Add unit test and filter out synthetic methods

Closes gh-769

Author: sdeleuze

spring-aot/pom.xml

@@ -191,6 +191,11 @@
 			<artifactId>spring-boot-starter-security</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.jetbrains.kotlin</groupId>
+			<artifactId>kotlin-stdlib-jdk8</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 
 	<build>

spring-aot/src/main/java/org/springframework/aot/context/bootstrap/generator/infrastructure/nativex/NativeConfigurationUtils.java

@@ -61,7 +61,7 @@ public static Set<Class<?>> collectTypesInSignature(Method controllerMethod) {
 		Set<Class<?>> collector = new TreeSet<>(Comparator.comparing(Class::getName));
 		Type genericReturnType;
 		Type[] genericParameterTypes;
-		if (KotlinDetector.isSuspendingFunction(controllerMethod)) {
+		if (KotlinDetector.isSuspendingFunction(controllerMethod) && !controllerMethod.isSynthetic()) {
 			Type[] types = controllerMethod.getGenericParameterTypes();
 			ParameterizedType continuation = (ParameterizedType) types[types.length - 1];
 			genericReturnType = ((WildcardType) continuation.getActualTypeArguments()[0]).getLowerBounds()[0];

spring-aot/src/test/java/org/springframework/aot/context/bootstrap/generator/infrastructure/nativex/NativeConfigurationUtilsTests.java

@@ -22,17 +22,20 @@
 import java.util.Map;
 import java.util.Set;
 
+import kotlin.Metadata;
+import kotlin.coroutines.Continuation;
 import org.junit.jupiter.api.Test;
 
 /**
  * Tests for {@link NativeConfigurationUtils}.
  *
  * @author Andy Clement
+ * @author Sebastien Deleuze
  */
 class NativeConfigurationUtilsTests {
 
 	@Test
-	public void typesInSignature() throws NoSuchMethodException, SecurityException, NoSuchFieldException {
+	public void typesInSignatureForMethods() throws NoSuchMethodException, SecurityException, NoSuchFieldException {
 		Set<Class<?>> collected = NativeConfigurationUtils.collectTypesInSignature(this.getClass().getDeclaredMethod("one"));
 		assertThat(collected).containsOnly(Foo.class);
 		collected = NativeConfigurationUtils.collectTypesInSignature(this.getClass().getDeclaredMethod("two", Foo.class));
@@ -41,9 +44,20 @@ public void typesInSignature() throws NoSuchMethodException, SecurityException,
 		assertThat(collected).containsOnly(List.class, Foo.class);
 		collected = NativeConfigurationUtils.collectTypesInSignature(this.getClass().getDeclaredMethod("four", Integer.TYPE, List.class, Map.class));
 		assertThat(collected).containsOnly(Map.class, String.class, List.class, Foo.class, Bar.class, Integer.class);
-		collected = NativeConfigurationUtils.collectTypesInSignature(Boo.class.getDeclaredField("foos"));
+	}
+
+	@Test
+	public void typesInSignatureForFields() throws NoSuchMethodException, SecurityException, NoSuchFieldException {
+		Set<Class<?>> collected = NativeConfigurationUtils.collectTypesInSignature(Boo.class.getDeclaredField("foos"));
 		assertThat(collected).containsOnly(List.class,Foo.class);
 	}
+
+	@Test
+	public void typesInSignatureForSuspendingMethods() throws NoSuchMethodException, SecurityException, NoSuchFieldException {
+		Set<Class<?>> collected = NativeConfigurationUtils.collectTypesInSignature(Baz.class.getDeclaredMethod("greet", Continuation.class));
+		assertThat(collected).containsOnly(Bar.class);
+	}
+
 
 	static class Foo {
 
@@ -71,4 +85,11 @@ static class Boo {
 		List<Foo> foos;
 	}
 
+	@Metadata
+	static class Baz {
+		Object greet(Continuation<? super Bar> completion) {
+			return null;
+		}
+	}
+
 }