MM-24135: Migrate AppError from SaveChannel/channel_store.go (#14299)

* MM-24135: Migrate AppError from SaveChannel/channel_store.go

This is the first POC of migration of store app errors to plain error.

We create a few basic error types in the store package and use
them to return the errors from store methods. In the app layer,
we inspect the error and re-create the exact app errors. This lets
us preserve the same error content, but yet move to plain errors.

Since this is a gradual migration, this means that the error inspection
code will be duplicated across the app layer whenever a store method
is invoked. But all of that should go away once we start propagating
the errors higher up the hierarchy.

There have been a significant amount of changes in the storetest and searchtest
layer, primarily because we have to rename the err variable now that it is of
a different type.

* Addressed review comments

* Made all appError origins to be CreateChannel

* Remove typed internal error

* Fix translations

* fix layer generation

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

api4/scheme_test.go

@@ -424,8 +424,8 @@ func TestGetChannelsForScheme(t *testing.T) {
 		Type:        model.CHANNEL_OPEN,
 		SchemeId:    &scheme1.Id,
 	}
-	channel2, err = th.App.Srv().Store.Channel().Save(channel2, 1000000)
+	channel2, nErr := th.App.Srv().Store.Channel().Save(channel2, 1000000)
-	assert.Nil(t, err)
+	assert.Nil(t, nErr)
 
 	l4, r4 := th.SystemAdminClient.GetChannelsForScheme(scheme1.Id, 0, 100)
 	CheckNoError(t, r4)

app/channel.go

@@ -4,6 +4,7 @@
 package app
 
 import (
+	"errors"
 	"fmt"
 	"net/http"
 	"strings"
@@ -205,10 +206,31 @@ func (a *App) RenameChannel(channel *model.Channel, newChannelName string, newDi
 
 func (a *App) CreateChannel(channel *model.Channel, addMember bool) (*model.Channel, *model.AppError) {
 	channel.DisplayName = strings.TrimSpace(channel.DisplayName)
-
+	sc, nErr := a.Srv().Store.Channel().Save(channel, *a.Config().TeamSettings.MaxChannelsPerTeam)
-	sc, err := a.Srv().Store.Channel().Save(channel, *a.Config().TeamSettings.MaxChannelsPerTeam)
+	if nErr != nil {
-	if err != nil {
+		var invErr *store.ErrInvalidInput
-		return nil, err
+		var cErr *store.ErrConflict
+		var ltErr *store.ErrLimitExceeded
+		var appErr *model.AppError
+		switch {
+		case errors.As(nErr, &invErr):
+			switch {
+			case invErr.Entity == "Channel" && invErr.Field == "DeleteAt":
+				return nil, model.NewAppError("CreateChannel", "store.sql_channel.save.archived_channel.app_error", nil, "", http.StatusBadRequest)
+			case invErr.Entity == "Channel" && invErr.Field == "Type":
+				return nil, model.NewAppError("CreateChannel", "store.sql_channel.save.direct_channel.app_error", nil, "", http.StatusBadRequest)
+			case invErr.Entity == "Channel" && invErr.Field == "Id":
+				return nil, model.NewAppError("CreateChannel", "store.sql_channel.save_channel.existing.app_error", nil, "id="+invErr.Value.(string), http.StatusBadRequest)
+			}
+		case errors.As(nErr, &cErr):
+			return channel, model.NewAppError("CreateChannel", store.CHANNEL_EXISTS_ERROR, nil, cErr.Error(), http.StatusBadRequest)
+		case errors.As(nErr, &ltErr):
+			return nil, model.NewAppError("CreateChannel", "store.sql_channel.save_channel.limit.app_error", nil, ltErr.Error(), http.StatusBadRequest)
+		case errors.As(nErr, &appErr): // in case we haven't converted to plain error.
+			return nil, appErr
+		default: // last fallback in case it doesn't map to an existing app error.
+			return nil, model.NewAppError("CreateChannel", "app.channel.create_channel.internal_error", nil, nErr.Error(), http.StatusInternalServerError)
+		}
 	}
 
 	if addMember {
@@ -407,12 +429,31 @@ func (a *App) createGroupChannel(userIds []string, creatorId string) (*model.Cha
 		Type:        model.CHANNEL_GROUP,
 	}
 
