Dispatch empty query to server

This update ensures that empty query gets dispatched to server and expects it to handle it accordingly.

Please note that empty query string will no longer produce `IllegalArgumentException`. Instead, its handling will be defined by server that might produce `ClientException`.

Author: injectives

driver/src/main/java/org/neo4j/driver/Query.java

@@ -25,10 +25,10 @@
 import org.neo4j.driver.util.Immutable;
 
 import static java.lang.String.format;
-import static org.neo4j.driver.internal.util.Iterables.newHashMapWithSize;
-import static org.neo4j.driver.internal.util.Preconditions.checkArgument;
 import static org.neo4j.driver.Values.ofValue;
 import static org.neo4j.driver.Values.value;
+import static org.neo4j.driver.internal.util.Iterables.newHashMapWithSize;
+import static org.neo4j.driver.internal.util.Preconditions.checkArgument;
 
 /**
  * The components of a Cypher query, containing the query text and parameter map.
@@ -201,7 +201,6 @@ public String toString()
     private static String validateQueryText(String query )
     {
         checkArgument( query != null, "Cypher query text should not be null" );
-        checkArgument( !query.isEmpty(), "Cypher query text should not be an empty string" );
         return query;
     }
 }

driver/src/test/java/org/neo4j/driver/QueryTest.java

@@ -25,6 +25,7 @@
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.junit.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.neo4j.driver.Values.parameters;
 
@@ -121,8 +122,12 @@ void shouldProhibitNullQuery()
     }
 
     @Test
-    void shouldProhibitEmptyQuery()
+    void shouldAcceptEmptyQuery()
     {
-        assertThrows( IllegalArgumentException.class, () -> new Query( "" ) );
+        // when
+        Query query = new Query( "" );
+
+        // then
+        assertNotNull( query );
     }
 }

driver/src/test/java/org/neo4j/driver/integration/QueryIT.java

@@ -18,13 +18,9 @@
  */
 package org.neo4j.driver.integration;
 
-import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
-import org.junit.jupiter.api.function.Executable;
 
-import java.io.PrintWriter;
-import java.io.StringWriter;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
@@ -34,13 +30,13 @@
 import org.neo4j.driver.Result;
 import org.neo4j.driver.Value;
 import org.neo4j.driver.Values;
+import org.neo4j.driver.exceptions.ClientException;
 import org.neo4j.driver.util.ParallelizableIT;
 import org.neo4j.driver.util.SessionExtension;
 
 import static java.util.Arrays.asList;
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.neo4j.driver.Values.parameters;
 import static org.neo4j.driver.util.TestUtil.assertNoCircularReferences;
@@ -186,7 +182,7 @@ void shouldRunSimpleQuery()
     void shouldFailForIllegalQueries()
     {
         assertThrows( IllegalArgumentException.class, () -> session.run( (String) null ) );
-        assertThrows( IllegalArgumentException.class, () -> session.run( "" ) );
+        assertThrows( ClientException.class, () -> session.run( "" ) );
     }
 
     @Test