Add support @Target annotation

.gitignore

@@ -7,6 +7,7 @@ formatter-maven-cache.properties
 
 # ignore Gradle generated build folders
 build
+bin
 
 # ignore downloaded maven
 /tools/maven

common/schema-builder/src/main/java/io/smallrye/graphql/schema/Annotations.java

@@ -593,6 +593,7 @@ private static Map<DotName, AnnotationInstance> getAnnotationsWithFilter(org.jbo
     public static final DotName DATAFETCHER = DotName.createSimple("io.smallrye.graphql.api.DataFetcher");
     public static final DotName SUBCRIPTION = DotName.createSimple("io.smallrye.graphql.api.Subscription");
     public static final DotName RESOLVER = DotName.createSimple("io.smallrye.graphql.api.federation.Resolver");
+    public static final DotName TARGET = DotName.createSimple("io.smallrye.graphql.api.Target");
     public static final DotName DIRECTIVE = DotName.createSimple("io.smallrye.graphql.api.Directive");
     public static final DotName DEFAULT_NON_NULL = DotName.createSimple("io.smallrye.graphql.api.DefaultNonNull");
     public static final DotName NULLABLE = DotName.createSimple("io.smallrye.graphql.api.Nullable");

common/schema-builder/src/main/java/io/smallrye/graphql/schema/SchemaBuilder.java

@@ -114,8 +114,8 @@ private SchemaBuilder(TypeAutoNameStrategy autoNameStrategy) {
         referenceCreator = new ReferenceCreator(autoNameStrategy);
         fieldCreator = new FieldCreator(referenceCreator);
         argumentCreator = new ArgumentCreator(referenceCreator);
-        inputTypeCreator = new InputTypeCreator(fieldCreator);
         operationCreator = new OperationCreator(referenceCreator, argumentCreator);
+        inputTypeCreator = new InputTypeCreator(fieldCreator, operationCreator);
         typeCreator = new TypeCreator(referenceCreator, fieldCreator, operationCreator);
         interfaceCreator = new InterfaceCreator(referenceCreator, fieldCreator, operationCreator);
         directiveTypeCreator = new DirectiveTypeCreator(referenceCreator);

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

@@ -75,7 +75,9 @@ public Optional<Argument> createArgument(Operation operation, MethodInfo methodI
                 .orElse(defaultName);
 
         Reference reference;
-        if (isSourceAnnotationOnSourceOperation(annotationsForThisArgument, operation)) {
+        boolean sourceArgument = isSourceAnnotationOnSourceOperation(annotationsForThisArgument, operation);
+
+        if (sourceArgument) {
             reference = referenceCreator.createReferenceForSourceArgument(argumentType, annotationsForThisArgument);
         } else if (!argumentType.name().equals(CONTEXT)) {
             reference = referenceCreator.createReferenceForOperationArgument(argumentType, annotationsForThisArgument);
@@ -89,9 +91,7 @@ public Optional<Argument> createArgument(Operation operation, MethodInfo methodI
                 name,
                 reference);
 
-        if (isSourceAnnotationOnSourceOperation(annotationsForThisArgument, operation)) {
-            argument.setSourceArgument(true);
-        }
+        argument.setSourceArgument(sourceArgument);
 
         if (validationHelper != null) {
             List<DirectiveInstance> constraintDirectives = validationHelper

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

@@ -1,6 +1,7 @@
 package io.smallrye.graphql.schema.creator;
 
 import java.lang.reflect.Modifier;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
@@ -17,6 +18,7 @@
 import io.smallrye.graphql.schema.Classes;
 import io.smallrye.graphql.schema.SchemaBuilderException;
 import io.smallrye.graphql.schema.helper.DeprecatedDirectivesHelper;
+import io.smallrye.graphql.schema.helper.DescriptionHelper;
 import io.smallrye.graphql.schema.helper.Direction;
 import io.smallrye.graphql.schema.helper.MethodHelper;
 import io.smallrye.graphql.schema.helper.RolesAllowedDirectivesHelper;
@@ -25,6 +27,7 @@
 import io.smallrye.graphql.schema.model.Operation;
 import io.smallrye.graphql.schema.model.OperationType;
 import io.smallrye.graphql.schema.model.Reference;
+import io.smallrye.graphql.schema.model.Wrapper;
 import kotlin.metadata.Attributes;
 import kotlin.metadata.KmClassifier;
 import kotlin.metadata.KmFunction;
@@ -113,6 +116,45 @@ public Operation createOperation(MethodInfo methodInfo, OperationType operationT
         return operation;
     }
 
