//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris

package main

import (
	"os/user"
	"testing"
)

// Usernames must not contain a number sign.
func TestEmptyString(t *testing.T) {
	if chuser("", "") == nil {
		t.Fatal("the empty string is not a valid user")
	}
}

// Either omit delimiter and group, or omit both.
func TestEmptyGroup(t *testing.T) {
	if chuser("0:", "") == nil {
		t.Fatal("the empty group is not allowed")
	}
}

// Either user only or user and group.
func TestGroupOnly(t *testing.T) {
	if chuser(":0", "") == nil {
		t.Fatal("group only is not allowed")
	}
}

// Usenames must not contain the number sign.
func TestInvalidUsername(t *testing.T) {
	const username = "#user"
	if chuser(username, "") == nil {
		t.Fatalf("'%s' is not a valid username", username)
	}
}

// User IDs must be non-negative.
func TestInvalidUserid(t *testing.T) {
	if chuser("-1", "") == nil {
		t.Fatal("User ID cannot be negative")
	}
}

// Change to the current user by ID.
func TestCurrentUserid(t *testing.T) {
	usr, err := user.Current()
	if err != nil {
		t.Fatal(err)
	}

	if usr.Uid != "0" {
		t.Skip("setgroups(2): Only the superuser may set new groups.")
	}

	if err = chuser(usr.Uid, ""); err != nil {
		t.Fatal(err)
	}
}

// Change to a common user by name.
func TestCommonUsername(t *testing.T) {
	usr, err := user.Current()
	if err != nil {
		t.Fatal(err)
	}

	if usr.Uid != "0" {
		t.Skip("setgroups(2): Only the superuser may set new groups.")
	}

	if err := chuser("nobody", ""); err != nil {
		if _, ok := err.(user.UnknownUserError); ok {
			t.Skip(err)
		}
		t.Fatal(err)
	}
}
