Polish

spring-test/src/main/java/org/springframework/test/web/reactive/server/ExchangeResult.java

@@ -231,7 +231,7 @@ public class ExchangeResult {
 		return body
 				.map(bytes -> {
 					if (contentType == null) {
-						return "Unknown content type (" + bytes.length + " bytes)";
+						return bytes.length + " bytes of content (unknown content-type).";
 					}
 					Charset charset = contentType.getCharset();
 					if (charset != null) {
@@ -240,7 +240,7 @@ public class ExchangeResult {
 					if (PRINTABLE_MEDIA_TYPES.stream().anyMatch(contentType::isCompatibleWith)) {
 						return new String(bytes, StandardCharsets.UTF_8);
 					}
-					return "Unknown charset (" + bytes.length + " bytes)";
+					return bytes.length + " bytes of content.";
 				})
 				.defaultIfEmpty("No content")
 				.onErrorResume(ex -> Mono.just("Failed to obtain content: " + ex.getMessage()))

spring-test/src/main/java/org/springframework/test/web/reactive/server/WiretapConnector.java

@@ -24,7 +24,6 @@ import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Function;
 
 import org.reactivestreams.Publisher;
-import org.reactivestreams.Subscription;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.core.publisher.MonoProcessor;
@@ -115,10 +114,8 @@ class WiretapConnector implements ClientHttpConnector {
 
 
 		public ExchangeResult createExchangeResult(Duration timeout, @Nullable String uriTemplate) {
-			return new ExchangeResult(this.request, this.response,
-					Mono.defer(() -> this.request.getRecorder().getContent()),
-					Mono.defer(() -> this.response.getRecorder().getContent()),
-					timeout, uriTemplate);
+			return new ExchangeResult(this.request, this.response, this.request.getRecorder().getContent(),
+					this.response.getRecorder().getContent(), timeout, uriTemplate);
 		}
 	}
 
@@ -137,11 +134,11 @@ class WiretapConnector implements ClientHttpConnector {
 		@Nullable
 		private final Flux<? extends Publisher<? extends DataBuffer>> publisherNested;
 
-		private final DataBuffer buffer;
+		private final DataBuffer buffer = bufferFactory.allocateBuffer();
 
-		private final MonoProcessor<byte[]> content;
+		private final MonoProcessor<byte[]> content = MonoProcessor.create();
 
-		private volatile boolean subscriberRegistered;
+		private boolean hasContentConsumer;
 
 
 		public WiretapRecorder(@Nullable Publisher<? extends DataBuffer> publisher,
@@ -153,22 +150,23 @@ class WiretapConnector implements ClientHttpConnector {
 
 			this.publisher = publisher != null ?
 					Flux.from(publisher)
-							.doOnSubscribe(this::handleOnSubscribe)
-							.doOnNext(this::handleOnNext)
+							.doOnSubscribe(s -> this.hasContentConsumer = true)
+							.doOnNext(this.buffer::write)
 							.doOnError(this::handleOnError)
 							.doOnCancel(this::handleOnComplete)
 							.doOnComplete(this::handleOnComplete) : null;
 
 			this.publisherNested = publisherNested != null ?
 					Flux.from(publisherNested)
-							.doOnSubscribe(this::handleOnSubscribe)
-							.map(p -> Flux.from(p).doOnNext(this::handleOnNext).doOnError(this::handleOnError))
+							.doOnSubscribe(s -> this.hasContentConsumer = true)
+							.map(p -> Flux.from(p).doOnNext(this.buffer::write).doOnError(this::handleOnError))
 							.doOnError(this::handleOnError)
 							.doOnCancel(this::handleOnComplete)
 							.doOnComplete(this::handleOnComplete) : null;
 
-			this.buffer =  bufferFactory.allocateBuffer();
-			this.content = MonoProcessor.create();
+			if (publisher == null && publisherNested == null) {
+				this.content.onComplete();
+			}
 		}
 
 
@@ -183,39 +181,26 @@ class WiretapConnector implements ClientHttpConnector {
 		}
 
 		public Mono<byte[]> getContent() {
-			// No publisher (e.g. request#setComplete)
-			if (this.publisher == null && this.publisherNested == null) {
-				return Mono.empty();
-			}
-			if (this.content.isTerminated()) {
-				return this.content;
-			}
-			if (this.subscriberRegistered) {
-				return Mono.error(new IllegalStateException(
-						"Subscriber registered but content is not yet fully consumed."));
-			}
-			else {
-				// No subscriber, e.g.:
-				// 	- mock server request body never consumed (error before read)
-				//  - FluxExchangeResult#getResponseBodyContent called
-				(this.publisher != null ? this.publisher : this.publisherNested)
-						.onErrorMap(ex -> new IllegalStateException(
-								"Content was not been consumed and " +
-										"an error was raised on attempt to produce it:", ex))
-						.subscribe();
+			return Mono.defer(() -> {
+				if (this.content.isTerminated()) {
+					return this.content;
+				}
+				if (!this.hasContentConsumer) {
+					// Couple of possible cases:
+					//  1. Mock server never consumed request body (e.g. error before read)
+					//  2. FluxExchangeResult: getResponseBodyContent called before getResponseBody
+					//noinspection ConstantConditions
+					(this.publisher != null ? this.publisher : this.publisherNested)
+							.onErrorMap(ex -> new IllegalStateException(
+									"Content was not been consumed and " +
+											"an error was raised on attempt to produce it:", ex))
+							.subscribe();
+				}
 				return this.content;
-			}
+			});
 		}
 
 
-		private void handleOnSubscribe(Subscription subscription) {
-			this.subscriberRegistered = true;
-		}
-
-		private void handleOnNext(DataBuffer nextBuffer) {
-			this.buffer.write(nextBuffer);
-		}
-
 		private void handleOnError(Throwable ex) {
 			if (!this.content.isTerminated()) {
 				this.content.onError(ex);