feat: support enum variable bindings in queries

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

@@ -540,12 +540,27 @@ protected Object convertValue(DataFetchingEnvironment environment, Argument argu
                 return ((StringValue) value).getValue();
             }
         }
-        else if (value instanceof VariableReference)
-            // Get resolved variable in environment arguments
-            return environment.getArguments().get(argument.getName());
-        else if (value instanceof ArrayValue) {
+        else if (value instanceof VariableReference) {
+            Class javaType = getJavaType(environment, argument);
+            Object argumentValue = environment.getArguments().get(argument.getName());
+            if(javaType.isEnum()) {
+                if(argumentValue instanceof Collection) {
+                    List<Enum> values = new ArrayList<>();
+
+                    Collection.class.cast(argumentValue)
+                                    .forEach(it -> values.add(Enum.valueOf(javaType, it.toString()))); 
+                    return values;
+                } else {
+                    return Enum.valueOf(javaType, argumentValue.toString());
+                }
+            } 
+            else {    
+                // Get resolved variable in environment arguments
+                return argumentValue;
+            }
+        } else if (value instanceof ArrayValue) {
             Object convertedValue =  environment.getArgument(argument.getName());
-            if (convertedValue != null) {
+            if (convertedValue != null && !getJavaType(environment, argument).isEnum()) {
                 // unwrap [[EnumValue{name='value'}]]
                 if(convertedValue instanceof Collection
                     && ((Collection) convertedValue).stream().allMatch(it->it instanceof Collection)) {

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

@@ -0,0 +1,208 @@
+/*
+ * Copyright 2017 IntroPro Ventures Inc. and/or its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.introproventures.graphql.jpa.query.schema;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.persistence.EntityManager;
+
+import com.introproventures.graphql.jpa.query.schema.impl.GraphQLJpaExecutor;
+import com.introproventures.graphql.jpa.query.schema.impl.GraphQLJpaSchemaBuilder;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.context.annotation.Bean;
+import org.springframework.test.context.TestPropertySource;
+import org.springframework.test.context.junit4.SpringRunner;
+
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment=WebEnvironment.NONE)
+@TestPropertySource({"classpath:hibernate.properties"})
+public class GraphQLEnumVariableBindingsTests {
+
+    @SpringBootApplication
+    static class Application {
+        @Bean
+        public GraphQLExecutor graphQLExecutor(final GraphQLSchemaBuilder graphQLSchemaBuilder) {
+            return new GraphQLJpaExecutor(graphQLSchemaBuilder.build());
+        }
+
+        @Bean
+        public GraphQLSchemaBuilder graphQLSchemaBuilder(final EntityManager entityManager) {
+
+            return new GraphQLJpaSchemaBuilder(entityManager)
+                .name("GraphQLBooks")
+                .description("Books JPA test schema");
+        }
+
+    }
+
+    @Autowired
+    private GraphQLExecutor executor;
+
+
+    @Test
+    public void queryEnumSimpleVariableBinding() {
+        //given
+        String query = "query($genre: Genre) {" + 
+                "    Books(where: {" + 
+                "    genre: {EQ: $genre}" + 
+                "  }) {" + 
+                "    select {" + 
+                "      id" + 
+                "      title" + 
+                "      genre" + 
+                "    }" + 
+                "  }" + 
+                "}";
+
+        Map<String, Object> variables = new HashMap<String, Object>() {{
+            put("genre", "NOVEL");
+        }};
+
+
+        String expected = "{Books={select=["
+                + "{id=2, title=War and Peace, genre=NOVEL}, "
+                + "{id=3, title=Anna Karenina, genre=NOVEL}"
+                + "]}}";
+
+        //when
+        Object result = executor.execute(query, variables).getData();
+
+        // then
+        assertThat(result.toString()).isEqualTo(expected);
+    }     
+
+    @Test
+    public void queryEnumSimpleArrayVariableBinding() {
+        //given
+        String query = "query($genre: Genre) {" + 
+                "    Books(where: {" + 
+                "    genre: {IN: [$genre]}" + 
+                "  }) {" + 
+                "    select {" + 
+                "      id" + 
+                "      title" + 
+                "      genre" + 
+                "    }" + 
+                "  }" + 
+                "}";
+
+        Map<String, Object> variables = new HashMap<String, Object>() {{
+            put("genre", "NOVEL");
+        }};
+
+
+        String expected = "{Books={select=["
+                + "{id=2, title=War and Peace, genre=NOVEL}, "
+                + "{id=3, title=Anna Karenina, genre=NOVEL}"
+                + "]}}";
+
+        //when
+        Object result = executor.execute(query, variables).getData();
+
+        // then
+        assertThat(result.toString()).isEqualTo(expected);
+    }     
+
+    @Test
+    public void queryEnumArrayVariableBindingInNestedRelation() {
+        //given
+        String query = "query($genres: [Genre!]) {" + 
+                "    Authors(where: {" + 
+                "    books: {" + 
+                "        genre: {IN: $genres}" + 
+                "    }" + 
+                "  }) {" + 
+                "    select {" + 
+                "      id" + 
+                "      name" + 
+                "      books {" + 
+                "        id" + 
+                "        title" + 
+                "        genre" + 
+                "      }" + 
+                "    }" + 
+                "  }" + 
+                "}";
+
+        Map<String, Object> variables = new HashMap<String, Object>() {{
+            put("genres", Arrays.asList("NOVEL"));
+        }};
+
+
+        String expected = "{Authors={select=[{"
+                + "id=1, name=Leo Tolstoy, books=["
+                +   "{id=2, title=War and Peace, genre=NOVEL}, "
+                +   "{id=3, title=Anna Karenina, genre=NOVEL}"
+                + "]}"
+                + "]}}";
+
+        //when
+        Object result = executor.execute(query, variables).getData();
+
+        // then
+        assertThat(result.toString()).isEqualTo(expected);
+    }        
+
+    @Test
+    public void queryEnumArrayVariableBindingInEmbeddedRelation() {
+        //given
+        String query = "query($genres: [Genre!]) {" + 
+                "    Authors {" + 
+                "    select {" + 
+                "      id" + 
+                "      name" + 
+                "      books(where:  {" + 
+                "        genre: {IN: $genres}" + 
+                "    }) {" + 
+                "        id" + 
+                "        title" + 
+                "        genre" + 
+                "      }" + 
+                "    }" + 
+                "  }  " + 
+                "}";
+
+        Map<String, Object> variables = new HashMap<String, Object>() {{
+            put("genres", Arrays.asList("NOVEL"));
+        }};
+
+
+        String expected = "{Authors={select=["
+                +   "{id=1, name=Leo Tolstoy, books=["
+                +       "{id=2, title=War and Peace, genre=NOVEL}, "
+                +       "{id=3, title=Anna Karenina, genre=NOVEL}"
+                +   "]}, "
+                +   "{id=4, name=Anton Chekhov, books=[]}"
+                + "]}}";
+
+        //when
+        Object result = executor.execute(query, variables).getData();
+
+        // then
+        assertThat(result.toString()).isEqualTo(expected);
+    }
+}