Update Cookie headers in MockServerHttpRequest and Response [SPR-15522]

[spring-projects-issues]

Rob Winch opened SPR-15522 and commented

When using the WebTestClient with the mock support (i.e. bindToHttpHandler) cookies are not written as headers to the response like they are when a real server is used. This is illustrated in the tests below.

package sample;

import org.junit.Test;
import org.springframework.http.ResponseCookie;
import org.springframework.http.server.reactive.HttpHandler;
import org.springframework.http.server.reactive.ReactorHttpHandlerAdapter;
import org.springframework.test.web.reactive.server.FluxExchangeResult;
import org.springframework.test.web.reactive.server.WebTestClient;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilter;
import org.springframework.web.server.WebFilterChain;
import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
import reactor.core.publisher.Mono;
import reactor.ipc.netty.NettyContext;

import java.util.Arrays;

import static org.assertj.core.api.Assertions.assertThat;

public class HttpSessionCookieTests {

	// fails
	@Test
	public void createMockWebClient() {
		HttpHandler handler = handler();
		WebTestClient client = WebTestClient.bindToHttpHandler(handler).build();

		assertSetCookieHeaderExists(client);
	}

	// works
	@Test
	public void createReactorNetty() {
		NettyContext netty = null;
		try {
			netty = nettyContext();
			WebTestClient client = WebTestClient.bindToServer()
				.baseUrl("http://localhost:" + netty.address().getPort())
				.build();

			assertSetCookieHeaderExists(client);
		} finally {
			if(netty != null) {
				netty.dispose();
			}
		}
	}

	private HttpHandler handler() {
		return WebHttpHandlerBuilder.webHandler(e -> Mono.empty()).filters(Arrays.asList(new WritesCookieFilter())).build();
	}

	private void assertSetCookieHeaderExists(WebTestClient client) {
		FluxExchangeResult<String> result = client.get()
			.uri("/")
			.exchange()
			.returnResult(String.class);

		assertThat(result.getResponseHeaders()).containsKeys("Set-Cookie");
	}


	private NettyContext nettyContext() {
		HttpHandler handler = handler();
		ReactorHttpHandlerAdapter adapter = new ReactorHttpHandlerAdapter(handler);
		reactor.ipc.netty.http.server.HttpServer httpServer = reactor.ipc.netty.http.server.HttpServer.create("localhost", 0);
		return httpServer.newHandler(adapter).block();
	}

	static class WritesCookieFilter implements WebFilter {

		@Override
		public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
			exchange.getResponse().getCookies().add("FOO", ResponseCookie.from("FOO","BAR").build());
			return chain.filter(exchange);
		}
	}
}

This appears to be related to the fact that AbstractServerHttpResponse relies on applyCookies to be implemented. While ReactorServerHttpResponse implements applyCookies, MockServerHttpResponse does not implement applyCookies.

---

Affects: 5.0 RC1

Issue Links:

• Update Cookie headers in MockHttpServletRequest and Response [SPR-15225] #19790 Update Cookie headers in MockHttpServletRequest and Response

Referenced from: commits 5dcfd84

[spring-projects-issues]

Rossen Stoyanchev commented

I'm wondering if you had noticed this (which does work)?

assertThat(result.getResponseCookies()).containsKeys("Set-Cookie");

The applyXxx methods are for updating underlying request and response abstractions (Netty, Servlet, etc). The mock response doesn't have any. When using the WebTestclient, it's the HttpHandlerConnector copies the cookies from the mock server response to the mock client response.

That said given the recent change in MockServlet[Request|Response] to update headers from cookie objects, we can make a similar change here too.