text: // Copyright (c) 2014, Suryandaru Triandana <syndtr@gmail.com>
  // All rights reserved.
  //
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  package iterator_test
  
  import (
  	. "github.com/onsi/ginkgo"
  	. "github.com/onsi/gomega"
  
  	"github.com/syndtr/goleveldb/leveldb/comparer"
  	. "github.com/syndtr/goleveldb/leveldb/iterator"
  	"github.com/syndtr/goleveldb/leveldb/testutil"
  )
  
  var _ = testutil.Defer(func() {
  	Describe("Merged iterator", func() {
  		Test := func(filled int, empty int) func() {
  			return func() {
  				It("Should iterates and seeks correctly", func(done Done) {
  					rnd := testutil.NewRand()
  
  					// Build key/value.
  					filledKV := make([]testutil.KeyValue, filled)
  					kv := testutil.KeyValue_Generate(nil, 100, 1, 1, 10, 4, 4)
  					kv.Iterate(func(i int, key, value []byte) {
  						filledKV[rnd.Intn(filled)].Put(key, value)
  					})
  
  					// Create itearators.
  					iters := make([]Iterator, filled+empty)
  					for i := range iters {
  						if empty == 0 || (rnd.Int()%2 == 0 && filled > 0) {
  							filled--
  							Expect(filledKV[filled].Len()).ShouldNot(BeZero())
  							iters[i] = NewArrayIterator(filledKV[filled])
  						} else {
  							empty--
  							iters[i] = NewEmptyIterator(nil)
  						}
  					}
  
  					// Test the iterator.
  					t := testutil.IteratorTesting{
  						KeyValue: kv.Clone(),
  						Iter:     NewMergedIterator(iters, comparer.DefaultComparer, true),
  					}
  					testutil.DoIteratorTesting(&t)
  					done <- true
  				}, 15.0)
  			}
  		}
  
  		Describe("with three, all filled iterators", Test(3, 0))
  		Describe("with one filled, one empty iterators", Test(1, 1))
  		Describe("with one filled, two empty iterators", Test(1, 2))
  	})
  })
  