feat: add scalar builder method to graphql query schema builder (#318)

* fix: add scalar registration method to GraphQLJpaSchemaBuilder

* fix: add schema builder scalar test

Author: igdianov

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

@@ -15,6 +15,7 @@
  */
 package com.introproventures.graphql.jpa.query.schema;
 
+import graphql.schema.GraphQLScalarType;
 import graphql.schema.GraphQLSchema;
 
 /**
@@ -57,7 +58,17 @@ public interface GraphQLSchemaBuilder {
      * @return this builder instance
      */
     GraphQLSchemaBuilder namingStrategy(NamingStrategy instance);
-    
+
+
+    /**
+     * Register Java type scalar
+     *
+     * @param javaType class
+     * @param scalarType GraphQL scalar instance
+     * @return this builder instance
+     */
+    GraphQLSchemaBuilder scalar(Class<?> javaType, GraphQLScalarType scalarType);
+
     /**
      * Builds {code #GraphQLSchema} instance
      * 

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

@@ -16,6 +16,31 @@
 
 package com.introproventures.graphql.jpa.query.schema.impl;
 
+import java.beans.Introspector;
+import java.lang.reflect.AnnotatedElement;
+import java.lang.reflect.Field;
+import java.lang.reflect.Member;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import javax.persistence.Convert;
+import javax.persistence.EntityManager;
+import javax.persistence.metamodel.Attribute;
+import javax.persistence.metamodel.EmbeddableType;
+import javax.persistence.metamodel.EntityType;
+import javax.persistence.metamodel.ManagedType;
+import javax.persistence.metamodel.PluralAttribute;
+import javax.persistence.metamodel.SingularAttribute;
+import javax.persistence.metamodel.Type;
 import com.introproventures.graphql.jpa.query.annotation.GraphQLIgnore;
 import com.introproventures.graphql.jpa.query.annotation.GraphQLIgnoreFilter;
 import com.introproventures.graphql.jpa.query.annotation.GraphQLIgnoreOrder;
@@ -41,6 +66,7 @@
 import graphql.schema.GraphQLList;
 import graphql.schema.GraphQLObjectType;
 import graphql.schema.GraphQLOutputType;
+import graphql.schema.GraphQLScalarType;
 import graphql.schema.GraphQLSchema;
 import graphql.schema.GraphQLType;
 import graphql.schema.GraphQLTypeReference;
@@ -49,31 +75,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import javax.persistence.Convert;
-import javax.persistence.EntityManager;
-import javax.persistence.metamodel.Attribute;
-import javax.persistence.metamodel.EmbeddableType;
-import javax.persistence.metamodel.EntityType;
-import javax.persistence.metamodel.ManagedType;
-import javax.persistence.metamodel.PluralAttribute;
-import javax.persistence.metamodel.SingularAttribute;
-import javax.persistence.metamodel.Type;
-import java.beans.Introspector;
-import java.lang.reflect.AnnotatedElement;
-import java.lang.reflect.Field;
-import java.lang.reflect.Member;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.function.Supplier;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
 import static graphql.Scalars.GraphQLBoolean;
 import static graphql.schema.GraphQLArgument.newArgument;
 import static graphql.schema.GraphQLInputObjectField.newInputObjectField;
@@ -133,6 +134,7 @@ public class GraphQLJpaSchemaBuilder implements GraphQLSchemaBuilder {
     private boolean enableResultStream = false;
 
     private RestrictedKeysProvider restrictedKeysProvider = (entityDescriptor) -> Optional.of(Collections.emptyList());
+    private Map<Class<?>, GraphQLScalarType> scalars = new LinkedHashMap<>();
 
     private final Relay relay = new Relay();
 
@@ -151,6 +153,8 @@ public GraphQLJpaSchemaBuilder(EntityManager entityManager) {
      */
     @Override
     public GraphQLSchema build() {
+        scalars.forEach((javaType, scalarType) -> JavaScalars.register(javaType, scalarType));
+
         GraphQLSchema.Builder schema = GraphQLSchema.newSchema()
                                                     .query(getQueryType());
 
@@ -165,6 +169,12 @@ public GraphQLSchema build() {
         return schema.build();
     }
 
+    public GraphQLJpaSchemaBuilder scalar(Class<?> javaType, GraphQLScalarType scalarType) {
+        scalars.put(javaType, scalarType);
+
+        return this;
+    }
+
     private GraphQLObjectType getQueryType() {
         GraphQLObjectType.Builder queryType =
             GraphQLObjectType.newObject()

graphql-jpa-query-schema/src/test/java/com/introproventures/graphql/jpa/query/schema/StarwarsSchemaBuildTest.java

@@ -16,10 +16,15 @@
 
 package com.introproventures.graphql.jpa.query.schema;
 
-import static org.assertj.core.api.Assertions.assertThat;
-
+import java.util.Optional;
 import javax.persistence.EntityManager;
-
+import com.introproventures.graphql.jpa.query.AbstractSpringBootTestSupport;
+import com.introproventures.graphql.jpa.query.schema.impl.GraphQLJpaSchemaBuilder;
+import graphql.Scalars;
+import graphql.schema.GraphQLInputObjectType;
+import graphql.schema.GraphQLObjectType;
+import graphql.schema.GraphQLScalarType;
+import graphql.schema.GraphQLSchema;
 import org.junit.Before;
 import org.junit.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -28,13 +33,7 @@
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.context.annotation.Bean;
 
-import com.introproventures.graphql.jpa.query.AbstractSpringBootTestSupport;
-import com.introproventures.graphql.jpa.query.schema.impl.GraphQLJpaSchemaBuilder;
-
-import graphql.Scalars;
-import graphql.schema.GraphQLInputObjectType;
-import graphql.schema.GraphQLObjectType;
-import graphql.schema.GraphQLSchema;
+import static org.assertj.core.api.Assertions.assertThat;
 
 @SpringBootTest
 public class StarwarsSchemaBuildTest extends AbstractSpringBootTestSupport {
@@ -188,5 +187,25 @@ public void testBuildSchema(){
         //then
         assertThat(schema).isNotNull();
     }
+
+    @Test
+    public void scalar() {
+        // given
+        GraphQLScalarType scalarType = GraphQLScalarType.newScalar()
+                                                        .name("TestObject")
+                                                        .coercing(new JavaScalars.GraphQLObjectCoercing())
+                                                        .build();
+
+        // when
+        builder.scalar(Object.class, scalarType)
+               .build();
+
+        // then
+        Optional<GraphQLScalarType> result = JavaScalars.of(scalarType.getName());
+
+        assertThat(result).isNotEmpty()
+                          .get()
+                          .isEqualTo(scalarType);
+    }
 
 }