-	channel, err := a.Srv().Store.Channel().Save(group, *a.Config().TeamSettings.MaxChannelsPerTeam)
+	channel, nErr := a.Srv().Store.Channel().Save(group, *a.Config().TeamSettings.MaxChannelsPerTeam)
-	if err != nil {
+	if nErr != nil {
-		if err.Id == store.CHANNEL_EXISTS_ERROR {
+		var invErr *store.ErrInvalidInput
-			return channel, err
+		var cErr *store.ErrConflict
+		var ltErr *store.ErrLimitExceeded
+		var appErr *model.AppError
+		switch {
+		case errors.As(nErr, &invErr):
+			switch {
+			case invErr.Entity == "Channel" && invErr.Field == "DeleteAt":
+				return nil, model.NewAppError("CreateChannel", "store.sql_channel.save.archived_channel.app_error", nil, "", http.StatusBadRequest)
+			case invErr.Entity == "Channel" && invErr.Field == "Type":
+				return nil, model.NewAppError("CreateChannel", "store.sql_channel.save.direct_channel.app_error", nil, "", http.StatusBadRequest)
+			case invErr.Entity == "Channel" && invErr.Field == "Id":
+				return nil, model.NewAppError("CreateChannel", "store.sql_channel.save_channel.existing.app_error", nil, "id="+invErr.Value.(string), http.StatusBadRequest)
+			}
+		case errors.As(nErr, &cErr):
+			return channel, model.NewAppError("CreateChannel", store.CHANNEL_EXISTS_ERROR, nil, cErr.Error(), http.StatusBadRequest)
+		case errors.As(nErr, &ltErr):
+			return nil, model.NewAppError("CreateChannel", "store.sql_channel.save_channel.limit.app_error", nil, ltErr.Error(), http.StatusBadRequest)
+		case errors.As(nErr, &appErr): // in case we haven't converted to plain error.
+			return nil, appErr
+		default: // last fallback in case it doesn't map to an existing app error.
+			return nil, model.NewAppError("CreateChannel", "app.channel.create_channel.internal_error", nil, nErr.Error(), http.StatusInternalServerError)
 		}
-		return nil, err
 	}
 
 	for _, user := range users {

i18n/en.json

@@ -2930,6 +2930,10 @@
     "id": "app.bot.get_disable_bot_sysadmin_message",
     "translation": "{{if .disableBotsSetting}}{{if .printAllBots}}{{.UserName}} was deactivated. They managed the following bot accounts which have now been disabled.\n\n{{.BotNames}}{{else}}{{.UserName}} was deactivated. They managed {{.NumBots}} bot accounts which have now been disabled, including the following:\n\n{{.BotNames}}{{end}}You can take ownership of each bot by enabling it at **Integrations > Bot Accounts** and creating new tokens for the bot.\n\nFor more information, see our [documentation](https://docs.mattermost.com/developer/bot-accounts.html#what-happens-when-a-user-who-owns-bot-accounts-is-disabled).{{else}}{{if .printAllBots}}{{.UserName}} was deactivated. They managed the following bot accounts which are still enabled.\n\n{{.BotNames}}\n{{else}}{{.UserName}} was deactivated. They managed {{.NumBots}} bot accounts which are still enabled, including the following:\n\n{{.BotNames}}{{end}}We strongly recommend you to take ownership of each bot by re-enabling it at **Integrations > Bot Accounts** and creating new tokens for the bot.\n\nFor more information, see our [documentation](https://docs.mattermost.com/developer/bot-accounts.html#what-happens-when-a-user-who-owns-bot-accounts-is-disabled).\n\nIf you want bot accounts to disable automatically after owner deactivation, set “Disable bot accounts when owner is deactivated” in **System Console > Integrations > Bot Accounts** to true.{{end}}"
   },
+  {
+    "id": "app.channel.create_channel.internal_error",
+    "translation": "Unable to save channel."
+  },
   {
     "id": "app.channel.create_channel.no_team_id.app_error",
     "translation": "Must specify the team ID to create a channel."
@@ -6042,26 +6046,10 @@
     "id": "store.sql_channel.save.archived_channel.app_error",
     "translation": "You can not modify an archived channel."
   },
-  {
-    "id": "store.sql_channel.save.commit_transaction.app_error",
-    "translation": "Unable to commit transaction."
-  },
   {
     "id": "store.sql_channel.save.direct_channel.app_error",
     "translation": "Use SaveDirectChannel to create a direct channel."
   },
-  {
-    "id": "store.sql_channel.save.open_transaction.app_error",
-    "translation": "Unable to open transaction."
-  },
-  {
-    "id": "store.sql_channel.save.upsert_public_channel.app_error",
-    "translation": "Unable to upsert materialized public channel."
-  },
-  {
-    "id": "store.sql_channel.save_channel.current_count.app_error",
-    "translation": "Failed to get current channel count."
-  },
   {
     "id": "store.sql_channel.save_channel.existing.app_error",
     "translation": "Must call update for existing channel."
@@ -6074,10 +6062,6 @@
     "id": "store.sql_channel.save_channel.limit.app_error",
     "translation": "You've reached the limit of the number of allowed channels."
   },
-  {
-    "id": "store.sql_channel.save_channel.save.app_error",
-    "translation": "Unable to save the channel."
-  },
   {
     "id": "store.sql_channel.save_direct_channel.add_members.app_error",
     "translation": "Unable to add direct channel members."
@@ -6086,6 +6070,10 @@
     "id": "store.sql_channel.save_direct_channel.commit.app_error",
     "translation": "Unable to commit transaction."
   },
+  {
+    "id": "store.sql_channel.save_direct_channel.internal_error",
+    "translation": "Unable to save direct channel."
+  },
   {
     "id": "store.sql_channel.save_direct_channel.not_direct.app_error",
     "translation": "Not a direct channel attempted to be created with SaveDirectChannel."

