Easy way of running the same junit test over and over?
Like the title says, I'm looking for some simple way to run JUnit 4.x tests several times in a row automatically using Eclipse.
An example would be running the same test 10 times in a row and reporting back the result.
We already have a complex way of doing this but I'm looking for a simple way of doing it so that I can be sorta sure that the flaky test I've been trying to fix stays fixed.
An ideal solution would be an Eclipse plugin/setting/feature that I am unaware of.
The easiest (as in least amount of new code required) way to do this is to run the test as a parametrized test (annotate with an @RunWith(Parameterized.class)
and add a method to provide 10 empty parameters). That way the framework will run the test 10 times.
This test would need to be the only test in the class, or better put all test methods should need to be run 10 times in the class.
Here is an example:
@RunWith(Parameterized.class)
public class RunTenTimes {
@Parameterized.Parameters
public static Object[][] data() {
return new Object[10][0];
}
public RunTenTimes() {
}
@Test
public void runsTenTimes() {
System.out.println("run");
}
}
With the above, it is possible to even do it with a parameter-less constructor, but I'm not sure if the framework authors intended that, or if that will break in the future.
If you are implementing your own runner, then you could have the runner run the test 10 times. If you are using a third party runner, then with 4.7, you can use the new @Rule
annotation and implement the MethodRule
interface so that it takes the statement and executes it 10 times in a for loop. The current disadvantage of this approach is that @Before
and @After
get run only once. This will likely change in the next version of JUnit (the @Before
will run after the @Rule
), but regardless you will be acting on the same instance of the object (something that isn't true of the Parameterized
runner). This assumes that whatever runner you are running the class with correctly recognizes the @Rule
annotations. That is only the case if it is delegating to the JUnit runners.
If you are running with a custom runner that does not recognize the @Rule
annotation, then you are really stuck with having to write your own runner that delegates appropriately to that Runner and runs it 10 times.
Note that there are other ways to potentially solve this (such as the Theories runner) but they all require a runner. Unfortunately JUnit does not currently support layers of runners. That is a runner that chains other runners.
With IntelliJ, you can do this from the test configuration. Once you open this window, you can choose to run the test any number of times you want,.
when you run the test, intellij will execute all tests you have selected for the number of times you specified.
Example running 624 tests 10 times: