br: fix incorrect uri for the file storage (#48453)

close #48452

br/pkg/storage/local.go

@@ -140,7 +140,7 @@ func (l *LocalStorage) WalkDir(_ context.Context, opt *WalkOption, fn func(strin
 
 // URI returns the base path as an URI with a file:/// prefix.
 func (l *LocalStorage) URI() string {
-	return LocalURIPrefix + "/" + l.base
+	return LocalURIPrefix + l.base
 }
 
 // Open a Reader by file path, path is a relative path to base path.

br/pkg/storage/local_test.go

@@ -157,6 +157,20 @@ func TestWalkDirSkipSubDir(t *testing.T) {
 	}))
 }
 
+func TestLocalURI(t *testing.T) {
+	ctx := context.Background()
+
+	url := "file:///tmp/folder"
+	sb, err := ParseBackend(url, &BackendOptions{})
+	require.NoError(t, err)
+
+	store, err := Create(ctx, sb, true)
+	require.NoError(t, err)
+
+	obtained := store.URI()
+	require.Equal(t, url, obtained)
+}
+
 func TestLocalFileReadRange(t *testing.T) {
 	ctx := context.Background()
 	dir := t.TempDir()