GH-1213 Fix regression related to removal of TypeTools

Resolves #1213

spring-cloud-function-context/src/test/java/org/springframework/cloud/function/context/catalog/FunctionTypeUtilsTests.java

@@ -17,6 +17,7 @@
 package org.springframework.cloud.function.context.catalog;
 
 
+import java.lang.reflect.Method;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.util.List;
@@ -56,6 +57,12 @@ import static org.assertj.core.api.Assertions.assertThat;
 @SuppressWarnings("unused")
 public class FunctionTypeUtilsTests {
 
+	@Test
+	public void testDiscoverFunctionalMethod() throws Exception {
+		Method method = FunctionTypeUtils.discoverFunctionalMethod(SampleEventConsumer.class);
+		assertThat(method.getName()).isEqualTo("accept");
+	}
+
 	@Test
 	public void testFunctionTypeFrom() throws Exception {
 		Type type = FunctionTypeUtils.discoverFunctionTypeFromClass(SimpleConsumer.class);
@@ -292,4 +299,29 @@ public class FunctionTypeUtilsTests {
 			return inFlux.map(v -> Integer.parseInt(v));
 		}
 	}
+
+	public static abstract class AbstractConsumer<C> implements Consumer<Message<C>> {
+
+		@Override
+		public final void accept(Message<C> message) {
+			if (message == null) {
+				return;
+			}
+
+			doAccept(message.getPayload());
+		}
+
+		protected abstract void doAccept(C payload);
+	}
+
+	public static class SampleEventConsumer extends AbstractConsumer<SampleData> {
+		@Override
+		protected void doAccept(SampleData data) {
+		}
+	}
+
+	public static class SampleData {
+
+	}
+
 }