store/errors.go

@@ -0,0 +1,73 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package store
+
+import (
+	"fmt"
+)
+
+// ErrInvalidInput indicates an error that has occured due to an invalid input.
+type ErrInvalidInput struct {
+	Entity string      // The entity which was sent as the input.
+	Field  string      // The field of the entity which was invalid.
+	Value  interface{} // The actual value of the field.
+}
+
+func NewErrInvalidInput(entity, field string, value interface{}) *ErrInvalidInput {
+	return &ErrInvalidInput{
+		Entity: entity,
+		Field:  field,
+		Value:  value,
+	}
+}
+
+func (e *ErrInvalidInput) Error() string {
+	return fmt.Sprintf("invalid input: entity: %s field: %s value: %s", e.Entity, e.Field, e.Value)
+}
+
+// ErrLimitExceeded indicates an error that has occured because some value exceeded a limit.
+type ErrLimitExceeded struct {
+	What  string // What was the object that exceeded.
+	Count int    // The value of the object.
+	meta  string // Any additional metadata.
+}
+
+func NewErrLimitExceeded(what string, count int, meta string) *ErrLimitExceeded {
+	return &ErrLimitExceeded{
+		What:  what,
+		Count: count,
+		meta:  meta,
+	}
+}
+
+func (e *ErrLimitExceeded) Error() string {
+	return fmt.Sprintf("limit exceeded: what: %s count: %d metadata: %s", e.What, e.Count, e.meta)
+}
+
+// ErrConflict indicates a conflict that occured.
+type ErrConflict struct {
+	Resource string // The resource which created the conflict.
+	err      error  // Internal error.
+	meta     string // Any additional metadata.
+}
+
+func NewErrConflict(resource string, err error, meta string) *ErrConflict {
+	return &ErrConflict{
+		Resource: resource,
+		err:      err,
+		meta:     meta,
+	}
+}
+
+func (e *ErrConflict) Error() string {
+	return e.Resource + "exists " + e.meta + " " + e.err.Error()
+}
+
+func (e *ErrConflict) Unwrap() error {
+	return e.err
+}
+
+// TODO:
+// type ErrNotFound struct {
+// }

store/opentracing_layer.go

@@ -1665,7 +1665,7 @@ func (s *OpenTracingLayerChannelStore) Restore(channelId string, time int64) *mo
 	return resultVar0
 }
 
-func (s *OpenTracingLayerChannelStore) Save(channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, *model.AppError) {
+func (s *OpenTracingLayerChannelStore) Save(channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, error) {
 	origCtx := s.Root.Store.Context()
 	span, newCtx := tracing.StartSpanWithParentByContext(s.Root.Store.Context(), "ChannelStore.Save")
 	s.Root.Store.SetContext(newCtx)

store/searchlayer/channel_layer.go

@@ -45,7 +45,7 @@ func (c *SearchChannelStore) indexChannel(channel *model.Channel) {
 	}
 }
 
-func (c *SearchChannelStore) Save(channel *model.Channel, maxChannels int64) (*model.Channel, *model.AppError) {
+func (c *SearchChannelStore) Save(channel *model.Channel, maxChannels int64) (*model.Channel, error) {
 	newChannel, err := c.ChannelStore.Save(channel, maxChannels)
 	if err == nil {
 		c.indexChannel(newChannel)

store/searchtest/channel_layer.go

@@ -113,6 +113,7 @@ func testAutocompleteChannelByNameSplittedWithUnderscoreChar(t *testing.T, th *S
 func testAutocompleteChannelByDisplayNameSplittedByWhitespaces(t *testing.T, th *SearchTestHelper) {
 	alternate, err := th.createChannel(th.Team.Id, "channel-alternate", "Channel Alternate", "", model.CHANNEL_OPEN, false)
 	require.Nil(t, err)
+
 	defer th.deleteChannel(alternate)
 	res, apperr := th.Store.Channel().AutocompleteInTeam(th.Team.Id, "Channel A", false)
 	require.Nil(t, apperr)

store/sqlstore/channel_store.go

@@ -502,35 +502,33 @@ func (s SqlChannelStore) upsertPublicChannelT(transaction *gorp.Transaction, cha
 }
 
 // Save writes the (non-direct) channel channel to the database.
-func (s SqlChannelStore) Save(channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, *model.AppError) {
+func (s SqlChannelStore) Save(channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, error) {
-
 	if channel.DeleteAt != 0 {
-		return nil, model.NewAppError("SqlChannelStore.Save", "store.sql_channel.save.archived_channel.app_error", nil, "", http.StatusBadRequest)
+		return nil, store.NewErrInvalidInput("Channel", "DeleteAt", channel.DeleteAt)
 	}
 
 	if channel.Type == model.CHANNEL_DIRECT {
-		return nil, model.NewAppError("SqlChannelStore.Save", "store.sql_channel.save.direct_channel.app_error", nil, "", http.StatusBadRequest)
+		return nil, store.NewErrInvalidInput("Channel", "Type", channel.Type)
 	}
 
 	transaction, err := s.GetMaster().Begin()
 	if err != nil {
-		return nil, model.NewAppError("SqlChannelStore.Save", "store.sql_channel.save.open_transaction.app_error", nil, err.Error(), http.StatusInternalServerError)
+		return nil, errors.Wrapf(err, "begin_transaction: ")
 	}
 	defer finalizeTransaction(transaction)
 
-	newChannel, appErr := s.saveChannelT(transaction, channel, maxChannelsPerTeam)
+	newChannel, err := s.saveChannelT(transaction, channel, maxChannelsPerTeam)
-	if appErr != nil {
+	if err != nil {
-		return newChannel, appErr
+		return newChannel, err
 	}
 
 	// Additionally propagate the write to the PublicChannels table.
 	if err := s.upsertPublicChannelT(transaction, newChannel); err != nil {
-		return nil, model.NewAppError("SqlChannelStore.Save", "store.sql_channel.save.upsert_public_channel.app_error", nil, err.Error(), http.StatusInternalServerError)
+		return nil, errors.Wrapf(err, "upsert_public_channel: ")
-
 	}
 
 	if err := transaction.Commit(); err != nil {
-		return nil, model.NewAppError("SqlChannelStore.Save", "store.sql_channel.save.commit_transaction.app_error", nil, err.Error(), http.StatusInternalServerError)
+		return nil, errors.Wrapf(err, "commit_transaction: ")
 	}
 
 	return newChannel, nil
@@ -577,9 +575,39 @@ func (s SqlChannelStore) SaveDirectChannel(directchannel *model.Channel, member1
 	defer finalizeTransaction(transaction)
 
 	directchannel.TeamId = ""
-	newChannel, appErr := s.saveChannelT(transaction, directchannel, 0)
+	newChannel, err := s.saveChannelT(transaction, directchannel, 0)
-	if appErr != nil {
+	if err != nil {
-		return newChannel, appErr
+		// TODO: This will go away once SaveDirectChannel returns error
+		var invErr *store.ErrInvalidInput
+		var cErr *store.ErrConflict
+		var ltErr *store.ErrLimitExceeded
+		var appErr *model.AppError
+		if errors.As(err, &invErr) {
+			if invErr.Entity == "Channel" && invErr.Field == "DeleteAt" {
+				return newChannel, model.NewAppError("CreateChannel", "store.sql_channel.save.archived_channel.app_error", nil, "", http.StatusBadRequest)
+			}
+			if invErr.Entity == "Channel" && invErr.Field == "Type" {
+				return newChannel, model.NewAppError("CreateChannel", "store.sql_channel.save.direct_channel.app_error", nil, "", http.StatusBadRequest)
+			}
+			if invErr.Entity == "Channel" && invErr.Field == "Id" {
+				return newChannel, model.NewAppError("SqlChannelStore.Save", "store.sql_channel.save_channel.existing.app_error", nil, "id="+invErr.Value.(string), http.StatusBadRequest)
+			}
+		}
+		if errors.As(err, &cErr) {
+			if cErr.Resource == "Channel" {
+				return newChannel, model.NewAppError("CreateChannel", store.CHANNEL_EXISTS_ERROR, nil, cErr.Error(), http.StatusBadRequest)
+			}
+		}
+		if errors.As(err, &ltErr) {
+			if ltErr.What == "channels_per_team" {
+				return newChannel, model.NewAppError("CreateChannel", "store.sql_channel.save_channel.limit.app_error", nil, ltErr.Error(), http.StatusBadRequest)
+			}
+		}
+		if errors.As(err, &appErr) {
+			return nil, appErr
+		} else {
+			return nil, model.NewAppError("SqlChannelStore.SaveDirectChannel", "store.sql_channel.save_direct_channel.internal_error", nil, err.Error(), http.StatusInternalServerError)
+		}
 	}
 
 	// Members need new channel ID
@@ -605,21 +633,21 @@ func (s SqlChannelStore) SaveDirectChannel(directchannel *model.Channel, member1
 
