lib/versioner: Minor fixes in comments and error message (#9031)

* lib/versioner: Factor out DefaultPath constant.

Replace several instances where .stversions is named literally to all
use the same definition in the versioner package.  Exceptions are the
packages where a cyclic dependency on versioner is impossible, or some
tests which combine the versions base path with other components.

* lib/versioner: Fix comment about trash can in simple versioner.

* lib/versioner: Fix wrong versioning type string in error message.

The error message shows the folder type instead of the versioning
type, although the correct field is used in the comparison.

lib/fs/filesystem.go

@@ -293,7 +293,8 @@ func NewFilesystem(fsType FilesystemType, uri string, opts ...Option) Filesystem
 // root, represents an internal file that should always be ignored. The file
 // path must be clean (i.e., in canonical shortest form).
 func IsInternal(file string) bool {
-	// fs cannot import config, so we hard code .stfolder here (config.DefaultMarkerName)
+	// fs cannot import config or versioner, so we hard code .stfolder
+	// (config.DefaultMarkerName) and .stversions (versioner.DefaultPath)
 	internals := []string{".stfolder", ".stignore", ".stversions"}
 	for _, internal := range internals {
 		if file == internal {

lib/model/model.go

@@ -399,7 +399,7 @@ func (m *model) addAndStartFolderLockedWithIgnores(cfg config.FolderConfiguratio
 	// These are our metadata files, and they should always be hidden.
 	ffs := cfg.Filesystem(nil)
 	_ = ffs.Hide(config.DefaultMarkerName)
-	_ = ffs.Hide(".stversions")
+	_ = ffs.Hide(versioner.DefaultPath)
 	_ = ffs.Hide(".stignore")
 
 	var ver versioner.Versioner

lib/model/model_test.go

@@ -2647,7 +2647,7 @@ func TestVersionRestore(t *testing.T) {
 			file = filepath.FromSlash(file)
 		}
 		tag := version.In(time.Local).Truncate(time.Second).Format(versioner.TimeFormat)
-		taggedName := filepath.Join(".stversions", versioner.TagFilename(file, tag))
+		taggedName := filepath.Join(versioner.DefaultPath, versioner.TagFilename(file, tag))
 		fd, err := filesystem.Open(file)
 		if err != nil {
 			t.Error(err)
@@ -2680,7 +2680,7 @@ func TestVersionRestore(t *testing.T) {
 		}
 		for _, version := range versions {
 			if version.VersionTime.Equal(beforeRestore) || version.VersionTime.After(beforeRestore) {
-				fd, err := filesystem.Open(".stversions/" + versioner.TagFilename(file, version.VersionTime.Format(versioner.TimeFormat)))
+				fd, err := filesystem.Open(versioner.DefaultPath + "/" + versioner.TagFilename(file, version.VersionTime.Format(versioner.TimeFormat)))
 				must(t, err)
 				defer fd.Close()
 

lib/versioner/simple.go

@@ -32,7 +32,7 @@ type simple struct {
 func newSimple(cfg config.FolderConfiguration) Versioner {
 	var keep, err = strconv.Atoi(cfg.Versioning.Params["keep"])
 	cleanoutDays, _ := strconv.Atoi(cfg.Versioning.Params["cleanoutDays"])
-	// On error we default to 0, "do not clean out the trash can"
+	// On error we default to 0, "do not clean out the versioned items"
 
 	if err != nil {
 		keep = 5 // A reasonable default

lib/versioner/simple_test.go

@@ -81,7 +81,7 @@ func TestSimpleVersioningVersionCount(t *testing.T) {
 			t.Error(err)
 		}
 
-		n, err := fs.DirNames(".stversions")
+		n, err := fs.DirNames(DefaultPath)
 		if err != nil {
 			t.Error(err)
 		}

lib/versioner/util.go

@@ -28,6 +28,10 @@ var (
 	errFileAlreadyExists = errors.New("file already exists")
 )
 
+const (
+	DefaultPath = ".stversions"
+)
+
 // TagFilename inserts ~tag just before the extension of the filename.
 func TagFilename(name, tag string) string {
 	dir, file := filepath.Dir(name), filepath.Base(name)
@@ -258,7 +262,7 @@ func restoreFile(method fs.CopyRangeMethod, src, dst fs.Filesystem, filePath str
 func versionerFsFromFolderCfg(cfg config.FolderConfiguration) (versionsFs fs.Filesystem) {
 	folderFs := cfg.Filesystem(nil)
 	if cfg.Versioning.FSPath == "" {
-		versionsFs = fs.NewFilesystem(folderFs.Type(), filepath.Join(folderFs.URI(), ".stversions"))
+		versionsFs = fs.NewFilesystem(folderFs.Type(), filepath.Join(folderFs.URI(), DefaultPath))
 	} else if cfg.Versioning.FSType == fs.FilesystemTypeBasic && !filepath.IsAbs(cfg.Versioning.FSPath) {
 		// We only know how to deal with relative folders for basic filesystems, as that's the only one we know
 		// how to check if it's absolute or relative.

lib/versioner/versioner.go

@@ -44,7 +44,7 @@ const (
 func New(cfg config.FolderConfiguration) (Versioner, error) {
 	fac, ok := factories[cfg.Versioning.Type]
 	if !ok {
-		return nil, fmt.Errorf("requested versioning type %q does not exist", cfg.Type)
+		return nil, fmt.Errorf("requested versioning type %q does not exist", cfg.Versioning.Type)
 	}
 
 	return &versionerWithErrorContext{