Add Flow to Publisher fallback converter

Author: graemerocher

runtime/src/main/java/io/micronaut/reactive/flow/converters/FlowConverterRegistrar.java

@@ -21,11 +21,13 @@
 import io.reactivex.Flowable;
 import kotlinx.coroutines.flow.Flow;
 import kotlinx.coroutines.reactive.ReactiveFlowKt;
+import org.reactivestreams.Publisher;
 
 import javax.inject.Singleton;
+import java.util.function.Function;
 
 /**
- * Converts between a {@link Flow} and a {@link Flowable}.
+ * Converts between a {@link Flow} and a {@link Publisher}.
  *
  * @author Konrad Kamiński
  * @since 1.3
@@ -36,8 +38,10 @@ public class FlowConverterRegistrar implements TypeConverterRegistrar {
     @Override
     public void register(ConversionService<?> conversionService) {
         // Flow
-        conversionService.addConverter(Flow.class, Flowable.class,
-                flow -> Flowable.fromPublisher(ReactiveFlowKt.asPublisher(flow)));
-        conversionService.addConverter(Flowable.class, Flow.class, ReactiveFlowKt::asFlow);
+        conversionService.addConverter(Flow.class, Flowable.class, (Function<Flow, Flowable>) flow ->
+                Flowable.fromPublisher(ReactiveFlowKt.asPublisher(flow))
+        );
+        conversionService.addConverter(Flow.class, Publisher.class, ReactiveFlowKt::asPublisher);
+        conversionService.addConverter(Publisher.class, Flow.class, ReactiveFlowKt::asFlow);
     }
 }

src/main/docs/guide/introduction/whatsNew.adoc

@@ -4,6 +4,10 @@ Micronaut {version} includes the following changes:
 
 Micronaut now supports creating native-images using GraalVM 19.3.0 for both JDK 8 and JDK 11.
 
+=== Startup and Memory Usage Optimizations
+
+Startup performance and memory usage (20%) have been improved.
+
 === Micronaut Data Integration
 
 Micronaut Data has been added to the `micronaut-bom` and you can now use the CLI to create Micronaut Data projects:
@@ -22,6 +26,12 @@ $ mn create-app myapp --features data-hibernate-jpa
 $ mn create-app myapp --features data-jdbc
 ----
 
+=== Initial Support for Kotlin Coroutines and Flow
+
+Initial support for Kotlin Coroutines and the `Flow` type has been added when used as the return type of controller methods.
+
+Thanks to https://github.com/konrad-kaminski[Konrad Kamiński] for this contribution.
+
 === Immutable `@ConfigurationProperties` and `@EachProperty`
 
 Support for immutable ann:context.annotation.ConfigurationProperties[] has been added by annotating the constructor of any configuration class with ann:context.annotation.ConfigurationInject[]. See the docummentation on <<immutableConfig, Immutable Configuration>> for more information.
@@ -32,6 +42,12 @@ snippet::io.micronaut.docs.config.itfce.EngineConfig[tags="imports,class",indent
 
 https://micronaut-projects.github.io/micronaut-cache/1.0.x/guide/#introduction[Micronaut Cache] has been updated to support https://micronaut-projects.github.io/micronaut-cache/1.0.x/guide/#hazelcast[Hazelcast] and https://micronaut-projects.github.io/micronaut-cache/1.0.x/guide/#ehcache[Ehcache] as additional Cache providers.
 
+=== New Micronaut Jackson XML Module
+
+Support for parsing and serializing to XML has been added with a new https://github.com/micronaut-projects/micronaut-jackson-xml[Jackson XML module].
+
+Thanks to https://github.com/svishnyakoff[Sergey] for this contribution.
+
 === Micronaut OpenAPI (Swagger) 1.3 Update
 
 Micronaut OpenAPI has been updated with loads of improvements including the ability to https://micronaut-projects.github.io/micronaut-openapi/1.3.x/guide/index.html#openApiViews[automatically generate UIs for Swagger output] as part of your application. Thanks to https://github.com/croudet[croudet] for this contribution awesome contribution.