Allow Inheritance of Multiple Classes and Interfaces for Query and Mutation Classes

src/main/java/graphql/annotations/processor/retrievers/GraphQLObjectInfoRetriever.java

@@ -23,7 +23,9 @@
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.Comparator;
+import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 import static graphql.annotations.processor.util.NamingKit.toGraphqlName;
@@ -36,12 +38,29 @@ public String getTypeName(Class<?> objectClass) {
         return toGraphqlName(name == null ? objectClass.getSimpleName() : name.value());
     }
 
-    public List<Method> getOrderedMethods(Class c) {
-        return Arrays.stream(c.getMethods())
+    public List<Method> getOrderedMethods(Class<?> c) {
+        var methods = new LinkedHashMap<String, Method>();
+        collectMethods(c, methods);
+        return methods.values().stream()
                 .sorted(Comparator.comparing(Method::getName))
                 .collect(Collectors.toList());
     }
 
+    private void collectMethods(Class<?> c, Map<String, Method> methods) {
+        if (c == null) {
+            return;
+        }
+
+        Arrays.stream(c.getDeclaredMethods())
+                .forEach(method -> methods.putIfAbsent(method.getName(), method));
+
+        for (Class<?> iface : c.getInterfaces()) {
+            collectMethods(iface, methods);
+        }
+
+        collectMethods(c.getSuperclass(), methods);
+    }
+
     public Boolean isGraphQLField(AnnotatedElement element) {
         GraphQLField annotation = element.getAnnotation(GraphQLField.class);
         if (annotation == null) {
@@ -50,5 +69,4 @@ public Boolean isGraphQLField(AnnotatedElement element) {
         return annotation.value();
     }
 
-
 }

src/test/java/graphql/annotations/AnnotationsSchemaCreatorTest.java

@@ -96,6 +96,63 @@ public void build_Mutation_SchemaIsCreatedWithMutation() {
         assertThat(mutationType.getFieldDefinitions().size(), is(1));
     }
 
+    public interface BaseQuery {
+        @GraphQLField
+        int baseQuery();
+    }
+
+    public interface IntermediateQuery extends BaseQuery {
+        @GraphQLField
+        int intermediateQuery();
+    }
+
+    public interface InheritedQuery extends IntermediateQuery {
+        @GraphQLField
+        int inheritedQuery();
+    }
+
+    public interface BaseMutation {
+        @GraphQLField
+        int baseMutation();
+    }
+
+    public static class ParentMutation implements BaseMutation {
+        @Override
+        public int baseMutation() {
+            return 6;
+        }
+
+        @GraphQLField
+        public int parentMutation() {
+            return 7;
+        }
+    }
+
+    public static class InheritedMutation extends ParentMutation {
+        @GraphQLField
+        public int inheritedMutation() {
+            return 8;
+        }
+    }
+
+    @Test
+    public void build_QueryAndMutationWithInheritedTypes_SchemaContainsInheritedFields() {
+        // arrange + act
+        GraphQLSchema schema = builder.query(InheritedQuery.class).mutation(InheritedMutation.class).build();
+        GraphQLObjectType queryType = schema.getQueryType();
+        GraphQLObjectType mutationType = schema.getMutationType();
+
+        // assert
+        assertThat(queryType.getFieldDefinition("baseQuery"), notNullValue());
+        assertThat(queryType.getFieldDefinition("intermediateQuery"), notNullValue());
+        assertThat(queryType.getFieldDefinition("inheritedQuery"), notNullValue());
+        assertThat(queryType.getFieldDefinitions().size(), is(3));
+        assertThat(mutationType.getFieldDefinition("baseMutation"), notNullValue());
+        assertThat(mutationType.getFieldDefinition("parentMutation"), notNullValue());
+        assertThat(mutationType.getFieldDefinition("inheritedMutation"), notNullValue());
+        assertThat(mutationType.getFieldDefinitions().size(), is(3));
+    }
+
     public static class SubscriptionTest {
         @GraphQLField
         public int subscribe() {