Fix generated CriteriaExpression not working with UUIDs (#42)

* Fix generated CriteriaExpression not working with UUIDs

* Add a test for where expressions not working with UUIDs

* Add a test for checking IN values for UUIDs

* Also check for IN when handling UUIDs

* Remove unnecessary type constraints

* [tests] Add a test for testing UUIDs in a where clause with NE as comparison operator.

Author: czyba

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

@@ -22,6 +22,8 @@
 import java.util.Date;
 import java.util.EnumSet;
 import java.util.Set;
+import java.util.UUID;
+
 
 import javax.persistence.criteria.CriteriaBuilder;
 import javax.persistence.criteria.Expression;
@@ -262,6 +264,29 @@ protected Predicate getDatePredicate(Path<? extends Date> root, PredicateFilter
         return null;
     }
 
+    private Predicate getUuidPredicate(Path<UUID> field, PredicateFilter filter) {
+        if (filter.getValue() == null) {
+            return null;
+        }
+        final Predicate arrayPredicate = mayBeArrayValuePredicate(field, filter);
+        if (arrayPredicate != null) {
+            return arrayPredicate;
+        }
+        final UUID compareValue = (UUID) filter.getValue();
+
+        if (filter.getCriterias().contains(PredicateFilter.Criteria.EQ)) {
+            return cb.equal(field, compareValue);
+        }
+        if (filter.getCriterias().contains(PredicateFilter.Criteria.IN)) {
+            final CriteriaBuilder.In<Object> in = cb.in(field);
+            return in.value(compareValue);
+        }
+        if (filter.getCriterias().contains(PredicateFilter.Criteria.NE)) {
+            return cb.notEqual(field, compareValue);
+        }
+        return null;
+    }
+
     @SuppressWarnings("unchecked")
     private Predicate getTypedPredicate(From<?,?> from, Path<?> field, PredicateFilter filter) {
         Class<?> type = field.getJavaType();
@@ -303,6 +328,9 @@ else if (type.equals(java.util.Date.class)) {
         else if (type.equals(Boolean.class)) {
             return getBooleanPredicate(field, predicateFilter);
         }
+        else if (type.equals(UUID.class)) {
+            return getUuidPredicate((Path<UUID>) field, predicateFilter);
+        }
         else if(Collection.class.isAssignableFrom(type)) {
             if(field.getModel() == null)
                 return from.join(filter.getField()).in(value);
@@ -324,4 +352,4 @@ else if(Collection.class.isAssignableFrom(type)) {
     public Predicate getPredicate(From<?,?> from, Path<?> field, PredicateFilter filter) {
         return getTypedPredicate(from, field, filter);
     }
-}
+}

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

@@ -19,6 +19,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 import java.util.HashMap;
+import java.util.UUID;
 
 import javax.persistence.EntityManager;
 
@@ -136,7 +137,61 @@ public void queryWithParameterNoResult() {
         //then:
         assertThat(result.toString()).isEqualTo(expected);
     }
-    
+
+    @SuppressWarnings( { "rawtypes", "unchecked", "serial" } )
+    @Test
+    public void queryForThingByIdViaWhere() {
+        //given:
+
+        String query = "query { Things(where: {id: {EQ: \"2d1ebc5b-7d27-4197-9cf0-e84451c5bbb1\"}}) { select { id }}}";
+        String expected = "{Things={select=[{id=2d1ebc5b-7d27-4197-9cf0-e84451c5bbb1}]}}";
+
+        //when:
+        Object result = executor.execute(query).getData();
+
+        //then:
+        assertThat(result.toString()).isEqualTo(expected);
+    }
+
+    @SuppressWarnings( { "rawtypes", "unchecked", "serial" } )
+    @Test
+    public void queryForThingByIdViaWhereIN() {
+        //given:
+
+        String query = "query { Things(where: {id: {IN: [\"2d1ebc5b-7d27-4197-9cf0-e84451c5bbb1\", \"2d1ebc5b-7d27-4197-9cf0-e84451c5bbb1\" ]}}) { select { id }}}";
+        String expected = "{Things={select=[{id=2d1ebc5b-7d27-4197-9cf0-e84451c5bbb1}]}}";
+
+        //when:
+        Object result = executor.execute(query).getData();
+
+        //then:
+        assertThat(result.toString()).isEqualTo(expected);
+    }
+
+    @SuppressWarnings( { "rawtypes", "unchecked", "serial" } )
+    @Test
+    public void queryForThingByIdViaWhereNE() {
+        //given:
+
+        String query = "query { Things(where: {id: {NE: \"2d1ebc5b-7d27-4197-9cf0-e84451c5bbb2\"}}) { select { id }}}";
+        String expected = "{Things={select=[{id=2d1ebc5b-7d27-4197-9cf0-e84451c5bbb1}]}}";
+
+        //when:
+        Object result = executor.execute(query).getData();
+
+        //then:
+        assertThat(result.toString()).isEqualTo(expected);
+
+        query = "query { Things(where: {id: {NE: \"2d1ebc5b-7d27-4197-9cf0-e84451c5bbb1\"}}) { select { id }}}";
+        expected = "{Things={select=[]}}";
+
+        //when:
+        result = executor.execute(query).getData();
+
+        //then:
+        assertThat(result.toString()).isEqualTo(expected);
+    }
+
     @Test
     public void queryWithAlias() {
         //given: