MM-21357: Use typed constant for channel types (#17928)

* MM-21357: Use typed constant for channel types

https://mattermost.atlassian.net/browse/MM-21357

```release-note
- Introduced a new type ChannelType for all channel types.
- Updated the Client4.UpdateChannelPrivacy method to ChannelType.
```

* Address review comments

```release-note
NONE
```

* telemetry fix

```release-note
NONE
```

api4/apitestlib.go

@@ -636,11 +636,11 @@ func (th *TestHelper) CreatePrivateChannel() *model.Channel {
 	return th.CreateChannelWithClient(th.Client, model.ChannelTypePrivate)
 }
 
-func (th *TestHelper) CreateChannelWithClient(client *model.Client4, channelType string) *model.Channel {
+func (th *TestHelper) CreateChannelWithClient(client *model.Client4, channelType model.ChannelType) *model.Channel {
 	return th.CreateChannelWithClientAndTeam(client, channelType, th.BasicTeam.Id)
 }
 
-func (th *TestHelper) CreateChannelWithClientAndTeam(client *model.Client4, channelType string, teamId string) *model.Channel {
+func (th *TestHelper) CreateChannelWithClientAndTeam(client *model.Client4, channelType model.ChannelType, teamId string) *model.Channel {
 	id := model.NewId()
 
 	channel := &model.Channel{

api4/channel.go

@@ -283,7 +283,7 @@ func updateChannelPrivacy(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	props := model.StringInterfaceFromJson(r.Body)
 	privacy, ok := props["privacy"].(string)
-	if !ok || (privacy != model.ChannelTypeOpen && privacy != model.ChannelTypePrivate) {
+	if !ok || (model.ChannelType(privacy) != model.ChannelTypeOpen && model.ChannelType(privacy) != model.ChannelTypePrivate) {
 		c.SetInvalidParam("privacy")
 		return
 	}
@@ -299,17 +299,17 @@ func updateChannelPrivacy(c *Context, w http.ResponseWriter, r *http.Request) {
 	auditRec.AddMeta("channel", channel)
 	auditRec.AddMeta("new_type", privacy)
 
-	if privacy == model.ChannelTypeOpen && !c.App.SessionHasPermissionToChannel(*c.AppContext.Session(), c.Params.ChannelId, model.PermissionConvertPrivateChannelToPublic) {
+	if model.ChannelType(privacy) == model.ChannelTypeOpen && !c.App.SessionHasPermissionToChannel(*c.AppContext.Session(), c.Params.ChannelId, model.PermissionConvertPrivateChannelToPublic) {
 		c.SetPermissionError(model.PermissionConvertPrivateChannelToPublic)
 		return
 	}
 
-	if privacy == model.ChannelTypePrivate && !c.App.SessionHasPermissionToChannel(*c.AppContext.Session(), c.Params.ChannelId, model.PermissionConvertPublicChannelToPrivate) {
+	if model.ChannelType(privacy) == model.ChannelTypePrivate && !c.App.SessionHasPermissionToChannel(*c.AppContext.Session(), c.Params.ChannelId, model.PermissionConvertPublicChannelToPrivate) {
 		c.SetPermissionError(model.PermissionConvertPublicChannelToPrivate)
 		return
 	}
 
-	if channel.Name == model.DefaultChannelName && privacy == model.ChannelTypePrivate {
+	if channel.Name == model.DefaultChannelName && model.ChannelType(privacy) == model.ChannelTypePrivate {
 		c.Err = model.NewAppError("updateChannelPrivacy", "api.channel.update_channel_privacy.default_channel_error", nil, "", http.StatusBadRequest)
 		return
 	}
@@ -321,7 +321,7 @@ func updateChannelPrivacy(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 	auditRec.AddMeta("user", user)
 
-	channel.Type = privacy
+	channel.Type = model.ChannelType(privacy)
 
 	updatedChannel, err := c.App.UpdateChannelPrivacy(c.AppContext, channel, user)
 	if err != nil {

api4/channel_local.go

@@ -68,7 +68,7 @@ func localUpdateChannelPrivacy(c *Context, w http.ResponseWriter, r *http.Reques
 
 	props := model.StringInterfaceFromJson(r.Body)
 	privacy, ok := props["privacy"].(string)
-	if !ok || (privacy != model.ChannelTypeOpen && privacy != model.ChannelTypePrivate) {
+	if !ok || (model.ChannelType(privacy) != model.ChannelTypeOpen && model.ChannelType(privacy) != model.ChannelTypePrivate) {
 		c.SetInvalidParam("privacy")
 		return
 	}
@@ -84,11 +84,11 @@ func localUpdateChannelPrivacy(c *Context, w http.ResponseWriter, r *http.Reques
 	auditRec.AddMeta("channel", channel)
 	auditRec.AddMeta("new_type", privacy)
 
