Add optional support for GraphQLIDType (i.e. ID) for entity identifier attributes (#401)

Author: igdianov

schema/src/main/java/com/introproventures/graphql/jpa/query/schema/GraphQLSchemaBuilder.java

@@ -67,6 +67,14 @@ public interface GraphQLSchemaBuilder {
      */
     GraphQLSchemaBuilder scalar(Class<?> javaType, GraphQLScalarType scalarType);
 
+    /**
+     * Use GraphQLIDType attribute for entity identifier attributes. Defaults to false.
+     *
+     * @param useGraphQLIDType fl
+     * @return this builder instance
+     */
+    GraphQLSchemaBuilder graphQLIDType(boolean useGraphQLIDType);
+
     /**
      * Builds {code #GraphQLSchema} instance
      *

schema/src/main/java/com/introproventures/graphql/jpa/query/schema/impl/GraphQLJpaQueryFactory.java

@@ -1501,8 +1501,11 @@ protected Object convertValue(DataFetchingEnvironment environment, Argument argu
         } else if (value instanceof StringValue) {
             Object convertedValue = environment.getArgument(argument.getName());
             if (convertedValue != null) {
+                Class javaType = getJavaType(environment, argument);
                 // Return real typed resolved value even if the Value is a StringValue
-                return convertedValue;
+                return javaType.isInstance(convertedValue)
+                    ? convertedValue
+                    : JavaScalars.of(javaType).getCoercing().parseValue(convertedValue);
             } else {
                 // Return provided StringValue
                 return ((StringValue) value).getValue();
@@ -1522,7 +1525,9 @@ protected Object convertValue(DataFetchingEnvironment environment, Argument argu
                 }
             } else {
                 // Get resolved variable in environment arguments
-                return argumentValue;
+                return javaType.isInstance(argumentValue)
+                    ? argumentValue
+                    : JavaScalars.of(javaType).getCoercing().parseValue(argumentValue);
             }
         } else if (value instanceof ArrayValue) {
             Collection arrayValue = environment.getArgument(argument.getName());

schema/src/main/java/com/introproventures/graphql/jpa/query/schema/impl/GraphQLJpaSchemaBuilder.java

@@ -131,6 +131,7 @@ public class GraphQLJpaSchemaBuilder implements GraphQLSchemaBuilder {
     private int defaultPageLimitSize = 100;
     private boolean enableDefaultMaxResults = true;
     private boolean enableResultStream = false;
+    private boolean graphQLIDType = false;
 
     private RestrictedKeysProvider restrictedKeysProvider = entityDescriptor -> Optional.of(Collections.emptyList());
     private Map<Class<?>, GraphQLScalarType> scalars = new LinkedHashMap<>();
@@ -1246,7 +1247,9 @@ private GraphQLOutputType getAttributeOutputType(Attribute<?, ?> attribute) {
     @SuppressWarnings("rawtypes")
     protected GraphQLType getAttributeType(Attribute<?, ?> attribute, boolean input, boolean searchByIdArgType) {
         if (isBasic(attribute)) {
-            return getGraphQLTypeFromJavaType(attribute.getJavaType());
+            return searchByIdArgType && isGraphQLIDType()
+                ? Scalars.GraphQLID
+                : getGraphQLTypeFromJavaType(attribute.getJavaType());
         } else if (isEmbeddable(attribute)) {
             EmbeddableType embeddableType = (EmbeddableType) ((SingularAttribute) attribute).getType();
             return getEmbeddableType(embeddableType, input, searchByIdArgType);
@@ -1667,4 +1670,15 @@ public GraphQLJpaSchemaBuilder enableResultStream(boolean enableResultStream) {
 
         return this;
     }
+
+    @Override
+    public GraphQLJpaSchemaBuilder graphQLIDType(boolean graphQLIDType) {
+        this.graphQLIDType = graphQLIDType;
+
+        return this;
+    }
+
+    public boolean isGraphQLIDType() {
+        return this.graphQLIDType;
+    }
 }