How to create ExtensionContext for writing tests on an extension

[khmarbaise]

I'm currently in the situation having an extension for JUnit JUpiter which works so far fine..but I'm trying to find a way to create an ExtensionContext as given during the execution of junit jupiter (which is injected into the extension) based on a particular class. The intention is to write some tests which need the ExtensionContext. For example in my extension I have defined:

@Override
public void beforeTestExecution(ExtensionContext context) {
...
}

So the question is: Is there a way to create the ExtensionContext based on a give class for example, having the following test class:

@MavenProfile("profile-on-class")
class ProfileAnnotationOnClass {

  @MavenTest
  void name() {

  }
}

I don't want to really execute the tests I only want to have a correct ExtensionContext which is used for analysing several things like the annotation...
So this would make it possible to write better tests for particular parts of my extension?

[sbrannen]

Is there a way to create the ExtensionContext based on a given class?

No, that's not possible.

You can either mock the ExtensionContext, or you can use the EngineTestKit to execute a single test class or test method.

We recommend using the EngineTestKit to test JUnit Jupiter extensions, and we do that often in our own test suite.

[khmarbaise]

Hi @sbrannen, many thanks for your hints.

Do you have small hint where I can find such examples for using EngineTestKit for extensions?

[sbrannen]

Hi @sbrannen, many thanks for your hints.

You're welcome.

Do you have small hint where I can find such examples for using EngineTestKit for extensions?

There are many examples in JUnit 5's own code base.

However, I'm currently working on Spring and found this one rather quickly:

https://github.com/spring-projects/spring-framework/blob/main/spring-test/src/test/java/org/springframework/test/context/junit/jupiter/DisabledIfAndDirtiesContextTests.java

[khmarbaise]

Many thanks for your hints.