-	if channel.Name == model.DefaultChannelName && privacy == model.ChannelTypePrivate {
+	if channel.Name == model.DefaultChannelName && model.ChannelType(privacy) == model.ChannelTypePrivate {
 		c.Err = model.NewAppError("updateChannelPrivacy", "api.channel.update_channel_privacy.default_channel_error", nil, "", http.StatusBadRequest)
 		return
 	}
-	channel.Type = privacy
+	channel.Type = model.ChannelType(privacy)
 
 	updatedChannel, err := c.App.UpdateChannelPrivacy(c.AppContext, channel, nil)
 	if err != nil {

api4/channel_test.go

@@ -1850,7 +1850,7 @@ func TestUpdateChannelPrivacy(t *testing.T) {
 	type testTable []struct {
 		name            string
 		channel         *model.Channel
-		expectedPrivacy string
+		expectedPrivacy model.ChannelType
 	}
 
 	t.Run("Should get a forbidden response if not logged in", func(t *testing.T) {

app/channel.go

@@ -725,7 +725,7 @@ func (a *App) postChannelPrivacyMessage(c *request.Context, user *model.User, ch
 		authorUsername = systemBot.Username
 	}
 
-	message := (map[string]string{
+	message := (map[model.ChannelType]string{
 		model.ChannelTypeOpen:    i18n.T("api.channel.change_channel_privacy.private_to_public"),
 		model.ChannelTypePrivate: i18n.T("api.channel.change_channel_privacy.public_to_private"),
 	})[channel.Type]
@@ -1080,7 +1080,7 @@ func (a *App) PatchChannelModerationsForChannel(channel *model.Channel, channelM
 	return buildChannelModerations(channel.Type, memberRole, guestRole, higherScopedMemberRole, higherScopedGuestRole), nil
 }
 
-func buildChannelModerations(channelType string, memberRole *model.Role, guestRole *model.Role, higherScopedMemberRole *model.Role, higherScopedGuestRole *model.Role) []*model.ChannelModeration {
+func buildChannelModerations(channelType model.ChannelType, memberRole *model.Role, guestRole *model.Role, higherScopedMemberRole *model.Role, higherScopedGuestRole *model.Role) []*model.ChannelModeration {
 	var memberPermissions, guestPermissions, higherScopedMemberPermissions, higherScopedGuestPermissions map[string]bool
 	if memberRole != nil {
 		memberPermissions = memberRole.GetChannelModeratedPermissions(channelType)

app/helper_test.go

@@ -316,7 +316,7 @@ func (th *TestHelper) CreatePrivateChannel(team *model.Team) *model.Channel {
 	return th.createChannel(team, model.ChannelTypePrivate)
 }
 
-func (th *TestHelper) createChannel(team *model.Team, channelType string, options ...ChannelOption) *model.Channel {
+func (th *TestHelper) createChannel(team *model.Team, channelType model.ChannelType, options ...ChannelOption) *model.Channel {
 	id := model.NewId()
 
 	channel := &model.Channel{

app/import_functions_test.go

@@ -610,10 +610,11 @@ func TestImportImportChannel(t *testing.T) {
 	require.NoError(t, nErr, "Failed to get team count.")
 
 	// Do an invalid channel in dry-run mode.
+	chanOpen := model.ChannelTypeOpen
 	data := ChannelImportData{
 		Team:        &teamName,
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanOpen,
 		Header:      ptrStr("Channe Header"),
 		Purpose:     ptrStr("Channel Purpose"),
 		Scheme:      &scheme1.Name,
@@ -678,8 +679,9 @@ func TestImportImportChannel(t *testing.T) {
 	assert.Equal(t, scheme1.Id, *channel.SchemeId)
 
 	// Alter all the fields of that channel.
+	cTypePr := model.ChannelTypePrivate
 	data.DisplayName = ptrStr("Chaned Disp Name")
-	data.Type = ptrStr(model.ChannelTypePrivate)
+	data.Type = &cTypePr
 	data.Header = ptrStr("New Header")
 	data.Purpose = ptrStr("New Purpose")
 	data.Scheme = &scheme2.Name
@@ -874,11 +876,12 @@ func TestImportImportUser(t *testing.T) {
 	require.Nil(t, appErr, "Failed to get team from database.")
 
