Allow @DynamicPropertySource on non-static fields

While @DynamicPropertySource is great, it would be even better if it could be executed on each @Test method instead only one time at start of the test class.

For example: okhttp MockWebServer starts on a free random port. But each test needs its own MockWebServer as otherwise the state is preserved between test runs.

@SpringBootTest
public class MockTest implements BeforeEachCallback {
	private MockWebServer mockServer;

	//requires a fresh instance for each @Test method
	@Override
	public void beforeEach(ExtensionContext extensionContext) {
		mockServer = new MockWebServer();
	}

	//this is not possible as mockServer is not static!
	@DynamicPropertySource
	static void changePort(DynamicPropertyRegistry registry) {
		registry.add("my.app.base.url", () -> "http://localhost:" + mockServer.getPort()); 
	}
}

If I’d make the MockWebServer a static field, that won’t work if multiple @Test classes make use of the mock. Eg assertEquals(1, mockServer.getRequestCount()); would only be valid for the first test method, as mockwebserver preserves the state then.

[sbrannen]

Ok, so but testscoped beans have been closed without any implementation?

That’s correct. That issue was bulk closed due to lack of interest.

Is it maybe possible to declare my service that makes use of the “dynamic” @Value("${my.app.base.url}") as test-scoped? So that it rereads the dynamic property from application-context?

That’s what I had in mind. Your use case reminded me of that test-scoped bean proposal.

And your use case would likely be a candidate for re-opening that issue. So feel free to request that it be reopened if you feel strongly about it, and we can revisit the idea.

[membersound]

Ok, so but testscoped beans have been closed without any implementation?

Is it maybe possible to declare my service that makes use of the “dynamic” @Value("${my.app.base.url}") as test-scoped? So that it rereads the dynamic property from application-context?