Add optional interface DirCacheFlush for making the tests more reliable

This is defined for the users of dircache drive, onedrive, and acd.

This helps fix the DirMove tests on acd.

amazonclouddrive/amazonclouddrive.go

@@ -636,6 +636,11 @@ func (f *Fs) Move(src fs.Object, remote string) (fs.Object, error) {
 	}
 	fs.Debug(src, "Attempting to move to %q", remote)
 	return srcObj.move(remote, false)
+
+// DirCacheFlush resets the directory cache - used in testing as an
+// optional interface
+func (f *Fs) DirCacheFlush() {
+	f.dirCache.ResetRoot()
 }
 
 // DirMove moves src directory to this remote using server side move
@@ -1124,6 +1129,7 @@ var (
 	//	_ fs.Copier   = (*Fs)(nil)
 	_ fs.Mover           = (*Fs)(nil)
 	_ fs.DirMover        = (*Fs)(nil)
+	_ fs.DirCacheFlusher = (*Fs)(nil)
 	_ fs.Object          = (*Object)(nil)
 	_ fs.MimeTyper       = &Object{}
 )

drive/drive.go

@@ -799,6 +799,12 @@ func (f *Fs) DirMove(src fs.Fs) error {
 	return nil
 }
 
+// DirCacheFlush resets the directory cache - used in testing as an
+// optional interface
+func (f *Fs) DirCacheFlush() {
+	f.dirCache.ResetRoot()
+}
+
 // Hashes returns the supported hash sets.
 func (f *Fs) Hashes() fs.HashSet {
 	return fs.HashSet(fs.HashMD5)
@@ -1084,6 +1090,7 @@ var (
 	_ fs.Copier          = (*Fs)(nil)
 	_ fs.Mover           = (*Fs)(nil)
 	_ fs.DirMover        = (*Fs)(nil)
+	_ fs.DirCacheFlusher = (*Fs)(nil)
 	_ fs.PutUncheckeder  = (*Fs)(nil)
 	_ fs.Object          = (*Object)(nil)
 	_ fs.MimeTyper       = &Object{}

fs/fs.go

@@ -275,6 +275,13 @@ type UnWrapper interface {
 	UnWrap() Fs
 }
 
+// DirCacheFlusher is an optional interface for Fs
+type DirCacheFlusher interface {
+	// DirCacheFlush resets the directory cache - used in testing
+	// as an optional interface
+	DirCacheFlush()
+}
+
 // PutUncheckeder is an optional interface for Fs
 type PutUncheckeder interface {
 	// Put in to the remote path with the modTime given of the given size

fstest/fstest.go

@@ -175,6 +175,10 @@ func CheckListingWithPrecision(t *testing.T, f fs.Fs, items []Item, expectedDirs
 		sleep *= 2
 		t.Logf("Sleeping for %v for list eventual consistency: %d/%d", sleep, i, retries)
 		time.Sleep(sleep)
+		if do, ok := f.(fs.DirCacheFlusher); ok {
+			t.Logf("Flushing the directory cache")
+			do.DirCacheFlush()
+		}
 	}
 	for _, obj := range objs {
 		require.NotNil(t, obj)

onedrive/onedrive.go

@@ -635,6 +635,12 @@ func (f *Fs) Purge() error {
 	return f.purgeCheck("", false)
 }
 
+// DirCacheFlush resets the directory cache - used in testing as an
+// optional interface
+func (f *Fs) DirCacheFlush() {
+	f.dirCache.ResetRoot()
+}
+
 // Hashes returns the supported hash sets.
 func (f *Fs) Hashes() fs.HashSet {
 	return fs.HashSet(fs.HashSHA1)
@@ -960,6 +966,7 @@ var (
 	_ fs.Copier = (*Fs)(nil)
 	// _ fs.Mover    = (*Fs)(nil)
 	// _ fs.DirMover = (*Fs)(nil)
+	_ fs.DirCacheFlusher = (*Fs)(nil)
 	_ fs.Object          = (*Object)(nil)
 	_ fs.MimeTyper       = &Object{}
 )