You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: command_leave_test.go
    path of file: ./repos/mattermost/server/channels/app/slashcommands
    
    the code of the file until where you have to start completion: // Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.

package slashcommands

import (
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"github.com/mattermost/mattermost/server/public/model"
)

func TestLeaveProviderDoCommand(t *testing.T) {
	th := setup(t).initBasic()
	defer th.tearDown()

	lp := LeaveProvider{}

	publicChannel, _ := th.App.CreateChannel(th.Context, &model.Channel{
		DisplayName: "AA",
		Name:        "aa" + model.NewId() + "a",
		Type:        model.ChannelTypeOpen,
		TeamId:      th.BasicTeam.Id,
		CreatorId:   th.BasicUser.Id,
	}, false)

	privateChannel, _ := th.App.CreateChannel(th.Context, &model.Channel{
		DisplayName: "BB",
		Name:        "aa" + model.NewId() + "a",
		Type:        model.ChannelTypeOpen,
		TeamId:      th.BasicTeam
    
func TestLeaveProviderDoCommand(t *testing.T) {
	th := setup(t).initBasic()
	defer th.tearDown()

	lp := LeaveProvider{}

	publicChannel, _ := th.App.CreateChannel(th.Context, &model.Channel{
		DisplayName: "AA",
		Name:        "aa" + model.NewId() + "a",
		Type:        model.ChannelTypeOpen,
		TeamId:      th.BasicTeam.Id,
		CreatorId:   th.BasicUser.Id,
	}, false)

	privateChannel, _ := th.App.CreateChannel(th.Context, &model.Channel{
		DisplayName: "BB",
		Name:        "aa" + model.NewId() + "a",
		Type:        model.ChannelTypeOpen,
		TeamId:      th.BasicTeam.Id,
		CreatorId:   th.BasicUser.Id,
	}, false)

	defaultChannel, err := th.App.GetChannelByName(th.Context, model.DefaultChannelName, th.BasicTeam.Id, false)
	require.Nil(t, err)

	guest := th.createGuest()

	th.App.AddUserToTeam(th.Context, th.BasicTeam.Id, th.BasicUser.Id, th.BasicUser.Id)
	th.App.AddUserToChannel(th.Context, th.BasicUser, publicChannel, false)
	th.App.AddUserToChannel(th.Context, th.BasicUser, privateChannel, false)
	th.App.AddUserToTeam(th.Context, th.BasicTeam.Id, guest.Id, guest.Id)
	th.App.AddUserToChannel(th.Context, guest, publicChannel, false)
	th.App.AddUserToChannel(th.Context, guest, defaultChannel, false)

	t.Run("Should error when no Channel ID in args", func(t *testing.T) {
		args := &model.CommandArgs{
			UserId: th.BasicUser.Id,
			T:      func(s string, args ...any) string { return s },
		}
		actual := lp.DoCommand(th.App, th.Context, args, "")
		assert.Equal(t, "api.command_leave.fail.app_error", actual.Text)
		assert.Equal(t, model.CommandResponseTypeEphemeral, actual.ResponseType)
	})

	t.Run("Should error when no Team ID in args", func(t *testing.T) {
		args := &model.CommandArgs{
			UserId:    th.BasicUser.Id,
			ChannelId: publicChannel.Id,
			T:         func(s string, args ...any) string { return s },
		}
		actual := lp.DoCommand(th.App, th.Context, args, "")
		assert.Equal(t, "api.command_leave.fail.app_error", actual.Text)
		assert.Equal(t, model.CommandResponseTypeEphemeral, actual.ResponseType)
	})

	t.Run("Leave a public channel", func(t *testing.T) {
		args := &model.CommandArgs{
			UserId:    th.BasicUser.Id,
			ChannelId: publicChannel.Id,
			T:         func(s string, args ...any) string { return s },
			TeamId:    th.BasicTeam.Id,
			SiteURL:   "http://localhost:8065",
		}
		actual := lp.DoCommand(th.App, th.Context, args, "")
		assert.Equal(t, "", actual.Text)
		assert.Equal(t, args.SiteURL+"/"+th.BasicTeam.Name+"/channels/"+model.DefaultChannelName, actual.GotoLocation)
		assert.Equal(t, "", actual.ResponseType)

		_, err = th.App.GetChannelMember(th.Context, publicChannel.Id, th.BasicUser.Id)
		assert.NotNil(t, err)
		assert.NotNil(t, err.Id, "app.channel.get_member.missing.app_error")
	})

	t.Run("Leave a private channel", func(t *testing.T) {
		args := &model.CommandArgs{
			UserId:    th.BasicUser.Id,
			ChannelId: privateChannel.Id,
			T:         func(s string, args ...any) string { return s },
			TeamId:    th.BasicTeam.Id,
			SiteURL:   "http://localhost:8065",
		}
		actual := lp.DoCommand(th.App, th.Context, args, "")
		assert.Equal(t, "", actual.Text)
	})

	t.Run("Should not leave a default channel", func(t *testing.T) {
		args := &model.CommandArgs{
			UserId:    th.BasicUser.Id,
			ChannelId: defaultChannel.Id,
			T:         func(s string, args ...any) string { return s },
			TeamId:    th.BasicTeam.Id,
			SiteURL:   "http://localhost:8065",
		}
		actual := lp.DoCommand(th.App, th.Context, args, "")
		assert.Equal(t, "api.channel.leave.default.app_error", actual.Text)
	})

	t.Run("Should allow to leave a default channel if user is guest", func(t *testing.T) {
		args := &model.CommandArgs{
			UserId:    guest.Id,
			ChannelId: defaultChannel.Id,
			T:         func(s string, args ...any) string { return s },
			TeamId:    th.BasicTeam.Id,
			SiteURL:   "http://localhost:8065",
		}
		actual := lp.DoCommand(th.App, th.Context, args, "")
		assert.Equal(t, "", actual.Text)
		assert.Equal(t, args.SiteURL+"/"+th.BasicTeam.Name+"/channels/"+publicChannel.Name, actual.GotoLocation)
		assert.Equal(t, "", actual.ResponseType)

		_, err = th.App.GetChannelMember(th.Context, defaultChannel.Id, guest.Id)
		assert.NotNil(t, err)
		assert.NotNil(t, err.Id, "app.channel.get_member.missing.app_error")
	})

	t.Run("Should redirect to the team if is the last channel", func(t *testing.T) {
		args := &model.CommandArgs{
			UserId:    guest.Id,
			ChannelId: publicChannel.Id,
			T:         func(s string, args ...any) string { return s },
			TeamId:    th.BasicTeam.Id,
			SiteURL:   "http://localhost:8065",
		}
		actual := lp.DoCommand(th.App, th.Context, args, "")
		assert.Equal(t, "", actual.Text)
		assert.Equal(t, args.SiteURL+"/", actual.GotoLocation)
		assert.Equal(t, "", actual.ResponseType)

		_, err = th.App.GetChannelMember(th.Context, publicChannel.Id, guest.Id)
		assert.NotNil(t, err)
		assert.NotNil(t, err.Id, "app.channel.get_member.missing.app_error")
	})
}