Schema Builder doesn't support inheriting interface field with subtype (

#2122)

* Add schema-builder tests

* Fix type in comment

* Define Method Ordering in TypeCreator

* Address reviews: Change Map to List of List

common/schema-builder/src/main/java/io/smallrye/graphql/schema/creator/type/TypeCreator.java

@@ -1,11 +1,6 @@
 package io.smallrye.graphql.schema.creator.type;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
+import java.util.*;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -45,28 +40,34 @@ public TypeCreator(ReferenceCreator referenceCreator, FieldCreator fieldCreator,
     @Override
     protected void addFields(Type type, ClassInfo classInfo, Reference reference) {
         // Fields
-        List<MethodInfo> allMethods = new ArrayList<>();
+        List<List<MethodInfo>> allMethods = new LinkedList<>();
         Map<String, FieldInfo> allFields = new HashMap<>();
 
         // Find all methods and properties up the tree
         for (ClassInfo c = classInfo; c != null; c = ScanningContext.getIndex().getClassByName(c.superName())) {
+            List<MethodInfo> listMethods = new ArrayList<>();
+
             if (InterfaceCreator.canAddInterfaceIntoScheme(c.toString())) { // Not java objects
                 List<MethodInfo> classMethods = filterOutBridgeMethod(c.methods());
-                allMethods.addAll(classMethods);
-                allMethods.addAll(getAllInterfaceMethods(c, classMethods
+                listMethods.addAll(getAllInterfaceMethods(c, classMethods
                         .stream()
                         .map(MethodInfo::toString)
                         .collect(Collectors.toSet())));
+                listMethods.addAll(classMethods);
                 for (FieldInfo fieldInfo : c.fields()) {
                     allFields.putIfAbsent(fieldInfo.name(), fieldInfo);
                 }
             }
+
+            allMethods.add(0, listMethods);
         }
-        for (MethodInfo methodInfo : allMethods) {
-            if (MethodHelper.isPropertyMethod(Direction.OUT, methodInfo)) {
-                String fieldName = MethodHelper.getPropertyName(Direction.OUT, methodInfo.name());
-                FieldInfo fieldInfo = allFields.remove(fieldName);
-                fieldCreator.createFieldForPojo(Direction.OUT, fieldInfo, methodInfo, reference).ifPresent(type::addField);
+        for (List<MethodInfo> listMethods : allMethods) {
+            for (MethodInfo methodInfo : listMethods) {
+                if (MethodHelper.isPropertyMethod(Direction.OUT, methodInfo)) {
+                    String fieldName = MethodHelper.getPropertyName(Direction.OUT, methodInfo.name());
+                    FieldInfo fieldInfo = allFields.remove(fieldName);
+                    fieldCreator.createFieldForPojo(Direction.OUT, fieldInfo, methodInfo, reference).ifPresent(type::addField);
+                }
             }
         }
 

common/schema-builder/src/test/java/io/smallrye/graphql/index/SchemaBuilderTest.java

@@ -171,6 +171,28 @@ public void testSchemaWithBatchSourceFieldNameDuplicates() {
         }
     }
 
+    @Test
+    public void testSchemaWithInheritFieldBySubtype() {
+        Indexer indexer = new Indexer();
+        indexDirectory(indexer, "io/smallrye/graphql/index/inherit/");
+
+        IndexView index = indexer.complete();
+        Schema schema = SchemaBuilder.build(index);
+        // Get Types
+        Map<String, Type> types = schema.getTypes();
+        Map<String, Type> interfaces = schema.getInterfaces();
+        Type containerType = types.get("ContainerType");
+        Field containerTypeField = containerType.getFields().get("inheritField");
+        Type containerInterface = interfaces.get("ContainerInterface");
+        Field containerInterfaceField = containerInterface.getFields().get("inheritField");
+
+        // Should be FieldType according to GraphQL Spec: https://spec.graphql.org/October2021/#sec-Objects.Type-Validation
+        assertEquals("io.smallrye.graphql.index.inherit.FieldType",
+                containerTypeField.getReference().getClassName());
+        assertEquals("io.smallrye.graphql.index.inherit.FieldInterface",
+                containerInterfaceField.getReference().getClassName());
+    }
+
     @Test
     public void testSchemaWithDirectives() throws IOException {
         Indexer indexer = new Indexer();

common/schema-builder/src/test/java/io/smallrye/graphql/index/inherit/ContainerInterface.java

@@ -0,0 +1,5 @@
+package io.smallrye.graphql.index.inherit;
+
+public interface ContainerInterface {
+    FieldInterface getInheritField();
+}

common/schema-builder/src/test/java/io/smallrye/graphql/index/inherit/ContainerType.java

@@ -0,0 +1,8 @@
+package io.smallrye.graphql.index.inherit;
+
+public class ContainerType implements ContainerInterface {
+
+    public FieldType getInheritField() {
+        return new FieldType();
+    }
+}

common/schema-builder/src/test/java/io/smallrye/graphql/index/inherit/FieldInterface.java

@@ -0,0 +1,5 @@
+package io.smallrye.graphql.index.inherit;
+
+public interface FieldInterface {
+    String getVal();
+}

common/schema-builder/src/test/java/io/smallrye/graphql/index/inherit/FieldType.java

@@ -0,0 +1,7 @@
+package io.smallrye.graphql.index.inherit;
+
+public class FieldType implements FieldInterface {
+    public String getVal() {
+        return "";
+    }
+}

common/schema-builder/src/test/java/io/smallrye/graphql/index/inherit/InheritAPI.java

@@ -0,0 +1,12 @@
+package io.smallrye.graphql.index.inherit;
+
+import org.eclipse.microprofile.graphql.GraphQLApi;
+import org.eclipse.microprofile.graphql.Query;
+
+@GraphQLApi
+public class InheritAPI {
+    @Query
+    public ContainerInterface getContainer() {
+        return null;
+    }
+}