METHOD, ANNOTATION_TYPE })
public @interface Repeat {
    int value() default 1;
}

RepeatRule.java:

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

public class RepeatRule implements TestRule {

    private static class RepeatStatement extends Statement {
        private final Statement statement;
        private final int repeat;    

        public RepeatStatement(Statement statement, int repeat) {
            this.statement = statement;
            this.repeat = repeat;
        }

        @Override
        public void evaluate() throws Throwable {
            for (int i = 0; i < repeat; i++) {
                statement.evaluate();
            }
        }

    }

    @Override
    public Statement apply(Statement statement, Description description) {
        Statement result = statement;
        Repeat repeat = description.getAnnotation(Repeat.class);
        if (repeat != null) {
            int times = repeat.value();
            result = new RepeatStatement(statement, times);
        }
        return result;
    }
}

2016-10-25 Edit: In order to use this solution when using @RunWith(PowerMockRunner.class), update to Powermock 1.6.5 (which includes this patch).

Answer 4

Have you tried something like this?

@Test
public void runMultipleTests() {
    for (int i = 0; i < 10; i++) {
        myTestMethod();
    }
}