+    /**
+     * Creates an operation that is exposed as an input field by @Target.
+     */
+    public Operation createTargetOperation(MethodInfo methodInfo, Reference targetFieldOn) {
+        if (!Modifier.isPublic(methodInfo.flags())) {
+            throw new IllegalArgumentException(
+                    "Method " + methodInfo.declaringClass().name().toString() + "#" + methodInfo.name()
+                            + " is used as a target input field, but is not public");
+        }
+
+        short[] parameterPositions = getTargetParameterPositions(methodInfo);
+        short targetPosition = parameterPositions[0];
+        short valuePosition = parameterPositions[1];
+
+        Type valueType = methodInfo.parameterType(valuePosition);
+        Annotations annotationsForMethod = Annotations.getAnnotationsForMethod(methodInfo);
+        Annotations annotationsForValue = Annotations.getAnnotationsForArgument(methodInfo, valuePosition);
+
+        String name = getTargetFieldName(methodInfo, annotationsForMethod);
+        Reference reference = referenceCreator.createReferenceForOperationArgument(valueType, annotationsForValue);
+
+        Operation operation = new Operation(methodInfo.declaringClass().name().toString(),
+                methodInfo.name(),
+                name,
+                name,
+                reference,
+                null,
+                null);
+        operation.setTargetFieldOn(targetFieldOn);
+        operation.setParameterClassNames(getParameterClassNames(methodInfo));
+        operation.setTargetParameterPosition(targetPosition);
+        operation.setValueParameterPosition(valuePosition);
+
+        populateField(Direction.IN, operation, valueType, annotationsForValue);
+        DescriptionHelper.getDescriptionForField(annotationsForMethod, valueType).ifPresent(operation::setDescription);
+
+        return operation;
+    }
+
     // If the operation return type is a wrapper and is written in Kotlin,
     // this checks whether the wrapped type is nullable.
     // Nullability metadata is stored in the kotlin.Metadata annotation
@@ -294,6 +336,51 @@ private static String getOperationName(MethodInfo methodInfo, OperationType oper
 
     }
 
+    private short[] getTargetParameterPositions(MethodInfo methodInfo) {
+        short targetPosition = -1;
+        short valuePosition = -1;
+        int targetCount = 0;
+        int valueCount = 0;
+        for (short i = 0; i < methodInfo.parametersCount(); i++) {
+            Annotations annotations = Annotations.getAnnotationsForArgument(methodInfo, i);
+            if (annotations.containsOneOfTheseAnnotations(Annotations.TARGET)) {
+                targetPosition = i;
+                targetCount++;
+            } else if (!methodInfo.parameterType(i).name().equals(CONTEXT)) {
+                valuePosition = i;
+                valueCount++;
+            }
+        }
+        if (targetCount != 1 || valueCount != 1) {
+            throw new SchemaBuilderException("Target input field method [" + methodInfo.declaringClass().name()
+                    + "#" + methodInfo.name() + "] must declare exactly one @Target parameter and one input value parameter");
+        }
+        return new short[] { targetPosition, valuePosition };
+    }
+
+    private List<String> getParameterClassNames(MethodInfo methodInfo) {
+        List<String> parameterClassNames = new ArrayList<>();
+        for (Type parameterType : methodInfo.parameterTypes()) {
+            parameterClassNames.add(getParameterClassName(parameterType));
+        }
+        return parameterClassNames;
+    }
+
+    private String getParameterClassName(Type parameterType) {
+        return WrapperCreator.createWrapper(parameterType)
+                .map(Wrapper::getWrapperClassName)
+                .orElse(parameterType.name().toString());
+    }
+
+    private static String getTargetFieldName(MethodInfo methodInfo, Annotations annotations) {
+        return annotations.getOneOfTheseMethodAnnotationsValue(
+                Annotations.NAME,
+                Annotations.JAKARTA_JSONB_PROPERTY,
+                Annotations.JAVAX_JSONB_PROPERTY,
+                Annotations.JACKSON_PROPERTY)
+                .orElse(methodInfo.name());
+    }
+
     private static DotName getOperationAnnotation(OperationType operationType) {
         switch (operationType) {
             case QUERY:
@@ -372,4 +459,6 @@ private void addDirectiveForDeprecated(Annotations annotationsForOperation, Oper
     public String getDirectiveLocation() {
         return "FIELD_DEFINITION";
     }
+
+    private static final DotName CONTEXT = DotName.createSimple("io.smallrye.graphql.api.Context");
 }