 }
 
-func (s SqlChannelStore) saveChannelT(transaction *gorp.Transaction, channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, *model.AppError) {
+func (s SqlChannelStore) saveChannelT(transaction *gorp.Transaction, channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, error) {
 	if len(channel.Id) > 0 {
-		return nil, model.NewAppError("SqlChannelStore.Save", "store.sql_channel.save_channel.existing.app_error", nil, "id="+channel.Id, http.StatusBadRequest)
+		return nil, store.NewErrInvalidInput("Channel", "Id", channel.Id)
 	}
 
 	channel.PreSave()
-	if err := channel.IsValid(); err != nil {
+	if err := channel.IsValid(); err != nil { // TODO: this needs to return plain error
-		return nil, err
+		return nil, err // we just pass through the error as-is for now.
 	}
 
 	if channel.Type != model.CHANNEL_DIRECT && channel.Type != model.CHANNEL_GROUP && maxChannelsPerTeam >= 0 {
 		if count, err := transaction.SelectInt("SELECT COUNT(0) FROM Channels WHERE TeamId = :TeamId AND DeleteAt = 0 AND (Type = 'O' OR Type = 'P')", map[string]interface{}{"TeamId": channel.TeamId}); err != nil {
-			return nil, model.NewAppError("SqlChannelStore.Save", "store.sql_channel.save_channel.current_count.app_error", nil, "teamId="+channel.TeamId+", "+err.Error(), http.StatusInternalServerError)
+			return nil, errors.Wrapf(err, "save_channel_count: teamId=%s", channel.TeamId)
 		} else if count >= maxChannelsPerTeam {
-			return nil, model.NewAppError("SqlChannelStore.Save", "store.sql_channel.save_channel.limit.app_error", nil, "teamId="+channel.TeamId, http.StatusBadRequest)
+			return nil, store.NewErrLimitExceeded("channels_per_team", int(count), "teamId="+channel.TeamId)
 		}
 	}
 
@@ -627,9 +655,9 @@ func (s SqlChannelStore) saveChannelT(transaction *gorp.Transaction, channel *mo
 		if IsUniqueConstraintError(err, []string{"Name", "channels_name_teamid_key"}) {
 			dupChannel := model.Channel{}
 			s.GetMaster().SelectOne(&dupChannel, "SELECT * FROM Channels WHERE TeamId = :TeamId AND Name = :Name", map[string]interface{}{"TeamId": channel.TeamId, "Name": channel.Name})
-			return &dupChannel, model.NewAppError("SqlChannelStore.Save", store.CHANNEL_EXISTS_ERROR, nil, "id="+channel.Id+", "+err.Error(), http.StatusBadRequest)
+			return &dupChannel, store.NewErrConflict("Channel", err, "id="+channel.Id)
 		}
-		return nil, model.NewAppError("SqlChannelStore.Save", "store.sql_channel.save_channel.save.app_error", nil, "id="+channel.Id+", "+err.Error(), http.StatusInternalServerError)
+		return nil, errors.Wrapf(err, "save_channel: id=%s", channel.Id)
 	}
 	return channel, nil
 }

store/store.go

@@ -127,7 +127,7 @@ type TeamStore interface {
 }
 
 type ChannelStore interface {
-	Save(channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, *model.AppError)
+	Save(channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, error)
 	CreateDirectChannel(userId *model.User, otherUserId *model.User) (*model.Channel, *model.AppError)
 	SaveDirectChannel(channel *model.Channel, member1 *model.ChannelMember, member2 *model.ChannelMember) (*model.Channel, *model.AppError)
 	Update(channel *model.Channel) (*model.Channel, *model.AppError)

store/storetest/compliance_store.go

@@ -127,8 +127,8 @@ func testComplianceExport(t *testing.T, ss store.Store) {
