expects: []file{{name: "baz/quux", mode: os.ModeDir}},
		},
	}
	for _, c := range cases {
		t.Run(c.desc, func(t *testing.T) {
			c.run(t, &utilfs.DefaultFs{})
		})
	}
}

func TestWriteTempDir(t *testing.T) {
	// writing a tmp dir is covered by TestReplaceDir, but we additionally test filename validation here
	c := test{
		desc: "invalid file key",
		err:  "invalid file key",