Imports on a containing test class are ignored when a nested class has imports

[wilkinsona]

This was discovered as part of #49854.

This fails:

@WebMvcTest
class ExampleTests {

	@Autowired
	MockMvcTester mvc;

	@Nested
	@Import(Blank.class)
	class NestedExample {

		@Test
		void contextLoads() {

		}


	}
	
	static class Blank {
		
	}

}

@SpringBootTest is also affected:

@SpringBootTest
@AutoConfigureMockMvc
class ExampleTests {

	@Autowired
	MockMvcTester mvc;

	@Nested
	@Import(Blank.class)
	class NestedExample {

		@Test
		void contextLoads() {

		}


	}
	
	static class Blank {
		
	}

}

In either case, the problem doesn't occur if @Import(Blank.class) is removed or if it's moved out onto the containing class.

[wilkinsona]

The examples above do not fail with 3.5.x. They do not fail because two contexts are created, one from the containing class that's used for injection of dependencies into the containing class and one from the nested class that's used for injection of dependencies into the nested class. In 4.0.x, due to a change in the scoping of the extension context in Framework's test context framework, only a single context is created. It's created from the nested class and used for injection of dependencies into both the containing class and the nested class. When we find the @Import on the nested class, we don't search upwards so the import on the containing class is ignored.

This arrangement fails with both 3.5.x and 4.0.x:

@TestPropertySource(properties = "a=alpha")
@Import(ImportedByContainingTests.class)
class SpringBootTestImportTests {

	@Nested
	@SpringBootTest(classes = Config.class)
	@Import(ImportedByNestedTests.class)
	class NestedTests {

		@Autowired(required = false)
		private ImportedByContainingTests importedByContainingTests;

		@Autowired(required = false)
		private ImportedByNestedTests importedByNestedTests;

		@Autowired
		private Environment environment;

		@Test
		void sameClassImportIsHonored() {
			assertThat(this.importedByNestedTests).isNotNull();
		}

		@Test
		void containingClassImportIsHonored() {
			assertThat(this.importedByContainingTests).isNotNull();
		}

		@Test
		void containingClassTestPropertySourceIsHonored() {
			assertThat(this.environment.getProperty("a")).isEqualTo("alpha");
		}

	}

	@Configuration(proxyBeanMethods = false)
	static class Config {

	}

	static class ImportedByNestedTests {

	}

	static class ImportedByContainingTests {

	}

}

The @TestPropertySource on the containing class is honoured and only containingClassImportIsHonored fails. We need to align our @Import behavior with @TestPropertySource by looking at containing classes.