if want, got := pre, out.String(); want != got {
		t.Errorf("want output %q, got %q", want, got)
	}
	if want := 1; want != code {
		t.Errorf("want exit code %d, got %d", want, code)
	}
}

func TestExitCodeMissing(t *testing.T) {
	var wantErr *regexp.Regexp
	check := func(text string) {
		t.Helper()
		var out strings.Builder
		f, exitStr := newExitCodeFilter(&out)
		if want := "exitcode="; want != exitStr {