package mq

import (
	"errors"
	"fmt"
	"testing"
)

func TestPermanentHandlerErrorClassification(t *testing.T) {
	cause := errors.New("invalid inbound command")
	if got := Permanent(nil); got != nil {
		t.Fatalf("nil permanent error = %v, want nil", got)
	}
	permanent := Permanent(cause)
	if !errors.Is(permanent, cause) {
		t.Fatal("permanent error lost its cause")
	}
	if !IsPermanent(permanent) || !IsPermanent(fmt.Errorf("handler: %w", permanent)) {
		t.Fatal("wrapped permanent handler error must reject delivery")
	}
	if IsPermanent(cause) || IsPermanent(nil) {
		t.Fatal("transient or absent handler error must not reject delivery")
	}
}