GH-1204 Polishing aftre refactoring of TypeTools

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/FunctionRegistration.java

@@ -121,7 +121,7 @@ public class FunctionRegistration<T> implements BeanNameAware {
 		if (KotlinDetector.isKotlinPresent() && this.target instanceof KotlinLambdaToFunctionAutoConfiguration.KotlinFunctionWrapper) {
 			return this;
 		}
-		Type discoveredFunctionType = FunctionTypeUtils.discoverFunctionTypeFromClass(this.target.getClass());
+		Type discoveredFunctionType = type; //FunctionTypeUtils.discoverFunctionTypeFromClass(this.target.getClass());
 		if (discoveredFunctionType == null) { // only valid for Kafka Stream KStream[] return type.
 			return null;
 		}
@@ -146,7 +146,6 @@ public class FunctionRegistration<T> implements BeanNameAware {
 						+ discoveredFunctionType + "; Provided: " + type);
 		}
 
-
 		return this;
 	}
 

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/BeanFactoryAwareFunctionRegistry.java

@@ -180,6 +180,10 @@ public class BeanFactoryAwareFunctionRegistry extends SimpleFunctionRegistry imp
 							else {
 								functionType = FunctionTypeUtils.discoverFunctionType(functionCandidate, functionName, this.applicationContext);
 							}
+
+							if (logger.isDebugEnabled()) {
+								logger.debug("Discovered function type for: " + functionDefinition + " - " + functionType);
+							}
 							if (functionRegistration == null) {
 								functionRegistration = new FunctionRegistration(functionCandidate, functionName).type(functionType);
 							}

spring-cloud-function-context/src/main/java/org/springframework/cloud/function/context/catalog/FunctionTypeUtils.java

@@ -371,7 +371,7 @@ public final class FunctionTypeUtils {
 		else {
 			inputType =  resolvableInputType.getType();
 		}
-		return inputType;
+		return inputType instanceof TypeVariable ? Object.class : inputType;
 	}
 
 	@SuppressWarnings("rawtypes")
@@ -465,7 +465,7 @@ public final class FunctionTypeUtils {
 		else {
 			outputType =  resolvableOutputType.getType();
 		}
-		return outputType;
+		return outputType instanceof TypeVariable ? Object.class : outputType;
 	}
 
 	public static Type getImmediateGenericType(Type type, int index) {

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

@@ -59,7 +59,6 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean
 import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.cloud.function.context.FunctionCatalog;
 import org.springframework.cloud.function.context.FunctionRegistration;
-import org.springframework.cloud.function.context.FunctionRegistry;
 import org.springframework.cloud.function.context.catalog.SimpleFunctionRegistry.FunctionInvocationWrapper;
 import org.springframework.cloud.function.json.JsonMapper;
 import org.springframework.context.ApplicationContext;
@@ -80,7 +79,6 @@ import org.springframework.util.ReflectionUtils;
 
 import static java.util.Collections.singletonList;
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.jupiter.api.Assertions.fail;
 
 /**
  *
@@ -671,46 +669,6 @@ public class BeanFactoryAwareFunctionRegistryTests {
 		assertThat(f.apply(Flux.just(25)).blockFirst()).isEqualTo(25);
 	}
 
-	@SuppressWarnings({ "unchecked", "rawtypes" })
-	@Test
-	public void testRegisteringWithTypeThatDoesNotMatchDiscoveredType() {
-		FunctionCatalog catalog = this.configureCatalog(EmptyConfiguration.class);
-		Function func = catalog.lookup("func");
-		assertThat(func).isNull();
-		FunctionRegistry registry = (FunctionRegistry) catalog;
-		try {
-			FunctionRegistration registration = new FunctionRegistration(new MyFunction(), "a")
-					.type(FunctionTypeUtils.functionType(Integer.class, String.class));
-			registry.register(registration);
-			fail();
-		}
-		catch (IllegalArgumentException e) {
-			// good as we expect it to fail
-		}
-		//
-		try {
-			FunctionRegistration registration = new FunctionRegistration(new MyFunction(), "b")
-					.type(FunctionTypeUtils.functionType(String.class, Integer.class));
-			registry.register(registration);
-			fail();
-		}
-		catch (IllegalArgumentException e) {
-			// good as we expect it to fail
-		}
-		//
-		FunctionRegistration c = new FunctionRegistration(new MyFunction(), "c")
-				.type(FunctionTypeUtils.functionType(String.class, String.class));
-		registry.register(c);
-		//
-		FunctionRegistration d = new FunctionRegistration(new RawFunction(), "d")
-				.type(FunctionTypeUtils.functionType(Person.class, String.class));
-		registry.register(d);
-		//
-		FunctionRegistration e = new FunctionRegistration(new RawFunction(), "e")
-				.type(FunctionTypeUtils.functionType(Object.class, Object.class));
-		registry.register(e);
-	}
-
 	@SuppressWarnings({ "unchecked", "rawtypes" })
 	@Test
 	public void testNoConversionOnInputMapIfInputIsMap() {