feat: add count method to QueryAQLConverter

Implemented a count method that constructs an AQL query
to return the length of results based on a given SelectQuery.

Signed-off-by: Maximillian Arruda <[email protected]>

Author: dearrudam

jnosql-arangodb/src/main/java/org/eclipse/jnosql/databases/arangodb/communication/QueryAQLConverter.java

@@ -77,6 +77,23 @@ public static AQLQueryResult select(SelectQuery query) throws NullPointerExcepti
 
     }
 
+    public static AQLQueryResult count(SelectQuery query) throws NullPointerException {
+
+        AQLQueryResult q = convert(query.name(),
+                query.condition().orElse(null),
+                Collections.emptyList(),
+                0L,
+                0L,
+                RETURN, false);
+
+        StringBuilder aql = new StringBuilder();
+
+        aql.append("RETURN LENGTH(")
+                .append(q.query())
+                .append(")");
+        return new AQLQueryResult(aql.toString(), q.values());
+    }
+
 
     private static AQLQueryResult convert(String documentCollection,
                                           CriteriaCondition documentCondition,

jnosql-arangodb/src/test/java/org/eclipse/jnosql/databases/arangodb/communication/QueryAQLConverterTest.java

@@ -155,4 +155,18 @@ public void shouldNegate() {
 
     }
 
+    @Test
+    public void shouldRunEqualsCountQuery() {
+        SelectQuery query = select().from("collection")
+                .where("name").eq("value").build();
+
+        AQLQueryResult convert = QueryAQLConverter.count(query);
+        String aql = convert.query();
+        Map<String, Object> values = convert.values();
+        assertEquals("value", values.get("name"));
+        assertEquals("RETURN LENGTH(FOR c IN collection FILTER  c.name == @name RETURN c)", aql);
+
+    }
+
+
 }