Break the fs package up into smaller parts.

The purpose of this is to make it easier to maintain and eventually to
allow the rclone backends to be re-used in other projects without
having to use the rclone configuration system.

The new code layout is documented in CONTRIBUTING.

fs/operations/listdirsorted_test.go

@@ -0,0 +1,104 @@
+package operations_test
+
+import (
+	"testing"
+
+	"github.com/ncw/rclone/fs"
+	"github.com/ncw/rclone/fs/filter"
+	"github.com/ncw/rclone/fs/list"
+	"github.com/ncw/rclone/fstest"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestListDirSorted is integration testing code in fs/list/list.go
+// which can't be tested there due to import loops.
+func TestListDirSorted(t *testing.T) {
+	r := fstest.NewRun(t)
+	defer r.Finalise()
+
+	filter.Active.Opt.MaxSize = 10
+	defer func() {
+		filter.Active.Opt.MaxSize = -1
+	}()
+
+	files := []fstest.Item{
+		r.WriteObject("a.txt", "hello world", t1),
+		r.WriteObject("zend.txt", "hello", t1),
+		r.WriteObject("sub dir/hello world", "hello world", t1),
+		r.WriteObject("sub dir/hello world2", "hello world", t1),
+		r.WriteObject("sub dir/ignore dir/.ignore", "", t1),
+		r.WriteObject("sub dir/ignore dir/should be ignored", "to ignore", t1),
+		r.WriteObject("sub dir/sub sub dir/hello world3", "hello world", t1),
+	}
+	fstest.CheckItems(t, r.Fremote, files...)
+	var items fs.DirEntries
+	var err error
+
+	// Turn the DirEntry into a name, ending with a / if it is a
+	// dir
+	str := func(i int) string {
+		item := items[i]
+		name := item.Remote()
+		switch item.(type) {
+		case fs.Object:
+		case fs.Directory:
+			name += "/"
+		default:
+			t.Fatalf("Unknown type %+v", item)
+		}
+		return name
+	}
+
+	items, err = list.DirSorted(r.Fremote, true, "")
+	require.NoError(t, err)
+	require.Len(t, items, 3)
+	assert.Equal(t, "a.txt", str(0))
+	assert.Equal(t, "sub dir/", str(1))
+	assert.Equal(t, "zend.txt", str(2))
+
+	items, err = list.DirSorted(r.Fremote, false, "")
+	require.NoError(t, err)
+	require.Len(t, items, 2)
+	assert.Equal(t, "sub dir/", str(0))
+	assert.Equal(t, "zend.txt", str(1))
+
+	items, err = list.DirSorted(r.Fremote, true, "sub dir")
+	require.NoError(t, err)
+	require.Len(t, items, 4)
+	assert.Equal(t, "sub dir/hello world", str(0))
+	assert.Equal(t, "sub dir/hello world2", str(1))
+	assert.Equal(t, "sub dir/ignore dir/", str(2))
+	assert.Equal(t, "sub dir/sub sub dir/", str(3))
+
+	items, err = list.DirSorted(r.Fremote, false, "sub dir")
+	require.NoError(t, err)
+	require.Len(t, items, 2)
+	assert.Equal(t, "sub dir/ignore dir/", str(0))
+	assert.Equal(t, "sub dir/sub sub dir/", str(1))
+
+	// testing ignore file
+	filter.Active.Opt.ExcludeFile = ".ignore"
+
+	items, err = list.DirSorted(r.Fremote, false, "sub dir")
+	require.NoError(t, err)
+	require.Len(t, items, 1)
+	assert.Equal(t, "sub dir/sub sub dir/", str(0))
+
+	items, err = list.DirSorted(r.Fremote, false, "sub dir/ignore dir")
+	require.NoError(t, err)
+	require.Len(t, items, 0)
+
+	items, err = list.DirSorted(r.Fremote, true, "sub dir/ignore dir")
+	require.NoError(t, err)
+	require.Len(t, items, 2)
+	assert.Equal(t, "sub dir/ignore dir/.ignore", str(0))
+	assert.Equal(t, "sub dir/ignore dir/should be ignored", str(1))
+
+	filter.Active.Opt.ExcludeFile = ""
+	items, err = list.DirSorted(r.Fremote, false, "sub dir/ignore dir")
+	require.NoError(t, err)
+	require.Len(t, items, 2)
+	assert.Equal(t, "sub dir/ignore dir/.ignore", str(0))
+	assert.Equal(t, "sub dir/ignore dir/should be ignored", str(1))
+}