Refactor WebTestClient assertions

Rather than returning ExchangeActions that contains ExchangeInfo and
applies a chain of assertions, the exchange operation in WebTestClient
now has an extra step to decode the response.

The outcome of that is ExchangeResult<T>, parameterized with the
decoded body type, and containing the request and response details,
also providing access to built-inassertions via an assertThat()
instance method.

This approach lends itself better to decoding and asserting response
body types with generecis. It is also more friendly to using any
assertion library such as AssertJ since you get the result first
and then deal with assertions.

spring-test/src/test/java/org/springframework/test/web/reactive/server/samples/ErrorTests.java

@@ -18,6 +18,7 @@ package org.springframework.test.web.reactive.server.samples;
 import org.junit.Before;
 import org.junit.Test;
 
+import org.springframework.http.HttpStatus;
 import org.springframework.test.web.reactive.server.WebTestClient;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
@@ -43,14 +44,18 @@ public class ErrorTests {
 	public void notFound() throws Exception {
 		this.client.get().uri("/invalid")
 				.exchange()
-				.assertStatus().isNotFound();
+				.expectNoBody()
+				.assertThat()
+				.status().isNotFound();
 	}
 
 	@Test
 	public void serverException() throws Exception {
 		this.client.get().uri("/server-error")
 				.exchange()
-				.assertStatus().isInternalServerError();
+				.expectNoBody()
+				.assertThat()
+				.status().isEqualTo(HttpStatus.INTERNAL_SERVER_ERROR);
 	}
 
 

spring-test/src/test/java/org/springframework/test/web/reactive/server/samples/HeaderTests.java

@@ -15,8 +15,6 @@
  */
 package org.springframework.test.web.reactive.server.samples;
 
-import java.util.Arrays;
-
 import org.junit.Before;
 import org.junit.Test;
 
@@ -27,8 +25,6 @@ import org.springframework.web.bind.annotation.RequestHeader;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
-import static org.junit.Assert.assertEquals;
-
 /**
  * Tests with custom headers.
  *
@@ -53,17 +49,20 @@ public class HeaderTests {
 	public void requestResponseHeaderPair() throws Exception {
 		this.client.get().uri("/request-response-pair").header("h1", "in")
 				.exchange()
-				.assertStatus().isOk()
-				.assertHeader("h1").isEqualTo("in-out");
+				.expectNoBody()
+				.assertThat()
+				.status().isOk()
+				.header().valueEquals("h1", "in-out");
 	}
 
 	@Test
-	public void headerConsumer() throws Exception {
+	public void headerMultivalue() throws Exception {
 		this.client.get().uri("/multivalue")
 				.exchange()
-				.assertStatus().isOk()
-				.assertHeader("h1").consume(value -> assertEquals("v1", value))
-				.assertHeader("h1").values().consume(values -> assertEquals(Arrays.asList("v1", "v2", "v3"), values));
+				.expectNoBody()
+				.assertThat()
+				.status().isOk()
+				.header().valueEquals("h1", "v1", "v2", "v3");
 	}
 
 

spring-test/src/test/java/org/springframework/test/web/reactive/server/samples/ResponseEntityTests.java

@@ -16,6 +16,7 @@
 package org.springframework.test.web.reactive.server.samples;
 
 import java.net.URI;
+import java.util.Arrays;
 import java.util.LinkedHashMap;
 import java.util.Map;
 
@@ -25,9 +26,12 @@ import org.junit.Before;
 import org.junit.Test;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
+import reactor.test.StepVerifier;
 
+import org.springframework.core.ResolvableType;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
+import org.springframework.test.web.reactive.server.ExchangeResult;
 import org.springframework.test.web.reactive.server.WebTestClient;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
@@ -37,7 +41,6 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 import static org.hamcrest.CoreMatchers.endsWith;
-import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
 import static org.springframework.http.MediaType.TEXT_EVENT_STREAM;
 
@@ -62,37 +65,54 @@ public class ResponseEntityTests {
 	public void entity() throws Exception {
 		this.client.get().uri("/persons/John")
 				.exchange()
-				.assertStatus().isOk()
-				.assertHeaders().contentType(MediaType.APPLICATION_JSON_UTF8)
-				.assertEntity(Person.class).isEqualTo(new Person("John"));
+				.decodeEntity(Person.class)
+				.assertThat()
+				.status().isOk()
+				.header().contentTypeEquals(MediaType.APPLICATION_JSON_UTF8)
+				.bodyEquals(new Person("John"));
 	}
 