 	channelName := model.NewId()
+	chanTypeOpen := model.ChannelTypeOpen
 	th.App.importChannel(th.Context, &ChannelImportData{
 		Team:        &teamName,
 		Name:        &channelName,
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 	}, false)
 	channel, appErr := th.App.GetChannelByName(channelName, team.Id, false)
 	require.Nil(t, appErr, "Failed to get channel from database.")
@@ -1396,7 +1399,7 @@ func TestImportImportUser(t *testing.T) {
 		Team:        &teamName,
 		Name:        ptrStr(model.NewId()),
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 		Header:      ptrStr("Channe Header"),
 		Purpose:     ptrStr("Channel Purpose"),
 	}
@@ -1939,11 +1942,12 @@ func TestImportimportMultiplePostLines(t *testing.T) {
 
 	// Create a Channel.
 	channelName := model.NewId()
+	chanTypeOpen := model.ChannelTypeOpen
 	th.App.importChannel(th.Context, &ChannelImportData{
 		Team:        &teamName,
 		Name:        &channelName,
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 	}, false)
 	channel, err := th.App.GetChannelByName(channelName, team.Id, false)
 	require.Nil(t, err, "Failed to get channel from database.")
@@ -2418,7 +2422,7 @@ func TestImportimportMultiplePostLines(t *testing.T) {
 		Team:        &teamName2,
 		Name:        &channelName,
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 	}, false)
 	_, err = th.App.GetChannelByName(channelName, team2.Id, false)
 	require.Nil(t, err, "Failed to get channel from database.")
@@ -2477,11 +2481,12 @@ func TestImportImportPost(t *testing.T) {
 
 	// Create a Channel.
 	channelName := model.NewId()
+	chanTypeOpen := model.ChannelTypeOpen
 	th.App.importChannel(th.Context, &ChannelImportData{
 		Team:        &teamName,
 		Name:        &channelName,
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 	}, false)
 	channel, appErr := th.App.GetChannelByName(channelName, team.Id, false)
 	require.Nil(t, appErr, "Failed to get channel from database.")
@@ -3920,11 +3925,12 @@ func TestImportPostAndRepliesWithAttachments(t *testing.T) {
 
 	// Create a Channel.
 	channelName := model.NewId()
+	chanTypeOpen := model.ChannelTypeOpen
 	th.App.importChannel(th.Context, &ChannelImportData{
 		Team:        &teamName,
 		Name:        &channelName,
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 	}, false)
 	_, appErr = th.App.GetChannelByName(channelName, team.Id, false)
 	require.Nil(t, appErr, "Failed to get channel from database.")
@@ -4195,11 +4201,12 @@ func TestZippedImportPostAndRepliesWithAttachments(t *testing.T) {
 
 	// Create a Channel.
 	channelName := model.NewId()
+	chanTypeOpen := model.ChannelTypeOpen
 	th.App.importChannel(th.Context, &ChannelImportData{
 		Team:        &teamName,
 		Name:        &channelName,
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 	}, false)
 	_, appErr = th.App.GetChannelByName(channelName, team.Id, false)
 	require.Nil(t, appErr, "Failed to get channel from database.")

app/import_test.go

@@ -70,7 +70,7 @@ func AssertAllPostsCount(t *testing.T, a *App, initialCount int64, change int64,
 	require.Equal(t, initialCount+change, result, "Did not find the expected number of posts.")
 }
 
-func AssertChannelCount(t *testing.T, a *App, channelType string, expectedCount int64) {
+func AssertChannelCount(t *testing.T, a *App, channelType model.ChannelType, expectedCount int64) {
 	count, err := a.Srv().Store.Channel().AnalyticsTypeCount("", channelType)
 	require.Equalf(t, expectedCount, count, "Channel count of type: %v. Expected: %v, Got: %v", channelType, expectedCount, count)
 	require.NoError(t, err, "Failed to get channel count.")

app/import_types.go

@@ -34,13 +34,13 @@ type TeamImportData struct {
 }
 
 type ChannelImportData struct {
-	Team        *string `json:"team"`
+	Team        *string            `json:"team"`
-	Name        *string `json:"name"`
+	Name        *string            `json:"name"`
-	DisplayName *string `json:"display_name"`
+	DisplayName *string            `json:"display_name"`
-	Type        *string `json:"type"`
+	Type        *model.ChannelType `json:"type"`
-	Header      *string `json:"header,omitempty"`
+	Header      *string            `json:"header,omitempty"`
-	Purpose     *string `json:"purpose,omitempty"`
+	Purpose     *string            `json:"purpose,omitempty"`
-	Scheme      *string `json:"scheme,omitempty"`
+	Scheme      *string            `json:"scheme,omitempty"`
 }
 
 type UserImportData struct {

app/import_validators_test.go

@@ -357,11 +357,12 @@ func TestImportValidateTeamImportData(t *testing.T) {
 func TestImportValidateChannelImportData(t *testing.T) {
 
