feat(windows): Set .qri-ref as hidden in Windows

fsi/fsi.go

@@ -170,8 +170,11 @@ func (fsi *FSI) getRepoRef(refStr string) (ref repo.DatasetRef, err error) {
 }
 
 func writeLinkFile(dir, linkstr string) error {
-	dir = filepath.Join(dir, QriRefFilename)
-	return ioutil.WriteFile(dir, []byte(linkstr), os.ModePerm)
+	filepath := filepath.Join(dir, QriRefFilename)
+	if err := ioutil.WriteFile(filepath, []byte(linkstr), os.ModePerm); err != nil {
+		return err
+	}
+	return setFileHidden(filepath)
 }
 
 func removeLinkFile(dir string) error {

fsi/set_file.go

@@ -0,0 +1,18 @@
+// +build !windows
+
+package fsi
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+)
+
+// setFileHidden ensures the filename begins with a dot. Other OSes may do more
+func setFileHidden(path string) error {
+	basename := filepath.Base(path)
+	if !strings.HasPrefix(basename, ".") {
+		return fmt.Errorf("hidden files must begin with \".\"")
+	}
+	return nil
+}

fsi/set_file_windows.go

@@ -0,0 +1,21 @@
+package fsi
+
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+	"syscall"
+)
+
+// setFileHidden sets the hidden attribute on the given file. Windows specific functionality
+func setFileHidden(path string) error {
+	basename := filepath.Base(path)
+	if !strings.HasPrefix(basename, ".") {
+		return fmt.Errorf("hidden files must begin with \".\"")
+	}
+	filenamePtr, err := syscall.UTF16PtrFromString(path)
+	if err != nil {
+		return err
+	}
+	return syscall.SetFileAttributes(filenamePtr, syscall.FILE_ATTRIBUTE_HIDDEN)
+}