407 make FieldResolverScanner prefer concrete methods over interface methods

Author: vojtapol

src/main/kotlin/graphql/kickstart/tools/resolver/FieldResolverScanner.kt

@@ -14,6 +14,7 @@ import graphql.schema.DataFetchingEnvironment
 import org.apache.commons.lang3.ClassUtils
 import org.apache.commons.lang3.reflect.FieldUtils
 import org.slf4j.LoggerFactory
+import java.lang.reflect.Method
 import java.lang.reflect.Modifier
 import java.lang.reflect.Type
 import kotlin.reflect.full.valueParameters
@@ -93,17 +94,20 @@ internal class FieldResolverScanner(val options: SchemaParserOptions) {
         }
     }
 
-    private fun getAllMethods(type: JavaType) =
-        (type.unwrap().declaredNonProxyMethods.toList()
-            + ClassUtils.getAllInterfaces(type.unwrap()).flatMap { it.methods.toList() }
-            + ClassUtils.getAllSuperclasses(type.unwrap()).flatMap { it.methods.toList() })
+    private fun getAllMethods(type: JavaType): List<Method> {
+        val declaredMethods = type.unwrap().declaredNonProxyMethods
+        val superClassesMethods = ClassUtils.getAllSuperclasses(type.unwrap()).flatMap { it.methods.toList() }
+        val interfacesMethods = ClassUtils.getAllInterfaces(type.unwrap()).flatMap { it.methods.toList() }
+
+        return (declaredMethods + superClassesMethods + interfacesMethods)
             .asSequence()
             .filter { !it.isSynthetic }
             .filter { !Modifier.isPrivate(it.modifiers) }
             // discard any methods that are coming off the root of the class hierarchy
             // to avoid issues with duplicate method declarations
             .filter { it.declaringClass != Object::class.java }
             .toList()
+    }
 
     private fun isBoolean(type: GraphQLLangType) = type.unwrap().let { it is TypeName && it.name == Scalars.GraphQLBoolean.name }
 

src/test/groovy/graphql/kickstart/tools/FieldResolverScannerSpec.groovy

@@ -75,6 +75,18 @@ class FieldResolverScannerSpec extends Specification {
         users instanceof MethodFieldResolver
     }
 
+    def "scanner prefers concrete resolver"() {
+        setup:
+        def resolver = new DataClassResolverInfo(Kayak.class)
+
+        when:
+        def meta = scanner.findFieldResolver(new FieldDefinition("information", new TypeName("VehicleInformation")), resolver)
+
+        then:
+        meta instanceof MethodFieldResolver
+        ((MethodFieldResolver) meta).getMethod().getReturnType() == BoatInformation.class
+    }
+
     class RootQuery1 implements GraphQLQueryResolver {
         def field1() {}
     }
@@ -95,11 +107,17 @@ class FieldResolverScannerSpec extends Specification {
         private String name = "name"
     }
 
-    class User {
-
-    }
+    class User {}
 
     class GenericQuery implements GraphQLQueryResolver {
         Connection<User> getUsers() {}
     }
+
+    abstract class Boat implements Vehicle {
+        BoatInformation getInformation() { return this.information; }
+    }
+
+    class BoatInformation implements VehicleInformation {}
+
+    class Kayak extends Boat {}
 }

src/test/groovy/graphql/kickstart/tools/Animal.groovy renamed to src/test/groovy/graphql/kickstart/tools/TestInterfaces.groovy

@@ -1,7 +1,11 @@
 package graphql.kickstart.tools
 
 interface Animal {
-
     SchemaClassScannerSpec.NestedInterfaceTypeQuery.ComplexType type()
+}
 
+interface Vehicle {
+    VehicleInformation getInformation();
 }
+
+interface VehicleInformation {}