 	// Test with minimum required valid properties.
+	chanTypeOpen := model.ChannelTypeOpen
 	data := ChannelImportData{
 		Team:        ptrStr("teamname"),
 		Name:        ptrStr("channelname"),
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 	}
 	err := validateChannelImportData(&data)
 	require.Nil(t, err, "Validation failed but should have been valid.")
@@ -370,7 +371,7 @@ func TestImportValidateChannelImportData(t *testing.T) {
 	data = ChannelImportData{
 		Name:        ptrStr("channelname"),
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 	}
 	err = validateChannelImportData(&data)
 	require.NotNil(t, err, "Should have failed due to missing team.")
@@ -379,7 +380,7 @@ func TestImportValidateChannelImportData(t *testing.T) {
 	data = ChannelImportData{
 		Team:        ptrStr("teamname"),
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 	}
 	err = validateChannelImportData(&data)
 	require.NotNil(t, err, "Should have failed due to missing name.")
@@ -400,7 +401,7 @@ func TestImportValidateChannelImportData(t *testing.T) {
 	data = ChannelImportData{
 		Team: ptrStr("teamname"),
 		Name: ptrStr("channelname"),
-		Type: ptrStr("O"),
+		Type: &chanTypeOpen,
 	}
 	err = validateChannelImportData(&data)
 	require.NotNil(t, err, "Should have failed due to missing display_name.")
@@ -422,11 +423,13 @@ func TestImportValidateChannelImportData(t *testing.T) {
 	err = validateChannelImportData(&data)
 	require.NotNil(t, err, "Should have failed due to missing type.")
 
-	data.Type = ptrStr("A")
+	invalidType := model.ChannelType("A")
+	data.Type = &invalidType
 	err = validateChannelImportData(&data)
 	require.NotNil(t, err, "Should have failed due to invalid type.")
 
-	data.Type = ptrStr("P")
+	chanTypePr := model.ChannelTypePrivate
+	data.Type = &chanTypePr
 	err = validateChannelImportData(&data)
 	require.Nil(t, err, "Should have succeeded with valid type.")
 
@@ -435,7 +438,7 @@ func TestImportValidateChannelImportData(t *testing.T) {
 		Team:        ptrStr("teamname"),
 		Name:        ptrStr("channelname"),
 		DisplayName: ptrStr("Display Name"),
-		Type:        ptrStr("O"),
+		Type:        &chanTypeOpen,
 		Header:      ptrStr("Channel Header Here"),
 		Purpose:     ptrStr("Channel Purpose Here"),
 	}

app/notification_push.go

@@ -161,7 +161,7 @@ func (a *App) sendPushNotification(notification *PostNotification, user *model.U
 }
 
 func (a *App) getPushNotificationMessage(contentsConfig, postMessage string, explicitMention, channelWideMention,
-	hasFiles bool, senderName, channelType, replyToThreadType string, userLocale i18n.TranslateFunc) string {
+	hasFiles bool, senderName string, channelType model.ChannelType, replyToThreadType string, userLocale i18n.TranslateFunc) string {
 
 	// If the post only has images then push an appropriate message
 	if postMessage == "" && hasFiles {

app/notification_push_test.go

@@ -573,7 +573,7 @@ func TestGetPushNotificationMessage(t *testing.T) {
 		replyToThreadType        string
 		Locale                   string
 		PushNotificationContents string
-		ChannelType              string
+		ChannelType              model.ChannelType
 
 		ExpectedMessage string
 	}{

app/slashcommands/auto_channels.go

@@ -19,7 +19,7 @@ type AutoChannelCreator struct {
 	DisplayNameCharset string
 	NameLen            utils.Range
 	NameCharset        string
-	ChannelType        string
+	ChannelType        model.ChannelType
 }
 
 func NewAutoChannelCreator(a *app.App, team *model.Team, userID string) *AutoChannelCreator {

app/slashcommands/helper_test.go

@@ -247,7 +247,7 @@ func (th *TestHelper) createPrivateChannel(team *model.Team) *model.Channel {
 	return th.createChannel(team, model.ChannelTypePrivate)
 }
 
-func (th *TestHelper) createChannel(team *model.Team, channelType string, options ...ChannelOption) *model.Channel {
+func (th *TestHelper) createChannel(team *model.Team, channelType model.ChannelType, options ...ChannelOption) *model.Channel {
 	id := model.NewId()
 
 	channel := &model.Channel{
@@ -288,7 +288,7 @@ func (th *TestHelper) createChannel(team *model.Team, channelType string, option
 	return channel
 }
 
-func (th *TestHelper) createChannelWithAnotherUser(team *model.Team, channelType, userID string) *model.Channel {
+func (th *TestHelper) createChannelWithAnotherUser(team *model.Team, channelType model.ChannelType, userID string) *model.Channel {
 	id := model.NewId()
 
 	channel := &model.Channel{

cmd/mattermost/commands/sampledata.go

@@ -617,9 +617,9 @@ func createChannel(idx int, teamName string) app.LineImportData {
 		purpose = purpose[0:250]
 	}
 
