bugfix

packer.go

@@ -72,10 +72,11 @@ func (p *Packer) preferredSort(boxes boxSlice, items itemSlice) boxSlice {
 func (p *Packer) packToBox(b *Box, items []*Item) []*Item {
  var fitted bool
 
- unpacked := make([]*Item, 0, len(items))
+ cntItems := len(items)
+ unpacked := make([]*Item, 0, cntItems)
  pv := Pivot{}
 
- if b.items == nil && b.PutItem(items[0], pv) {
+ if b.items == nil && cntItems > 0 && b.PutItem(items[0], pv) {
  items = items[1:]
  }
 

packer_test.go

@@ -79,6 +79,32 @@ func TestBoxPackerSuite(t *testing.T) {
  suite.Run(t, new(PackerSuit))
 }
 
+func (s *PackerSuit) TestEmptyBoxes() {
+ t := s.T()
+ t.Parallel()
+
+ packer := boxpacker3.NewPacker()
+
+ packResult := packer.Pack(nil, nil)
+ require.NotNil(t, packResult)
+ require.Len(t, packResult.Boxes, 0)
+ require.Len(t, packResult.UnfitItems, 0)
+}
+
+func (s *PackerSuit) TestEmptyItems() {
+ t := s.T()
+ t.Parallel()
+
+ packer := boxpacker3.NewPacker()
+
+ boxes := NewDefaultBoxList()
+
+ packResult := packer.Pack(boxes, nil)
+ require.NotNil(t, packResult)
+ require.Len(t, packResult.Boxes, len(boxes))
+ require.Len(t, packResult.UnfitItems, 0)
+}
+
 func (s *PackerSuit) TestMinBox() {
  t := s.T()
  t.Parallel()