wantPrefix, wantSuffix string
	}{
		{"ioutil_test", "ioutil_test", ""},
		{"ioutil_test*", "ioutil_test", ""},
		{"ioutil_test*xyz", "ioutil_test", "xyz"},
	}

	dir := os.TempDir()

	runTestTempDir := func(t *testing.T, pattern, wantRePat string) {
		name, err := TempDir(dir, pattern)
		if name == "" || err != nil {
			t.Fatalf("TempDir(dir, `ioutil_test`) = %v, %v", name, err)
		}
		defer os.Remove(name)