-	channelType := "P"
+	channelType := model.ChannelTypePrivate
 	if rand.Intn(2) == 0 {
-		channelType = "O"
+		channelType = model.ChannelTypeOpen
 	}
 
 	channel := app.ChannelImportData{

migrations/helper_test.go

@@ -159,7 +159,7 @@ func (th *TestHelper) CreateChannel(team *model.Team) *model.Channel {
 	return th.createChannel(team, model.ChannelTypeOpen)
 }
 
-func (th *TestHelper) createChannel(team *model.Team, channelType string) *model.Channel {
+func (th *TestHelper) createChannel(team *model.Team, channelType model.ChannelType) *model.Channel {
 	id := model.NewId()
 
 	channel := &model.Channel{

model/auditconv.go

@@ -60,7 +60,7 @@ func AuditModelTypeConv(val interface{}) (newVal interface{}, converted bool) {
 type auditChannel struct {
 	ID   string
 	Name string
-	Type string
+	Type ChannelType
 }
 
 // newAuditChannel creates a simplified representation of Channel for output to audit log.
@@ -77,7 +77,7 @@ func newAuditChannel(c *Channel) auditChannel {
 func (c auditChannel) MarshalJSONObject(enc *gojay.Encoder) {
 	enc.StringKey("id", c.ID)
 	enc.StringKey("name", c.Name)
-	enc.StringKey("type", c.Type)
+	enc.StringKey("type", string(c.Type))
 }
 
 func (c auditChannel) IsNil() bool {

model/channel.go

@@ -14,11 +14,13 @@ import (
 	"unicode/utf8"
 )
 
+type ChannelType string
+
 const (
-	ChannelTypeOpen    = "O"
+	ChannelTypeOpen    ChannelType = "O"
-	ChannelTypePrivate = "P"
+	ChannelTypePrivate ChannelType = "P"
-	ChannelTypeDirect  = "D"
+	ChannelTypeDirect  ChannelType = "D"
-	ChannelTypeGroup   = "G"
+	ChannelTypeGroup   ChannelType = "G"
 
 	ChannelGroupMaxUsers       = 8
 	ChannelGroupMinUsers       = 3
@@ -40,7 +42,7 @@ type Channel struct {
 	UpdateAt          int64                  `json:"update_at"`
 	DeleteAt          int64                  `json:"delete_at"`
 	TeamId            string                 `json:"team_id"`
-	Type              string                 `json:"type"`
+	Type              ChannelType            `json:"type"`
 	DisplayName       string                 `json:"display_name"`
 	Name              string                 `json:"name"`
 	Header            string                 `json:"header"`

model/client4.go

@@ -2453,8 +2453,8 @@ func (c *Client4) ConvertChannelToPrivate(channelId string) (*Channel, *Response
 }
 
 // UpdateChannelPrivacy updates channel privacy
-func (c *Client4) UpdateChannelPrivacy(channelId string, privacy string) (*Channel, *Response) {
+func (c *Client4) UpdateChannelPrivacy(channelId string, privacy ChannelType) (*Channel, *Response) {
-	requestBody := map[string]string{"privacy": privacy}
+	requestBody := map[string]string{"privacy": string(privacy)}
 	r, err := c.DoApiPut(c.GetChannelRoute(channelId)+"/privacy", MapToJson(requestBody))
 	if err != nil {
 		return nil, BuildErrorResponse(r, err)

model/message_export.go

@@ -11,7 +11,7 @@ type MessageExport struct {
 	ChannelId          *string
 	ChannelName        *string
 	ChannelDisplayName *string
-	ChannelType        *string
+	ChannelType        *ChannelType
 
 	UserId    *string
 	UserEmail *string

model/role.go

@@ -554,7 +554,7 @@ func ChannelModeratedPermissionsChangedByPatch(role *Role, patch *RolePatch) []s
 }
 
