MM-34002: Improve AddUserToChannel (#17174)

* MM-34002: Improve AddUserToChannel

When we would add a user to a channel, we would
check whether the user is removed from that team or not.

During LDAP sync, this check is not required because the
team member would have just been created. Hence, we
pass a boolean flag to bypass the check.

And with that done, we can freely query the replica.

https://mattermost.atlassian.net/browse/MM-34002

```release-note
NONE
```

* Refactor code

* Rename a struct field

* fix double negative

app/slashcommands/command_invite.go

@@ -140,7 +140,9 @@ func (*InviteProvider) DoCommand(a *app.App, args *model.CommandArgs, message st
 		}
 	}
 
-	if _, err := a.AddChannelMember(userProfile.Id, channelToJoin, args.UserId, ""); err != nil {
+	if _, err := a.AddChannelMember(userProfile.Id, channelToJoin, app.ChannelMemberOpts{
+		UserRequestorID: args.UserId,
+	}); err != nil {
 		var text string
 		if err.Id == "api.channel.add_members.user_denied" {
 			text = args.T("api.command_invite.group_constrained_user_denied")

app/slashcommands/command_invite_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
+	"github.com/mattermost/mattermost-server/v5/app"
 	"github.com/mattermost/mattermost-server/v5/model"
 )
 
@@ -72,7 +73,7 @@ func TestInviteProvider(t *testing.T) {
 	deactivatedUserPublicChannel := "@" + deactivatedUser.Username + " ~" + channel.Name
 
 	groupChannel := th.createChannel(th.BasicTeam, model.CHANNEL_PRIVATE)
-	_, err = th.App.AddChannelMember(th.BasicUser.Id, groupChannel, "", "")
+	_, err = th.App.AddChannelMember(th.BasicUser.Id, groupChannel, app.ChannelMemberOpts{})
 	require.Nil(t, err)
 	groupChannel.GroupConstrained = model.NewBool(true)
 	groupChannel, _ = th.App.UpdateChannel(groupChannel)

app/slashcommands/command_leave_test.go

@@ -41,11 +41,11 @@ func TestLeaveProviderDoCommand(t *testing.T) {
 	guest := th.createGuest()
 
 	th.App.AddUserToTeam(th.BasicTeam.Id, th.BasicUser.Id, th.BasicUser.Id)
-	th.App.AddUserToChannel(th.BasicUser, publicChannel)
-	th.App.AddUserToChannel(th.BasicUser, privateChannel)
+	th.App.AddUserToChannel(th.BasicUser, publicChannel, false)
+	th.App.AddUserToChannel(th.BasicUser, privateChannel, false)
 	th.App.AddUserToTeam(th.BasicTeam.Id, guest.Id, guest.Id)
-	th.App.AddUserToChannel(guest, publicChannel)
-	th.App.AddUserToChannel(guest, defaultChannel)
+	th.App.AddUserToChannel(guest, publicChannel, false)
+	th.App.AddUserToChannel(guest, defaultChannel, false)
 
 	t.Run("Should error when no Channel ID in args", func(t *testing.T) {
 		args := &model.CommandArgs{

app/slashcommands/command_remove_test.go

@@ -35,8 +35,8 @@ func TestRemoveProviderDoCommand(t *testing.T) {
 
 	targetUser := th.createUser()
 	th.App.AddUserToTeam(th.BasicTeam.Id, targetUser.Id, targetUser.Id)
-	th.App.AddUserToChannel(targetUser, publicChannel)
-	th.App.AddUserToChannel(targetUser, privateChannel)
+	th.App.AddUserToChannel(targetUser, publicChannel, false)
+	th.App.AddUserToChannel(targetUser, privateChannel, false)
 
 	// Try a public channel *without* permission.
 	args := &model.CommandArgs{
@@ -49,7 +49,7 @@ func TestRemoveProviderDoCommand(t *testing.T) {
 	assert.Equal(t, "api.command_remove.permission.app_error", actual)
 
 	// Try a public channel *with* permission.
-	th.App.AddUserToChannel(th.BasicUser, publicChannel)
+	th.App.AddUserToChannel(th.BasicUser, publicChannel, false)
 	args = &model.CommandArgs{
 		T:         func(s string, args ...interface{}) string { return s },
 		ChannelId: publicChannel.Id,
@@ -70,7 +70,7 @@ func TestRemoveProviderDoCommand(t *testing.T) {
 	assert.Equal(t, "api.command_remove.permission.app_error", actual)
 
 	// Try a private channel *with* permission.
-	th.App.AddUserToChannel(th.BasicUser, privateChannel)
+	th.App.AddUserToChannel(th.BasicUser, privateChannel, false)
 	args = &model.CommandArgs{
 		T:         func(s string, args ...interface{}) string { return s },
 		ChannelId: privateChannel.Id,
@@ -110,7 +110,7 @@ func TestRemoveProviderDoCommand(t *testing.T) {
 	// Try a public channel with a deactivated user.
 	deactivatedUser := th.createUser()
 	th.App.AddUserToTeam(th.BasicTeam.Id, deactivatedUser.Id, deactivatedUser.Id)
-	th.App.AddUserToChannel(deactivatedUser, publicChannel)
+	th.App.AddUserToChannel(deactivatedUser, publicChannel, false)
 	th.App.UpdateActive(deactivatedUser, false)
 
 	args = &model.CommandArgs{

app/slashcommands/helper_test.go

@@ -358,7 +358,7 @@ func (th *TestHelper) linkUserToTeam(user *model.User, team *model.Team) {
 func (th *TestHelper) addUserToChannel(user *model.User, channel *model.Channel) *model.ChannelMember {
 	utils.DisableDebugLogForTest()
 
-	member, err := th.App.AddUserToChannel(user, channel)
+	member, err := th.App.AddUserToChannel(user, channel, false)
 	if err != nil {
 		panic(err)
 	}