 	c1.DisplayName = "Channel2"
 	c1.Name = "zz" + model.NewId() + "b"
 	c1.Type = model.CHANNEL_OPEN
-	c1, err = ss.Channel().Save(c1, -1)
+	c1, nErr := ss.Channel().Save(c1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	o1 := &model.Post{}
 	o1.ChannelId = c1.Id
@@ -236,8 +236,8 @@ func testComplianceExportDirectMessages(t *testing.T, ss store.Store) {
 	c1.DisplayName = "Channel2"
 	c1.Name = "zz" + model.NewId() + "b"
 	c1.Type = model.CHANNEL_OPEN
-	c1, err = ss.Channel().Save(c1, -1)
+	c1, nErr := ss.Channel().Save(c1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	cDM, err := ss.Channel().CreateDirectChannel(u1, u2)
 	require.Nil(t, err)
@@ -342,8 +342,8 @@ func testMessageExportPublicChannel(t *testing.T, ss store.Store) {
 		DisplayName: "Public Channel",
 		Type:        model.CHANNEL_OPEN,
 	}
-	channel, err = ss.Channel().Save(channel, -1)
+	channel, nErr := ss.Channel().Save(channel, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// user1 posts twice in the public channel
 	post1 := &model.Post{
@@ -446,8 +446,8 @@ func testMessageExportPrivateChannel(t *testing.T, ss store.Store) {
 		DisplayName: "Private Channel",
 		Type:        model.CHANNEL_PRIVATE,
 	}
-	channel, err = ss.Channel().Save(channel, -1)
+	channel, nErr := ss.Channel().Save(channel, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// user1 posts twice in the private channel
 	post1 := &model.Post{
@@ -644,8 +644,8 @@ func testMessageExportGroupMessageChannel(t *testing.T, ss store.Store) {
 		Name:   model.NewId(),
 		Type:   model.CHANNEL_GROUP,
 	}
-	groupMessageChannel, err = ss.Channel().Save(groupMessageChannel, -1)
+	groupMessageChannel, nErr := ss.Channel().Save(groupMessageChannel, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// user1 posts in the GM
 	post := &model.Post{
@@ -718,8 +718,8 @@ func testEditExportMessage(t *testing.T, ss store.Store) {
 		DisplayName: "Public Channel",
 		Type:        model.CHANNEL_OPEN,
 	}
-	channel, err = ss.Channel().Save(channel, -1)
+	channel, nErr := ss.Channel().Save(channel, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// user1 posts in the public channel
 	post1 := &model.Post{
@@ -811,8 +811,8 @@ func testEditAfterExportMessage(t *testing.T, ss store.Store) {
 		DisplayName: "Public Channel",
 		Type:        model.CHANNEL_OPEN,
 	}
-	channel, err = ss.Channel().Save(channel, -1)
+	channel, nErr := ss.Channel().Save(channel, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// user1 posts in the public channel
 	post1 := &model.Post{
@@ -923,8 +923,8 @@ func testDeleteExportMessage(t *testing.T, ss store.Store) {
 		DisplayName: "Public Channel",
 		Type:        model.CHANNEL_OPEN,
 	}
-	channel, err = ss.Channel().Save(channel, -1)
+	channel, nErr := ss.Channel().Save(channel, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// user1 posts in the public channel
 	post1 := &model.Post{
@@ -1008,8 +1008,8 @@ func testDeleteAfterExportMessage(t *testing.T, ss store.Store) {
 		DisplayName: "Public Channel",
 		Type:        model.CHANNEL_OPEN,
 	}
-	channel, err = ss.Channel().Save(channel, -1)
+	channel, nErr := ss.Channel().Save(channel, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// user1 posts in the public channel
 	post1 := &model.Post{

