added temp file method to utils/filesys

go/libraries/utils/filesys/fs.go

@@ -71,6 +71,9 @@ type WritableFS interface {
 
 	// MoveFile will move a file from the srcPath in the filesystem to the destPath
 	MoveFile(srcPath, destPath string) error
+
+	// TempDir returns the path of a new temporary directory.
+	TempDir() string
 }
 
 // FSIterCB specifies the signature of the function that will be called for every item found while iterating.

go/libraries/utils/filesys/fs_test.go

@@ -103,6 +103,20 @@ func TestFilesystems(t *testing.T) {
 			dataRead, err = fs.ReadFile(movedFilePath)
 			require.NoError(t, err)
 			require.Equal(t, dataRead, data)
+
+			tmp := fs.TempDir()
+			require.NotEmpty(t, tmp)
+			fp2 := filepath.Join(tmp, "data.txt")
+			wrc, err := fs.OpenForWrite(fp2, os.ModePerm)
+			require.NoError(t, err)
+			require.NoError(t, wrc.Close())
+
+			// Test writing/reading random data to tmp file
+			err = fs.WriteFile(fp2, data)
+			require.NoError(t, err)
+			dataRead, err = fs.ReadFile(fp2)
+			require.NoError(t, err)
+			require.Equal(t, dataRead, data)
 		})
 	}
 }

go/libraries/utils/filesys/inmemfs.go

@@ -16,8 +16,10 @@ package filesys
 
 import (
 	"bytes"
+	"encoding/base32"
 	"errors"
 	"io"
+	"math/rand"
 	"os"
 	"path/filepath"
 	"strings"
@@ -559,6 +561,13 @@ func (fs *InMemFS) LastModified(path string) (t time.Time, exists bool) {
 	return time.Time{}, false
 }
 
+func (fs *InMemFS) TempDir() string {
+	buf := make([]byte, 16)
+	rand.Read(buf)
+	s := base32.HexEncoding.EncodeToString(buf)
+	return "/var/folders/gc/" + s + "/T/"
+}
+
 func (fs *InMemFS) pathToNative(path string) string {
 	if len(path) >= 1 {
 		if path[0] == '.' {

go/libraries/utils/filesys/localfs.go

@@ -318,3 +318,7 @@ func (fs *localFS) LastModified(path string) (t time.Time, exists bool) {
 
 	return stat.ModTime(), true
 }
+
+func (fs *localFS) TempDir() string {
+	return os.TempDir()
+}