feat: add LOCATE predicate for JPA entity attributes annotated with @convert (#115)

* feat: add LOCATE predicate for attributes annotated with @convert

* fix: polish test data

* fix: clean up old code.

Author: igdianov

.gitignore

@@ -21,3 +21,6 @@ target/
 .project
 .springBeans
 .classpath
+
+.externalToolBuilders
+

graphql-jpa-query-schema/pom.xml

@@ -60,6 +60,12 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <scope>test</scope>
+        </dependency>
+        
     </dependencies>
 
 </project>

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

@@ -66,10 +66,6 @@ public Object get(DataFetchingEnvironment environment) {
 
             //EntityGraph<?> entityGraph = buildEntityGraph(new Field("select", new SelectionSet(Arrays.asList(field))));
 
-            // Let's clear session persistent context to avoid getting stale objects cached in the same session 
-            // between requests with different search criteria. This looks like a Hibernate bug... 
-            entityManager.clear();
-            
             return getQuery(environment, field, true)
                 //.setHint("javax.persistence.fetchgraph", entityGraph) // TODO: fix runtime exception
                 .getResultList();

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

@@ -33,6 +33,7 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import javax.persistence.Convert;
 import javax.persistence.EntityManager;
 import javax.persistence.Transient;
 import javax.persistence.metamodel.Attribute;
@@ -43,9 +44,6 @@
 import javax.persistence.metamodel.SingularAttribute;
 import javax.persistence.metamodel.Type;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import com.introproventures.graphql.jpa.query.annotation.GraphQLDescription;
 import com.introproventures.graphql.jpa.query.annotation.GraphQLIgnore;
 import com.introproventures.graphql.jpa.query.annotation.GraphQLIgnoreFilter;
@@ -55,7 +53,6 @@
 import com.introproventures.graphql.jpa.query.schema.NamingStrategy;
 import com.introproventures.graphql.jpa.query.schema.impl.IntrospectionUtils.CachedIntrospectionResult.CachedPropertyDescriptor;
 import com.introproventures.graphql.jpa.query.schema.impl.PredicateFilter.Criteria;
-
 import graphql.Assert;
 import graphql.Scalars;
 import graphql.schema.Coercing;
@@ -73,6 +70,8 @@
 import graphql.schema.GraphQLType;
 import graphql.schema.GraphQLTypeReference;
 import graphql.schema.PropertyDataFetcher;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * JPA specific schema builder implementation of {code #GraphQLSchemaBuilder} interface
@@ -437,6 +436,16 @@ private GraphQLInputType getWhereAttributeType(Attribute<?,?> attribute) {
                         .type(getAttributeInputType(attribute))
                         .build()
                     );
+                } 
+                else if (attribute.getJavaMember().getClass().isAssignableFrom(Field.class) 
+                        && Field.class.cast(attribute.getJavaMember())
+                                      .isAnnotationPresent(Convert.class)) 
+                {
+                    builder.field(GraphQLInputObjectField.newInputObjectField()
+                                                         .name(Criteria.LOCATE.name())
+                                                         .description("Locate search criteria")
+                                                         .type(getAttributeInputType(attribute))
+                                                         .build());
                 }
             }
 

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

@@ -414,6 +414,9 @@ else if(Collection.class.isAssignableFrom(type)) {
         } else if(type.isEnum()) {
         	return getEnumPredicate((Path<Enum<?>>) field, predicateFilter);
         }
+        else if (filter.getCriterias().contains(PredicateFilter.Criteria.LOCATE)) {
+            return cb.gt(cb.locate(from.<String>get(filter.getField()), value.toString()), 0); 
+        }
 
         throw new IllegalArgumentException("Unsupported field type " + type + " for field " + predicateFilter.getField());
     }

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

@@ -103,7 +103,12 @@ public enum Criteria {
         /**
          * Not Between condition
          */
-        NOT_BETWEEN;
+        NOT_BETWEEN,
+
+        /**
+         * JPA's LOCATE predicate for attributes annotated with @Convert
+         */
+        LOCATE;
 
         private static Set<String> names = EnumSet.allOf(Criteria.class)
                                                   .stream()