store/storetest/group_store.go

@@ -847,8 +847,8 @@ func testGroupGetMemberUsersNotInChannel(t *testing.T, ss store.Store) {
 		Name:        model.NewId(),
 		Type:        model.CHANNEL_OPEN, // Query does not look at type so this shouldn't matter.
 	}
-	channel, err = ss.Channel().Save(channel, 9999)
+	channel, nErr := ss.Channel().Save(channel, 9999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// returns no members when channel does not exist
 	groupMembers, err := ss.Group().GetMemberUsersNotInChannel(group.Id, "non-existant-channel-id")
@@ -1606,8 +1606,8 @@ func testChannelMembersToAdd(t *testing.T, ss store.Store) {
 		Name:        model.NewId(),
 		Type:        model.CHANNEL_OPEN, // Query does not look at type so this shouldn't matter.
 	}
-	channel, err = ss.Channel().Save(channel, 9999)
+	channel, nErr := ss.Channel().Save(channel, 9999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// Create GroupChannel
 	syncable, err := ss.Group().CreateGroupSyncable(model.NewGroupChannel(group.Id, channel.Id, true))
@@ -1796,16 +1796,16 @@ func testChannelMembersToAddSingleChannel(t *testing.T, ss store.Store) {
 		Name:        "z-z-" + model.NewId() + "a",
 		Type:        model.CHANNEL_OPEN,
 	}
-	channel1, err = ss.Channel().Save(channel1, 999)
+	channel1, nErr := ss.Channel().Save(channel1, 999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	channel2 := &model.Channel{
 		DisplayName: "Name",
 		Name:        "z-z-" + model.NewId() + "a",
 		Type:        model.CHANNEL_OPEN,
 	}
-	channel2, err = ss.Channel().Save(channel2, 999)
+	channel2, nErr = ss.Channel().Save(channel2, 999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	_, err = ss.Group().CreateGroupSyncable(model.NewGroupChannel(group1.Id, channel1.Id, true))
 	require.Nil(t, err)
@@ -2081,8 +2081,8 @@ func testChannelMembersToRemoveSingleChannel(t *testing.T, ss store.Store) {
 		Type:             model.CHANNEL_OPEN,
 		GroupConstrained: model.NewBool(true),
 	}
-	channel1, err = ss.Channel().Save(channel1, 999)
+	channel1, nErr := ss.Channel().Save(channel1, 999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	channel2 := &model.Channel{
 		DisplayName:      "Name",
@@ -2090,8 +2090,8 @@ func testChannelMembersToRemoveSingleChannel(t *testing.T, ss store.Store) {
 		Type:             model.CHANNEL_OPEN,
 		GroupConstrained: model.NewBool(true),
 	}
-	channel2, err = ss.Channel().Save(channel2, 999)
+	channel2, nErr = ss.Channel().Save(channel2, 999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	for _, user := range []*model.User{user1, user2} {
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{
@@ -2183,8 +2183,8 @@ func pendingMemberRemovalsDataSetup(t *testing.T, ss store.Store) *removalsData
 		Type:             model.CHANNEL_PRIVATE,
 		GroupConstrained: model.NewBool(true),
 	}
-	channelConstrained, err = ss.Channel().Save(channelConstrained, 9999)
+	channelConstrained, nErr := ss.Channel().Save(channelConstrained, 9999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	channelUnconstrained := &model.Channel{
 		TeamId:      model.NewId(),
@@ -2192,8 +2192,8 @@ func pendingMemberRemovalsDataSetup(t *testing.T, ss store.Store) *removalsData
 		Name:        model.NewId(),
 		Type:        model.CHANNEL_PRIVATE,
 	}
-	channelUnconstrained, err = ss.Channel().Save(channelUnconstrained, 9999)
+	channelUnconstrained, nErr = ss.Channel().Save(channelUnconstrained, 9999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// create teams
 	teamConstrained := &model.Team{
@@ -2344,8 +2344,8 @@ func testGetGroupsByChannel(t *testing.T, ss store.Store) {
 		Name:        model.NewId(),
 		Type:        model.CHANNEL_OPEN,
 	}
-	channel2, err = ss.Channel().Save(channel2, 9999)
+	channel2, nErr := ss.Channel().Save(channel2, 9999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// Create Group3
 	group3, err := ss.Group().Create(&model.Group{
@@ -3033,8 +3033,8 @@ func testGetGroups(t *testing.T, ss store.Store) {
 		Name:        model.NewId(),
 		Type:        model.CHANNEL_PRIVATE,
 	}
-	channel1, err = ss.Channel().Save(channel1, 9999)
+	channel1, nErr := ss.Channel().Save(channel1, 9999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// Create Groups 1 and 2
 	group1, err := ss.Group().Create(&model.Group{
@@ -3097,8 +3097,8 @@ func testGetGroups(t *testing.T, ss store.Store) {
 		Name:        model.NewId(),
 		Type:        model.CHANNEL_PRIVATE,
 	}
-	channel2, err = ss.Channel().Save(channel2, 9999)
+	channel2, nErr = ss.Channel().Save(channel2, 9999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	// Create Group3
 	group3, err := ss.Group().Create(&model.Group{
@@ -3761,8 +3761,8 @@ func groupTestAdminRoleGroupsForSyncableMemberChannel(t *testing.T, ss store.Sto
 		Name:        model.NewId(),
 		Type:        model.CHANNEL_OPEN,
 	}
-	channel, err = ss.Channel().Save(channel, 9999)
+	channel, nErr := ss.Channel().Save(channel, 9999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	_, err = ss.Group().CreateGroupSyncable(&model.GroupSyncable{
 		AutoAdd:     true,
@@ -4058,8 +4058,8 @@ func groupTestPermittedSyncableAdminsChannel(t *testing.T, ss store.Store) {
 		Name:        model.NewId(),
 		Type:        model.CHANNEL_OPEN,
 	}
-	channel, err = ss.Channel().Save(channel, 9999)
+	channel, nErr := ss.Channel().Save(channel, 9999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	_, err = ss.Group().CreateGroupSyncable(&model.GroupSyncable{
 		AutoAdd:     true,

