ResultSetEnumerator#each to return Enumerator when block not given

CHANGELOG.md

@@ -3,6 +3,7 @@
 * Added MariaDB connector
 * Added SQLite connector
 * Deprecated the use of `JDBCHelper::SQL`
+* `ResultSetEnumerator#each` returns an enumerator when block is not given
 
 ### 0.7.7 / 2013/01/0?
 * `PreparedStatment`s and `TableWrapper`s now inherit the fetch size of the connection

lib/jdbc-helper/connection.rb

@@ -315,10 +315,10 @@ def query(qstr, &blk)
   # @yield [JDBCHelper::Connection::Row] Yields each record if block is given
   # @return [JDBCHelper::Connection::ResultSetEnumerator] Returns an enumerator if block is not given
   def enumerate(qstr, &blk)
-    check_closed
-
     return query(qstr, &blk) if block_given?
 
+    check_closed
+
     stmt = @spool.take
     begin
       rset = stmt.execute_query(qstr)

lib/jdbc-helper/connection/result_set_enumerator.rb

@@ -11,6 +11,7 @@ class ResultSetEnumerator
   include Enumerable
 
   def each
+    return enum_for(:each) unless block_given?
     return if closed?
 
     count = -1

test/test_connection.rb

@@ -210,6 +210,35 @@ def test_query_enumerate
       assert_equal 2, a.length
       check_one_two a.first
       assert enum.closed? == true
+
+      # Enumerator chain
+      cnt = 0
+      enum = conn.enumerate(get_one_two)
+      assert_equal false, enum.closed?
+      enum.each.each.each.each_slice(1) do |slice|
+        assert_equal Array, slice.class
+        assert_equal 1,     slice.length
+        cnt += 1
+        assert_equal false, enum.closed?
+      end
+      assert_equal true, enum.closed?
+      assert_equal 2, cnt
+
+      cnt = 0
+      enum = conn.enumerate(get_one_two)
+      assert_equal false, enum.closed?
+      enum.each.each.each.with_index.each_slice(2).each do |slice|
+        assert_equal Array,   slice.class
+        assert_equal 2,       slice.length
+        assert_equal Array,   slice[0].class
+        assert_equal 2,       slice[0].length
+        assert_equal cnt,     slice[0][1]
+        assert_equal cnt + 1, slice[1][1]
+        cnt += 2
+        assert_equal false, enum.closed?
+      end
+      assert_equal true, enum.closed?
+      assert_equal 2, cnt
     end
   end