package cli import ( "strings" "testing" ) func replaceRequiredOnce(t *testing.T, input, old, replacement string) string { t.Helper() if count := strings.Count(input, old); count != 1 { t.Fatalf("replacement marker %q occurs %d times, want exactly once", old, count) } return strings.Replace(input, old, replacement, 1) } func emptyLookup(string) (string, bool) { return "", false }