 	@Test
 	public void entityList() throws Exception {
 		this.client.get().uri("/persons")
 				.exchange()
-				.assertStatus().isOk()
-				.assertHeaders().contentType(MediaType.APPLICATION_JSON_UTF8)
-				.assertEntity(Person.class).list()
-				.hasSize(3)
-				.contains(new Person("Jane"), new Person("Jason"), new Person("John"));
+				.decodeAndCollect(Person.class)
+				.assertThat()
+				.status().isOk()
+				.header().contentTypeEquals(MediaType.APPLICATION_JSON_UTF8)
+				.bodyEquals(Arrays.asList(new Person("Jane"), new Person("Jason"), new Person("John")));
 	}
 
 	@Test
 	public void entityMap() throws Exception {
+
+		Map<String, Person> map = new LinkedHashMap<>();
+		map.put("Jane", new Person("Jane"));
+		map.put("Jason", new Person("Jason"));
+		map.put("John", new Person("John"));
+
 		this.client.get().uri("/persons?map=true")
 				.exchange()
-				.assertStatus().isOk()
-				.assertEntity(Person.class).map().hasSize(3).containsKeys("Jane", "Jason", "John");
+				.decodeEntity(ResolvableType.forClassWithGenerics(Map.class, String.class, Person.class))
+				.assertThat()
+				.status().isOk()
+				.bodyEquals(map);
 	}
 
 	@Test
 	public void entityStream() throws Exception {
-		this.client.get().uri("/persons").accept(TEXT_EVENT_STREAM)
+
+		ExchangeResult<Flux<Person>> result = this.client.get()
+				.uri("/persons")
+				.accept(TEXT_EVENT_STREAM)
 				.exchange()
-				.assertStatus().isOk()
-				.assertHeaders().contentType(TEXT_EVENT_STREAM)
-				.assertEntity(Person.class).stepVerifier()
+				.decodeFlux(Person.class);
+
+		result.assertThat()
+				.status().isOk()
+				.header().contentTypeEquals(TEXT_EVENT_STREAM);
+
+		StepVerifier.create(result.getResponseBody())
 				.expectNext(new Person("N0"), new Person("N1"), new Person("N2"))
 				.expectNextCount(4)
 				.consumeNextWith(person -> assertThat(person.getName(), endsWith("7")))
@@ -104,17 +124,10 @@ public class ResponseEntityTests {
 	public void postEntity() throws Exception {
 		this.client.post().uri("/persons")
 				.exchange(Mono.just(new Person("John")), Person.class)
-				.assertStatus().isCreated()
-				.assertHeader("location").isEqualTo("/persons/John").and()
-				.assertBody().isEmpty();
-	}
-
-	@Test
-	public void entityConsumer() throws Exception {
-		this.client.get().uri("/persons/John")
-				.exchange()
-				.assertStatus().isOk()
-				.assertEntity(Person.class).consume(p -> assertEquals(new Person("John"), p));
+				.expectNoBody()
+				.assertThat()
+				.status().isCreated()
+				.header().valueEquals("location", "/persons/John");
 	}
 
 

spring-test/src/test/java/org/springframework/test/web/reactive/server/samples/bind/ApplicationContextTests.java

@@ -51,8 +51,10 @@ public class ApplicationContextTests {
 	public void test() throws Exception {
 		this.client.get().uri("/test")
 				.exchange()
-				.assertStatus().isOk()
-				.assertEntity(String .class).isEqualTo("It works!");
+				.decodeEntity(String.class)
+				.assertThat()
+				.status().isOk()
+				.bodyEquals("It works!");
 	}
 
 

spring-test/src/test/java/org/springframework/test/web/reactive/server/samples/bind/ControllerTests.java

@@ -43,8 +43,10 @@ public class ControllerTests {
 	public void test() throws Exception {
 		this.client.get().uri("/test")
 				.exchange()
-				.assertStatus().isOk()
-				.assertEntity(String .class).isEqualTo("It works!");
+				.decodeEntity(String.class)
+				.assertThat()
+				.status().isOk()
+				.bodyEquals("It works!");
 	}
 
 

spring-test/src/test/java/org/springframework/test/web/reactive/server/samples/bind/HttpServerTests.java

@@ -68,8 +68,10 @@ public class HttpServerTests {
 	public void test() throws Exception {
 		this.client.get().uri("/test")
 				.exchange()
-				.assertStatus().isOk()
-				.assertEntity(String .class).isEqualTo("It works!");
+				.decodeEntity(String.class)
+				.assertThat()
+				.status().isOk()
+				.bodyEquals("It works!");
 	}
 
 }

spring-test/src/test/java/org/springframework/test/web/reactive/server/samples/bind/RouterFunctionTests.java

@@ -49,8 +49,10 @@ public class RouterFunctionTests {
 	public void test() throws Exception {
 		this.testClient.get().uri("/test")
 				.exchange()
-				.assertStatus().isOk()
-				.assertEntity(String .class).isEqualTo("It works!");
+				.decodeEntity(String.class)
+				.assertThat()
+				.status().isOk()
+				.bodyEquals("It works!");
 	}
 
 }