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

@@ -8,22 +8,28 @@
 import java.util.Optional;
 
 import org.jboss.jandex.ClassInfo;
+import org.jboss.jandex.DotName;
 import org.jboss.jandex.FieldInfo;
 import org.jboss.jandex.MethodInfo;
+import org.jboss.jandex.MethodParameterInfo;
 import org.jboss.logging.Logger;
 
 import io.smallrye.graphql.schema.Annotations;
 import io.smallrye.graphql.schema.Classes;
 import io.smallrye.graphql.schema.ScanningContext;
+import io.smallrye.graphql.schema.SchemaBuilderException;
 import io.smallrye.graphql.schema.creator.FieldCreator;
+import io.smallrye.graphql.schema.creator.OperationCreator;
 import io.smallrye.graphql.schema.helper.DescriptionHelper;
 import io.smallrye.graphql.schema.helper.Direction;
 import io.smallrye.graphql.schema.helper.Directives;
 import io.smallrye.graphql.schema.helper.MethodHelper;
+import io.smallrye.graphql.schema.helper.TargetOperationHelper;
 import io.smallrye.graphql.schema.helper.TypeNameHelper;
 import io.smallrye.graphql.schema.model.DirectiveInstance;
 import io.smallrye.graphql.schema.model.Field;
 import io.smallrye.graphql.schema.model.InputType;
+import io.smallrye.graphql.schema.model.Operation;
 import io.smallrye.graphql.schema.model.Reference;
 import io.smallrye.graphql.schema.model.ReferenceType;
 
@@ -38,10 +44,12 @@
 public class InputTypeCreator implements Creator<InputType> {
     private static final Logger LOG = Logger.getLogger(InputTypeCreator.class.getName());
     private final FieldCreator fieldCreator;
+    private final OperationCreator operationCreator;
     private Directives directives;
 
-    public InputTypeCreator(FieldCreator fieldCreator) {
+    public InputTypeCreator(FieldCreator fieldCreator, OperationCreator operationCreator) {
         this.fieldCreator = fieldCreator;
+        this.operationCreator = operationCreator;
     }
 
     @Override
@@ -186,6 +194,37 @@ private void addFields(InputType inputType, ClassInfo classInfo, Reference refer
             }
         }
 
+        addTargetFields(inputType, classInfo);
+    }
+
+    private void addTargetFields(InputType inputType, ClassInfo classInfo) {
+        TargetOperationHelper targetOperationHelper = new TargetOperationHelper();
+        Map<DotName, List<MethodParameterInfo>> targetFields = targetOperationHelper.getTargetAnnotations();
+        if (!targetFields.containsKey(classInfo.name())) {
+            return;
+        }
+
+        List<MethodParameterInfo> methodParameterInfos = targetFields.get(classInfo.name());
+        for (MethodParameterInfo methodParameterInfo : methodParameterInfos) {
+            MethodInfo methodInfo = methodParameterInfo.method();
+            Operation targetOperation = operationCreator.createTargetOperation(methodInfo, inputType);
+            validateTargetFieldName(inputType, targetOperation);
+            inputType.addTargetField(targetOperation);
+        }
+    }
+
+    private void validateTargetFieldName(InputType inputType, Operation targetOperation) {
+        if (inputType.hasField(targetOperation.getName())) {
+            throw new SchemaBuilderException(String.format("Input type '%s' already contains field named '%s'" +
+                    " so target input field, with the same name, cannot be applied. You can resolve this conflict using @Name on the target method.",
+                    inputType.getName(),
+                    targetOperation.getName()));
+        }
+        if (inputType.hasTargetField(targetOperation.getName())) {
+            throw new SchemaBuilderException(String.format("Input type '%s' already contains target input field named '%s'",
+                    inputType.getName(),
+                    targetOperation.getName()));
+        }
     }
 
     private static final String JAVA_DOT = "java.";

common/schema-builder/src/main/java/io/smallrye/graphql/schema/helper/TargetOperationHelper.java

