Support for reactive types in Conventions

Issue: SPR-14915

spring-core/src/test/java/org/springframework/core/ConventionsTests.java

@@ -16,14 +16,23 @@
 
 package org.springframework.core;
 
+import java.lang.reflect.Method;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
+import java.util.Set;
 
+import io.reactivex.Observable;
+import io.reactivex.Single;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
 
 import org.springframework.tests.sample.objects.TestObject;
+import org.springframework.util.ClassUtils;
 
 import static org.junit.Assert.assertEquals;
 
@@ -41,8 +50,15 @@ public class ConventionsTests {
 
 	@Test
 	public void simpleObject() {
+
 		assertEquals("Incorrect singular variable name",
 				"testObject", Conventions.getVariableName(new TestObject()));
+
+		assertEquals("Incorrect singular variable name", "testObject",
+				Conventions.getVariableNameForParameter(getMethodParameter(TestObject.class)));
+
+		assertEquals("Incorrect singular variable name", "testObject",
+				Conventions.getVariableNameForReturnType(getMethodForReturnType(TestObject.class)));
 	}
 
 	@Test
@@ -53,8 +69,15 @@ public class ConventionsTests {
 
 	@Test
 	public void list() {
+
 		assertEquals("Incorrect plural List form", "testObjectList",
 				Conventions.getVariableName(Collections.singletonList(new TestObject())));
+
+		assertEquals("Incorrect plural List form", "testObjectList",
+				Conventions.getVariableNameForParameter(getMethodParameter(List.class)));
+
+		assertEquals("Incorrect plural List form", "testObjectList",
+				Conventions.getVariableNameForReturnType(getMethodForReturnType(List.class)));
 	}
 
 	@Test
@@ -65,8 +88,47 @@ public class ConventionsTests {
 
 	@Test
 	public void set() {
+
 		assertEquals("Incorrect plural Set form", "testObjectList",
 				Conventions.getVariableName(Collections.singleton(new TestObject())));
+
+		assertEquals("Incorrect plural Set form", "testObjectList",
+				Conventions.getVariableNameForParameter(getMethodParameter(Set.class)));
+
+		assertEquals("Incorrect plural Set form", "testObjectList",
+				Conventions.getVariableNameForReturnType(getMethodForReturnType(Set.class)));
+	}
+
+	@Test
+	public void reactiveParameters() throws Exception {
+
+		assertEquals("testObjectMono",
+				Conventions.getVariableNameForParameter(getMethodParameter(Mono.class)));
+
+		assertEquals("testObjectFlux",
+				Conventions.getVariableNameForParameter(getMethodParameter(Flux.class)));
+
+		assertEquals("testObjectSingle",
+				Conventions.getVariableNameForParameter(getMethodParameter(Single.class)));
+
+		assertEquals("testObjectObservable",
+				Conventions.getVariableNameForParameter(getMethodParameter(Observable.class)));
+	}
+
+	@Test
+	public void reactiveReturnTypes() throws Exception {
+
+		assertEquals("testObjectMono",
+				Conventions.getVariableNameForReturnType(getMethodForReturnType(Mono.class)));
+
+		assertEquals("testObjectFlux",
+				Conventions.getVariableNameForReturnType(getMethodForReturnType(Flux.class)));
+
+		assertEquals("testObjectSingle",
+				Conventions.getVariableNameForReturnType(getMethodForReturnType(Single.class)));
+
+		assertEquals("testObjectObservable",
+				Conventions.getVariableNameForReturnType(getMethodForReturnType(Observable.class)));
 	}
 
 	@Test
@@ -84,4 +146,48 @@ public class ConventionsTests {
 		assertEquals(desiredResult, Conventions.getQualifiedAttributeName(cls, baseName));
 	}
 
+
+	private static MethodParameter getMethodParameter(Class<?> parameterType) {
+		Method method = ClassUtils.getMethod(TestBean.class, "handle", (Class<?>[]) null);
+		for (int i=0; i < method.getParameterCount(); i++) {
+			if (parameterType.equals(method.getParameterTypes()[i])) {
+				return new MethodParameter(method, i);
+			}
+		}
+		throw new IllegalArgumentException("Parameter type not found: " + parameterType);
+	}
+
+	private static Method getMethodForReturnType(Class<?> returnType) {
+		return Arrays.stream(TestBean.class.getMethods())
+				.filter(method -> method.getReturnType().equals(returnType))
+				.findFirst()
+				.orElseThrow(() ->
+						new IllegalArgumentException("Unique return type not found: " + returnType));
+	}
+
+
+	@SuppressWarnings("unused")
+	private static class TestBean {
+
+		public void handle(TestObject to,
+				List<TestObject> toList, Set<TestObject> toSet,
+				Mono<TestObject> toMono, Flux<TestObject> toFlux,
+				Single<TestObject> toSingle, Observable<TestObject> toObservable) { }
+
+		public TestObject handleTo() { return null; }
+
+		public List<TestObject> handleToList() { return null; }
+
+		public Set<TestObject> handleToSet() { return null; }
+
+		public Mono<TestObject> handleToMono() { return null; }
+
+		public Flux<TestObject> handleToFlux() { return null; }
+
+		public Single<TestObject> handleToSingle() { return null; }
+
+		public Observable<TestObject> handleToObservable() { return null; }
+
+	}
+
 }