Motivation

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An extension will be executed only if a class marked the corresponding annotation.  For detailed information, please take a look at the tutorial.

• Test Annotations in

  Interfaces

  interfaces.

Junit5 allows the next annotations in interfaces: 

...

@Test
@DisabledOnEnvironment({"dev", "prod"})
void testFail() {
    fail("this test fails");
}

• Dependency injection for constructors and methods.

Now it becomes available to define parameters for test constructors and methods and use dependency injection for them. With ParameterResolver class we can resolve parameters in runtime. 

At the time of this writing there are 3 built-in parameter resolvers: TestInfo, RepetitionInfo, TestReporter. Example for one of them:

@Test
@DisplayName("Test Get Users")
public void testGetUsersNumberWithInfo(TestInfo testInfo) {
    // test logic.

    logger.info("Running test method:" + testInfo.getTestMethod().get().getName());
}

• Migration Process.

   Migration from JUnit 4 to 5 is not so difficult, as backward compatibility is available.

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1. Migrate examples-module.
   1. Add dependencies to parent/pom.xml
   2. Change adding suites to IgniteExamplesSelfTestSuite. Pay more attention for this point, because @RunWith(JUnitPlatform.class) construction can provide not fully support of all features .
   3. Launch IgniteExamplesMLTestSuite separately under JUnit4, because it is impossible to override JUnitPlatform constructor as well as Suite constructor
   4. Change annotations and imports in test classes
   5. Ignore commented tests
2. Migrate core module in the same way as examples. Classes with dynamic tests do not need to be changed. This is due to the fact that in JUnit5 it is not possible to launch static and dynamic tests under one surefire version. 
   Positive side: the dynamic tests amount is not so big, they locate in specific places. The all JUnit5 opportunity can not be used in dynamic tests (@TestFactory).
   According to the previous points, the next should be added:
   1. Remove test timeouts and add timeouts via annotations
   2. Replace exception checking according to JUnit5 style
   3. Replace some tests on parameterized where it is necessary (the same tests are used with different parameters)
3. Migrate modules where JUnit tests exist. Check list:
   1. aop
   2. aws
   3. camel
   4. cassandra
   5. clients
   6. cloud
   7. comatibility
   8. compress
   9. direct-io
   10. flink
   11. flume
   12. gce
   13. geospastial
   14. hadoop
   15. hibernate 4.2, 5.1, 5.3, core
   16. ignored
   17. indexing
   18. jcl
   19. jta
   20. kafka
   21. kubernates
   22. log4j
   23. log4j2
   24. ml
   25. mqtt
   26. osgi
   27. rest-htpp
   28. rocketmql
   29. schedule
   30. slf4j
   31. spark
   32. spring, spring-data, 2.0
   33. ssh
   34. storm
   35. tensorflow
   36. twitter
   37. urldeploy
   38. web-console
   39. yarn
   40. zeromq
   41. zookeeper

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The community is informed about the migration to 5 and benefits of the newest version.

Additional improvements

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in JUnit 3->4 migration.

Remove JUnit3TestLegacyAssertclass. Replace inheritance to imports

...

Actualize JUnit3TestLegacyAssert class: rename it, update documentation. Replacement inheritance to imports is not appropriate here as it leads to changes of all test classes. Moreover, during migration to the next JUnit versions, problem with changing all test classes will arrise again and in new test classes developer should make import manually.

In JUnit3TestLegacySupport:

1. Investigate replacement of beforeTest/afterTest and beforeTestsStarted/afterTestsStopped methods and if needed replace them by annotations - it is noticed in IGNITE-11413.
2. Replace tearDown, setUp by @BeforeEach, @AfterEach annotations, beforeTest, afterTest methods where it is necessary
3. The same situation with beforeTest, afterTest methods
4. Replace beforeTestsStarted, afterTestsStopped by @BeforeAll, @AfterAll
The rest methods move to GridAbstractTest
5. .
6. Actualize JUnit3TestLegacySupport: remove deprecated annotation, rename class and specify documentation.

Futhermore, GridAbstractTest and GridCommonAbstractTest refactoring necessity should be investigated. Check ability to turn some instance methods to static methods. It was mentioned in the conversation on dev-list.

Risks and Assumptions

• Additional fails on TC because of migration issues
• Performance degradation of tests execution.
  

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