Testing Best Practices Java

Intro:

• These are our best practices around unit testing
• They should be followed when writing tests, but exceptions can be made

Best Practices:

• A test should include //given, //when, //then comments, so it is easy to see what is tested
• A test should not test multiple things, i.e. there can be only one when part
• The when part only triggers the code under test; Any lookup for results goes into the then part
• Query tests should assert the results, not only the count of results (exception: the query returns all results)
• If you need to scroll down to see the whole test, consider to break it down
• A test should always have at least one assertion
• Use fluent AssertJ assertions
• If possible, use JUnit 4 conventions (e.g. test rule, ExpectedException rule)
• Write blackbox tests based on public API (Tassilo)
  • Avoid writing tests that rely on internal API (e.g. for preparing a certain state)
  • Avoid testing internal API
• Preferred Annotation order:

@Ignore
@Test
@Deployment(resources = {"testProcess.bpmn"})

• For common test setup and tear down (e.g. services, deployments), use @Before and @After methods
• Use @RequiredHistoryLevel on method or class level, if a test requires a certain history level