Extended empty array test method

Author: chernser

jdbc-v2/src/main/java/com/clickhouse/jdbc/types/ArrayResultSet.java

@@ -458,7 +458,7 @@ public boolean isFirst() throws SQLException {
 
     @Override
     public boolean isLast() throws SQLException {
-        return pos == length - 1;
+        return length > 0 && pos == length - 1;
     }
 
     @Override

jdbc-v2/src/test/java/com/clickhouse/jdbc/types/ArrayResultSetTest.java

@@ -283,7 +283,22 @@ void testStringValues() throws SQLException {
     @Test
     void testEmptyArray() throws SQLException {
         ArrayResultSet rs = new ArrayResultSet(new Object[0], ClickHouseColumn.parse("v Array(Int32)").get(0));
+
+        Assert.assertTrue(rs.isBeforeFirst());
+        Assert.assertFalse(rs.isAfterLast());
+        Assert.assertFalse(rs.isLast());
+        Assert.assertFalse(rs.isFirst());
+
         assertFalse(rs.next());
+
+        Assert.assertTrue(rs.isBeforeFirst());
+        Assert.assertFalse(rs.isAfterLast());
+        Assert.assertFalse(rs.isLast());
+        Assert.assertFalse(rs.isFirst());
+
+        Assert.assertThrows(SQLException.class, () -> rs.getString("col1"));
+        Assert.assertThrows(SQLException.class, () -> rs.getObject("col1"));
+        Assert.assertThrows(SQLException.class, () -> rs.getInt("col1"));
     }
 
     @Test