 // GetChannelModeratedPermissions returns a map of channel moderated permissions that the role has access to
-func (r *Role) GetChannelModeratedPermissions(channelType string) map[string]bool {
+func (r *Role) GetChannelModeratedPermissions(channelType ChannelType) map[string]bool {
 	moderatedPermissions := make(map[string]bool)
 	for _, permission := range r.Permissions {
 		if _, found := ChannelModeratedPermissionsMap[permission]; !found {

model/role_test.go

@@ -231,7 +231,7 @@ func TestGetChannelModeratedPermissions(t *testing.T) {
 	tests := []struct {
 		Name        string
 		Permissions []string
-		ChannelType string
+		ChannelType ChannelType
 		Expected    map[string]bool
 	}{
 		{

model/shared_channel.go

@@ -16,19 +16,19 @@ import (
 // If "home" is false, then the shared channel is homed remotely, and "RemoteId"
 // field points to the remote cluster connection in "RemoteClusters" table.
 type SharedChannel struct {
-	ChannelId        string `json:"id"`
+	ChannelId        string      `json:"id"`
-	TeamId           string `json:"team_id"`
+	TeamId           string      `json:"team_id"`
-	Home             bool   `json:"home"`
+	Home             bool        `json:"home"`
-	ReadOnly         bool   `json:"readonly"`
+	ReadOnly         bool        `json:"readonly"`
-	ShareName        string `json:"name"`
+	ShareName        string      `json:"name"`
-	ShareDisplayName string `json:"display_name"`
+	ShareDisplayName string      `json:"display_name"`
-	SharePurpose     string `json:"purpose"`
+	SharePurpose     string      `json:"purpose"`
-	ShareHeader      string `json:"header"`
+	ShareHeader      string      `json:"header"`
-	CreatorId        string `json:"creator_id"`
+	CreatorId        string      `json:"creator_id"`
-	CreateAt         int64  `json:"create_at"`
+	CreateAt         int64       `json:"create_at"`
-	UpdateAt         int64  `json:"update_at"`
+	UpdateAt         int64       `json:"update_at"`
-	RemoteId         string `json:"remote_id,omitempty"` // if not "home"
+	RemoteId         string      `json:"remote_id,omitempty"` // if not "home"
-	Type             string `db:"-"`
+	Type             ChannelType `db:"-"`
 }
 
 func (sc *SharedChannel) ToJson() string {

services/sharedchannel/channelinvite.go

@@ -17,15 +17,15 @@ import (
 
 // channelInviteMsg represents an invitation for a remote cluster to start sharing a channel.
 type channelInviteMsg struct {
-	ChannelId            string   `json:"channel_id"`
+	ChannelId            string            `json:"channel_id"`
-	TeamId               string   `json:"team_id"`
+	TeamId               string            `json:"team_id"`
-	ReadOnly             bool     `json:"read_only"`
+	ReadOnly             bool              `json:"read_only"`
-	Name                 string   `json:"name"`
+	Name                 string            `json:"name"`
-	DisplayName          string   `json:"display_name"`
+	DisplayName          string            `json:"display_name"`
-	Header               string   `json:"header"`
+	Header               string            `json:"header"`
-	Purpose              string   `json:"purpose"`
+	Purpose              string            `json:"purpose"`
-	Type                 string   `json:"type"`
+	Type                 model.ChannelType `json:"type"`
-	DirectParticipantIDs []string `json:"direct_participant_ids"`
+	DirectParticipantIDs []string          `json:"direct_participant_ids"`
 }
 
 type InviteOption func(msg *channelInviteMsg)

services/slackimport/parsers.go

@@ -7,10 +7,11 @@ import (
 	"encoding/json"
 	"io"
 
+	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/shared/mlog"
 )
 
-func slackParseChannels(data io.Reader, channelType string) ([]slackChannel, error) {
+func slackParseChannels(data io.Reader, channelType model.ChannelType) ([]slackChannel, error) {
 	decoder := json.NewDecoder(data)
 
 	var channels []slackChannel

services/slackimport/slackimport.go

@@ -31,7 +31,7 @@ type slackChannel struct {
 	Members []string        `json:"members"`
 	Purpose slackChannelSub `json:"purpose"`
 	Topic   slackChannelSub `json:"topic"`
-	Type    string
+	Type    model.ChannelType
 }
 
 type slackChannelSub struct {

services/telemetry/telemetry_test.go

@@ -101,9 +101,9 @@ func initializeMocks(cfg *model.Config) (*mocks.ServerIface, *storeMocks.Store,
 	teamStore.On("GroupSyncedTeamCount").Return(int64(16), nil)
 
 	channelStore := storeMocks.ChannelStore{}
-	channelStore.On("AnalyticsTypeCount", "", "O").Return(int64(25), nil)
+	channelStore.On("AnalyticsTypeCount", "", model.ChannelTypeOpen).Return(int64(25), nil)
-	channelStore.On("AnalyticsTypeCount", "", "P").Return(int64(26), nil)
+	channelStore.On("AnalyticsTypeCount", "", model.ChannelTypePrivate).Return(int64(26), nil)
-	channelStore.On("AnalyticsTypeCount", "", "D").Return(int64(27), nil)
+	channelStore.On("AnalyticsTypeCount", "", model.ChannelTypeDirect).Return(int64(27), nil)
 	channelStore.On("AnalyticsDeletedTypeCount", "", "O").Return(int64(22), nil)
 	channelStore.On("AnalyticsDeletedTypeCount", "", "P").Return(int64(23), nil)
 	channelStore.On("GroupSyncedChannelCount").Return(int64(17), nil)

store/opentracinglayer/opentracinglayer.go

@@ -552,7 +552,7 @@ func (s *OpenTracingLayerChannelStore) AnalyticsDeletedTypeCount(teamID string,
 	return result, err
 }
 