@@ -0,0 +1,55 @@
+package io.smallrye.graphql.schema.helper;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.jboss.jandex.AnnotationInstance;
+import org.jboss.jandex.AnnotationTarget;
+import org.jboss.jandex.DotName;
+import org.jboss.jandex.MethodParameterInfo;
+import org.jboss.jandex.Type;
+import org.jboss.logging.Logger;
+
+import io.smallrye.graphql.schema.Annotations;
+import io.smallrye.graphql.schema.ScanningContext;
+
+/**
+ * Finds all @Target input fields.
+ */
+public class TargetOperationHelper {
+    private final Logger LOG = Logger.getLogger(TargetOperationHelper.class.getName());
+
+    private final Map<DotName, List<MethodParameterInfo>> targetAnnotations = scanAllTargetAnnotations();
+
+    public Map<DotName, List<MethodParameterInfo>> getTargetAnnotations() {
+        return targetAnnotations;
+    }
+
+    private Map<DotName, List<MethodParameterInfo>> scanAllTargetAnnotations() {
+        Map<DotName, List<MethodParameterInfo>> targetFields = new HashMap<>();
+        Collection<AnnotationInstance> targetAnnotations = ScanningContext.getIndex().getAnnotations(Annotations.TARGET);
+        for (AnnotationInstance ai : targetAnnotations) {
+            AnnotationTarget target = ai.target();
+            if (target.kind().equals(AnnotationTarget.Kind.METHOD_PARAMETER)) {
+                MethodParameterInfo methodParameter = target.asMethodParameter();
+                Type targetType = methodParameter.method().parameterType(methodParameter.position());
+                DotName name = getName(targetType);
+                targetFields.computeIfAbsent(name, k -> new ArrayList<>()).add(methodParameter);
+            } else {
+                LOG.warn("Ignoring " + ai.target() + " on kind " + ai.target().kind() + ". Only expecting @"
+                        + Annotations.TARGET.local() + " on Method parameters");
+            }
+        }
+        return targetFields;
+    }
+
+    private DotName getName(Type targetType) {
+        if (targetType.kind().equals(Type.Kind.PARAMETERIZED_TYPE)) {
+            return targetType.asParameterizedType().name();
+        }
+        return targetType.name();
+    }
+}

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

@@ -179,6 +179,24 @@ public void testSchemaWithBatchSourceFieldNameDuplicates() {
         }
     }
 
+    @Test
+    public void testSchemaWithTargetInputFieldNameDuplicates() {
+        try {
+            Indexer indexer = new Indexer();
+            indexDirectory(indexer, "io/smallrye/graphql/index/duplicates/target");
+            indexDirectory(indexer, "io/smallrye/graphql/index/duplicates/target/targetfield");
+            IndexView index = indexer.complete();
+            SchemaBuilder.build(index);
+            Assertions.fail(
+                    "Schema should not build when there are both input field and target input field with the same defined name");
+        } catch (SchemaBuilderException e) {
+            // ok
+            assertEquals("Input type 'SomeInputInput' already contains field named 'password'" +
+                    " so target input field, with the same name, cannot be applied. You can resolve this conflict using @Name on the target method.",
+                    e.getMessage());
+        }
+    }
+
     @Test
     public void testSchemaWithInheritFieldBySubtype() {
         Indexer indexer = new Indexer();

common/schema-model/src/main/java/io/smallrye/graphql/schema/model/InputType.java

@@ -20,6 +20,8 @@ public final class InputType extends Reference {
 
     private Map<String, Field> fields = new LinkedHashMap<>();
 
+    private Map<String, Operation> targetFields = new LinkedHashMap<>();
+
     /**
      * All fields which are required by the creator method (e.g. {@code @JsonbCreator}).
      */
@@ -61,6 +63,26 @@ public boolean hasField(String fieldName) {
         return this.fields.containsKey(fieldName);
     }
 
+    public Map<String, Operation> getTargetFields() {
+        return targetFields;
+    }
+
+    public void setTargetFields(Map<String, Operation> targetFields) {
+        this.targetFields = targetFields;
+    }
+
+    public void addTargetField(Operation targetField) {
+        this.targetFields.put(targetField.getName(), targetField);
+    }
+
+    public boolean hasTargetFields() {
+        return !this.targetFields.isEmpty();
+    }
+
+    public boolean hasTargetField(String fieldName) {
+        return this.targetFields.containsKey(fieldName);
+    }
+
     public List<Field> getCreatorParameters() {
         return creatorParameters;
     }
@@ -75,8 +97,8 @@ public void addCreatorParameter(Field creatorParameter) {
 
     @Override
     public String toString() {
-        return "InputType{" + "description=" + description + ", fields=" + fields + ", creatorParameters=" + creatorParameters
-                + '}';
+        return "InputType{" + "description=" + description + ", fields=" + fields + ", targetFields="
+                + targetFields + ", creatorParameters=" + creatorParameters + '}';
     }
 
 }