GH-768 Add tests to validate proper map values conversion

Resolves #768

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

@@ -26,6 +26,7 @@ import java.util.Collections;
 import java.util.Date;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
@@ -640,6 +641,16 @@ public class BeanFactoryAwareFunctionRegistryTests {
 		assertThat(resultList).isEmpty();
 	}
 
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	@Test
+	public void testGH_768() throws Exception {
+		FunctionCatalog catalog = this.configureCatalog(SCF_GH_768ConfigurationAsFunction.class);
+		Function function = catalog.lookup("echo");
+
+		String result = (String) function.apply("{\"ricky\":{\"name\":\"ricky\"}}");
+		assertThat(result).isEqualTo("{ricky=Person: ricky/0}");
+	}
+
 	@SuppressWarnings({ "rawtypes", "unchecked" })
 	@Test
 	public void testArrayPayloadOnFluxFunction() throws Exception {
@@ -1117,6 +1128,19 @@ public class BeanFactoryAwareFunctionRegistryTests {
 		}
 	}
 
+	@EnableAutoConfiguration
+	public static class SCF_GH_768ConfigurationAsFunction {
+		@Bean
+		public Function<Map<String, Person>, String> echoToString() {
+			return persons -> {
+				for (Entry<String, Person> entry : persons.entrySet()) {
+					assertThat(entry.getValue().getName()).isNotEmpty(); // would fail if value would not be converted to Person
+				}
+				return persons.toString();
+			};
+		}
+	}
+
 	public static class Person {
 		private String name;
 		private int id;

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

@@ -16,9 +16,12 @@
 
 package org.springframework.cloud.function.context.catalog;
 
+import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
 import java.util.UUID;
 import java.util.function.Consumer;
 import java.util.function.Function;
@@ -120,6 +123,29 @@ public class SimpleFunctionRegistryTests {
 		assertThat(instanceA).isNotSameAs(instanceb).isNotSameAs(instanceC);
 	}
 
+	@Test
+	public void testSCF768() {
+		ResolvableType map = ResolvableType.forClassWithGenerics(Map.class, String.class, Person.class);
+		Type functionType = ResolvableType.forClassWithGenerics(Function.class, map, ResolvableType.forClass(String.class)).getType();
+
+		Function<Map<String, Person>, String> function = persons -> {
+			for (Entry<String, Person> entry : persons.entrySet()) {
+				assertThat(entry.getValue().getName()).isNotEmpty(); // would fail if value would not be converted to Person
+			}
+			return persons.toString();
+		};
+
+		FunctionRegistration<Function<Map<String, Person>, String>> registration = new FunctionRegistration<>(
+				function, "echo").type(FunctionType.of(functionType));
+		SimpleFunctionRegistry catalog = new SimpleFunctionRegistry(this.conversionService, this.messageConverter,
+				new JacksonMapper(new ObjectMapper()));
+		catalog.register(registration);
+
+		FunctionInvocationWrapper lookedUpFunction = catalog.lookup("echo");
+		String result = (String) lookedUpFunction.apply("{\"ricky\":{\"name\":\"ricky\"}}");
+		assertThat(result).isEqualTo("{ricky=ricky}");
+	}
+
 	@Test
 	public void testSCF640() {
 		Echo function = new Echo();
@@ -585,6 +611,11 @@ public class SimpleFunctionRegistryTests {
 		public void setName(String name) {
 			this.name = name;
 		}
+
+		@Override
+		public String toString() {
+			return this.name;
+		}
 	}
 
 	private static class Words implements Supplier<String> {