-func (s *OpenTracingLayerChannelStore) AnalyticsTypeCount(teamID string, channelType string) (int64, error) {
+func (s *OpenTracingLayerChannelStore) AnalyticsTypeCount(teamID string, channelType model.ChannelType) (int64, error) {
 	origCtx := s.Root.Store.Context()
 	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ChannelStore.AnalyticsTypeCount")
 	s.Root.Store.SetContext(newCtx)

store/retrylayer/retrylayer.go

@@ -588,7 +588,7 @@ func (s *RetryLayerChannelStore) AnalyticsDeletedTypeCount(teamID string, channe
 
 }
 
-func (s *RetryLayerChannelStore) AnalyticsTypeCount(teamID string, channelType string) (int64, error) {
+func (s *RetryLayerChannelStore) AnalyticsTypeCount(teamID string, channelType model.ChannelType) (int64, error) {
 
 	tries := 0
 	for {

store/searchtest/helper.go

@@ -239,7 +239,7 @@ func (th *SearchTestHelper) deleteBot(botID string) error {
 	return nil
 }
 
-func (th *SearchTestHelper) createChannel(teamID, name, displayName, purpose, channelType string, deleted bool) (*model.Channel, error) {
+func (th *SearchTestHelper) createChannel(teamID, name, displayName, purpose string, channelType model.ChannelType, deleted bool) (*model.Channel, error) {
 	channel, err := th.Store.Channel().Save(&model.Channel{
 		TeamId:      teamID,
 		DisplayName: displayName,

store/sqlstore/channel_store.go

@@ -1043,7 +1043,7 @@ func (s SqlChannelStore) getAllChannelsQuery(opts store.ChannelSearchOpts, forCo
 	query := s.getQueryBuilder().
 		Select(selectStr).
 		From("Channels AS c").
-		Where(sq.Eq{"c.Type": []string{model.ChannelTypePrivate, model.ChannelTypeOpen}})
+		Where(sq.Eq{"c.Type": []model.ChannelType{model.ChannelTypePrivate, model.ChannelTypeOpen}})
 
 	if !forCount {
 		query = query.Join("Teams ON Teams.Id = c.TeamId")
@@ -2376,7 +2376,7 @@ func (s SqlChannelStore) GetForPost(postId string) (*model.Channel, error) {
 	return channel, nil
 }
 
-func (s SqlChannelStore) AnalyticsTypeCount(teamId string, channelType string) (int64, error) {
+func (s SqlChannelStore) AnalyticsTypeCount(teamId string, channelType model.ChannelType) (int64, error) {
 	query := "SELECT COUNT(Id) AS Value FROM Channels WHERE Type = :ChannelType"
 
 	if teamId != "" {

store/sqlstore/channel_store_categories.go

@@ -378,11 +378,11 @@ func (s SqlChannelStore) completePopulatingCategoryChannelsT(db dbSelecter, cate
 	var channelTypeFilter sq.Sqlizer
 	if category.Type == model.SidebarCategoryDirectMessages {
 		// any DM/GM channels that aren't in any category should be returned as part of the Direct Messages category
-		channelTypeFilter = sq.Eq{"Channels.Type": []string{model.ChannelTypeDirect, model.ChannelTypeGroup}}
+		channelTypeFilter = sq.Eq{"Channels.Type": []model.ChannelType{model.ChannelTypeDirect, model.ChannelTypeGroup}}
 	} else if category.Type == model.SidebarCategoryChannels {
 		// any public/private channels that are on the current team and aren't in any category should be returned as part of the Channels category
 		channelTypeFilter = sq.And{
-			sq.Eq{"Channels.Type": []string{model.ChannelTypeOpen, model.ChannelTypePrivate}},
+			sq.Eq{"Channels.Type": []model.ChannelType{model.ChannelTypeOpen, model.ChannelTypePrivate}},
 			sq.Eq{"Channels.TeamId": category.TeamId},
 		}
 	}

