DisplayNameGenerator cannot access runtime enclosing type for @Nested test class

[sbrannen]

Overview

A DisplayNameGenerator can access the type of a @Nested test class as well as the enclosing class in which a @Nested test class is declared, but it cannot access the concrete type of the enclosing instance for a @Nested test class.

When a DisplayNameGenerator is used to build hierarchical display names, this can lead to confusing results or even conflicting results depending on the structure of the test classes used, "conflicting" in the sense that two nested test classes may have identical display names that do not represent the runtime structure of the test classes.

Example

@IndicativeSentencesGeneration
abstract class AbstractBaseTests {

	@Nested
	class NestedTests {

		@Test
		void test() {
		}
	}
}

class ScenarioOneTests extends AbstractBaseTests {
}

class ScenarioTwoTests extends AbstractBaseTests {
}

Actual Behavior

When running ScenarioOneTests and ScenarioTwoTests, we currently see the following display names.

• ScenarioOneTests
  • AbstractBaseTests, NestedTests
    • AbstractBaseTests, NestedTests, test()
• ScenarioTwoTests
  • AbstractBaseTests, NestedTests
    • AbstractBaseTests, NestedTests, test()

Expected Behavior

When running ScenarioOneTests and ScenarioTwoTests, we would expect the following display names.

• ScenarioOneTests
  • ScenarioOneTests, NestedTests
    • ScenarioOneTests, NestedTests, test()
• ScenarioTwoTests
  • ScenarioTwoTests, NestedTests
    • ScenarioTwoTests, NestedTests, test()

Related Issues

• @DisplayNameGeneration is not discovered on runtime enclosing type for @Nested test class #4131

Deliverables

• Ensure that a DisplayNameGenerator can access the concrete type of the enclosing instance for a @Nested test class.