store/sqlstore/integrity.go

@@ -215,7 +215,7 @@ func checkTeamsChannelsIntegrity(ss *SqlStore) model.IntegrityCheckResult {
 		parentIdAttr: "TeamId",
 		childName:    "Channels",
 		childIdAttr:  "Id",
-		filter:       sq.NotEq{"CT.Type": []string{model.ChannelTypeDirect, model.ChannelTypeGroup}},
+		filter:       sq.NotEq{"CT.Type": []model.ChannelType{model.ChannelTypeDirect, model.ChannelTypeGroup}},
 	})
 	res2 := checkParentChildIntegrity(ss, relationalCheckConfig{
 		parentName:         "Teams",
@@ -223,7 +223,7 @@ func checkTeamsChannelsIntegrity(ss *SqlStore) model.IntegrityCheckResult {
 		childName:          "Channels",
 		childIdAttr:        "Id",
 		canParentIdBeEmpty: true,
-		filter:             sq.Eq{"CT.Type": []string{model.ChannelTypeDirect, model.ChannelTypeGroup}},
+		filter:             sq.Eq{"CT.Type": []model.ChannelType{model.ChannelTypeDirect, model.ChannelTypeGroup}},
 	})
 	data1 := res1.Data.(model.RelationalIntegrityCheckData)
 	data2 := res2.Data.(model.RelationalIntegrityCheckData)

store/store.go

@@ -220,7 +220,7 @@ type ChannelStore interface {
 	UpdateLastViewedAtPost(unreadPost *model.Post, userID string, mentionCount, mentionCountRoot int, updateThreads bool, setUnreadCountRoot bool) (*model.ChannelUnreadAt, error)
 	CountPostsAfter(channelID string, timestamp int64, userID string) (int, int, error)
 	IncrementMentionCount(channelID string, userID string, updateThreads, isRoot bool) error
-	AnalyticsTypeCount(teamID string, channelType string) (int64, error)
+	AnalyticsTypeCount(teamID string, channelType model.ChannelType) (int64, error)
 	GetMembersForUser(teamID string, userID string) (*model.ChannelMembers, error)
 	GetMembersForUserWithPagination(teamID, userID string, page, perPage int) (*model.ChannelMembers, error)
 	AutocompleteInTeam(teamID string, term string, includeDeleted bool) (*model.ChannelList, error)

store/storetest/group_store.go

@@ -3942,7 +3942,7 @@ func groupTestAdminRoleGroupsForSyncableMemberTeam(t *testing.T, ss store.Store)
 	team := &model.Team{
 		DisplayName: "A Name",
 		Name:        "zz" + model.NewId(),
-		Type:        model.ChannelTypeOpen,
+		Type:        model.TeamOpen,
 	}
 	team, nErr := ss.Team().Save(team)
 	require.NoError(t, nErr)
@@ -4045,7 +4045,7 @@ func groupTestPermittedSyncableAdminsTeam(t *testing.T, ss store.Store) {
 	team := &model.Team{
 		DisplayName: "A Name",
 		Name:        "zz" + model.NewId(),
-		Type:        model.ChannelTypeOpen,
+		Type:        model.TeamOpen,
 	}
 	team, nErr := ss.Team().Save(team)
 	require.NoError(t, nErr)

store/storetest/mocks/ChannelStore.go

@@ -40,18 +40,18 @@ func (_m *ChannelStore) AnalyticsDeletedTypeCount(teamID string, channelType str
 }
 
 // AnalyticsTypeCount provides a mock function with given fields: teamID, channelType
-func (_m *ChannelStore) AnalyticsTypeCount(teamID string, channelType string) (int64, error) {
+func (_m *ChannelStore) AnalyticsTypeCount(teamID string, channelType model.ChannelType) (int64, error) {
 	ret := _m.Called(teamID, channelType)
 
 	var r0 int64
-	if rf, ok := ret.Get(0).(func(string, string) int64); ok {
+	if rf, ok := ret.Get(0).(func(string, model.ChannelType) int64); ok {
 		r0 = rf(teamID, channelType)
 	} else {
 		r0 = ret.Get(0).(int64)
 	}
 
 	var r1 error
-	if rf, ok := ret.Get(1).(func(string, string) error); ok {
+	if rf, ok := ret.Get(1).(func(string, model.ChannelType) error); ok {
 		r1 = rf(teamID, channelType)
 	} else {
 		r1 = ret.Error(1)

store/timerlayer/timerlayer.go

@@ -534,7 +534,7 @@ func (s *TimerLayerChannelStore) AnalyticsDeletedTypeCount(teamID string, channe
 	return result, err
 }
 
-func (s *TimerLayerChannelStore) AnalyticsTypeCount(teamID string, channelType string) (int64, error) {
+func (s *TimerLayerChannelStore) AnalyticsTypeCount(teamID string, channelType model.ChannelType) (int64, error) {
 	start := timemodule.Now()
 
 	result, err := s.ChannelStore.AnalyticsTypeCount(teamID, channelType)