store/storetest/mocks/ChannelStore.go

@@ -1424,7 +1424,7 @@ func (_m *ChannelStore) Restore(channelId string, time int64) *model.AppError {
 }
 
 // Save provides a mock function with given fields: channel, maxChannelsPerTeam
-func (_m *ChannelStore) Save(channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, *model.AppError) {
+func (_m *ChannelStore) Save(channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, error) {
 	ret := _m.Called(channel, maxChannelsPerTeam)
 
 	var r0 *model.Channel
@@ -1436,13 +1436,11 @@ func (_m *ChannelStore) Save(channel *model.Channel, maxChannelsPerTeam int64) (
 		}
 	}
 
-	var r1 *model.AppError
+	var r1 error
-	if rf, ok := ret.Get(1).(func(*model.Channel, int64) *model.AppError); ok {
+	if rf, ok := ret.Get(1).(func(*model.Channel, int64) error); ok {
 		r1 = rf(channel, maxChannelsPerTeam)
 	} else {
-		if ret.Get(1) != nil {
+		r1 = ret.Error(1)
-			r1 = ret.Get(1).(*model.AppError)
-		}
 	}
 
 	return r0, r1

store/storetest/post_store.go

@@ -1445,8 +1445,8 @@ func testUserCountsWithPostsByDay(t *testing.T, ss store.Store) {
 	c1.DisplayName = "Channel2"
 	c1.Name = "zz" + model.NewId() + "b"
 	c1.Type = model.CHANNEL_OPEN
-	c1, err = ss.Channel().Save(c1, -1)
+	c1, nErr := ss.Channel().Save(c1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	o1 := &model.Post{}
 	o1.ChannelId = c1.Id
@@ -1504,8 +1504,8 @@ func testPostCountsByDay(t *testing.T, ss store.Store) {
 	c1.DisplayName = "Channel2"
 	c1.Name = "zz" + model.NewId() + "b"
 	c1.Type = model.CHANNEL_OPEN
-	c1, err = ss.Channel().Save(c1, -1)
+	c1, nErr := ss.Channel().Save(c1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	o1 := &model.Post{}
 	o1.ChannelId = c1.Id
@@ -2415,8 +2415,8 @@ func testPostStoreGetParentsForExportAfter(t *testing.T, ss store.Store) {
 	c1.DisplayName = "Channel1"
 	c1.Name = "zz" + model.NewId() + "b"
 	c1.Type = model.CHANNEL_OPEN
-	_, err = ss.Channel().Save(&c1, -1)
+	_, nErr := ss.Channel().Save(&c1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	u1 := model.User{}
 	u1.Username = model.NewId()
@@ -2464,8 +2464,8 @@ func testPostStoreGetRepliesForExport(t *testing.T, ss store.Store) {
 	c1.DisplayName = "Channel1"
 	c1.Name = "zz" + model.NewId() + "b"
 	c1.Type = model.CHANNEL_OPEN
-	_, err = ss.Channel().Save(&c1, -1)
+	_, nErr := ss.Channel().Save(&c1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	u1 := model.User{}
 	u1.Email = MakeEmail()

store/storetest/role_store.go

@@ -432,8 +432,8 @@ func testRoleStoreLowerScopedChannelSchemeRoles(t *testing.T, ss store.Store) {
 		Type:        model.CHANNEL_OPEN,
 		SchemeId:    &channelScheme1.Id,
 	}
-	channel1, err = ss.Channel().Save(channel1, -1)
+	channel1, nErr := ss.Channel().Save(channel1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 	defer ss.Channel().Delete(channel1.Id, 0)
 
 	channel2 := &model.Channel{
@@ -443,8 +443,8 @@ func testRoleStoreLowerScopedChannelSchemeRoles(t *testing.T, ss store.Store) {
 		Type:        model.CHANNEL_OPEN,
 		SchemeId:    &channelScheme2.Id,
 	}
-	channel2, err = ss.Channel().Save(channel2, -1)
+	channel2, nErr = ss.Channel().Save(channel2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 	defer ss.Channel().Delete(channel2.Id, 0)
 
 	t.Run("ChannelRolesUnderTeamRole", func(t *testing.T) {
@@ -555,8 +555,8 @@ func testRoleStoreChannelHigherScopedPermissionsBlankTeamSchemeChannelGuest(t *t
 		Type:        model.CHANNEL_OPEN,
 		SchemeId:    &channelScheme.Id,
 	}
-	channel, err = ss.Channel().Save(channel, -1)
+	channel, nErr := ss.Channel().Save(channel, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 	defer ss.Channel().Delete(channel.Id, 0)
 
 	channelSchemeUserRole, err := ss.Role().GetByName(channelScheme.DefaultChannelUserRole)

store/storetest/scheme_store.go

@@ -444,8 +444,8 @@ func testSchemeStoreDelete(t *testing.T, ss store.Store) {
 		Type:        model.CHANNEL_OPEN,
 		SchemeId:    &d5.Id,
 	}
-	c5, err = ss.Channel().Save(c5, -1)
+	c5, nErr := ss.Channel().Save(c5, -1)
-	assert.Nil(t, err)
+	assert.Nil(t, nErr)
 
 	_, err = ss.Scheme().Delete(d5.Id)
 	assert.Nil(t, err)

store/storetest/team_store.go

@@ -2808,12 +2808,12 @@ func testGetChannelUnreadsForAllTeams(t *testing.T, ss store.Store) {
 	require.Nil(t, err)
 
 	c1 := &model.Channel{TeamId: m1.TeamId, Name: model.NewId(), DisplayName: "Town Square", Type: model.CHANNEL_OPEN, TotalMsgCount: 100}
-	_, err = ss.Channel().Save(c1, -1)
+	_, nErr := ss.Channel().Save(c1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	c2 := &model.Channel{TeamId: m2.TeamId, Name: model.NewId(), DisplayName: "Town Square", Type: model.CHANNEL_OPEN, TotalMsgCount: 100}
-	_, err = ss.Channel().Save(c2, -1)
+	_, nErr = ss.Channel().Save(c2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	cm1 := &model.ChannelMember{ChannelId: c1.Id, UserId: m1.UserId, NotifyProps: model.GetDefaultChannelNotifyProps(), MsgCount: 90}
 	_, err = ss.Channel().SaveMember(cm1)
@@ -2862,12 +2862,12 @@ func testGetChannelUnreadsForTeam(t *testing.T, ss store.Store) {
 	require.Nil(t, err)
 
 	c1 := &model.Channel{TeamId: m1.TeamId, Name: model.NewId(), DisplayName: "Town Square", Type: model.CHANNEL_OPEN, TotalMsgCount: 100}
-	_, err = ss.Channel().Save(c1, -1)
+	_, nErr := ss.Channel().Save(c1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	c2 := &model.Channel{TeamId: m1.TeamId, Name: model.NewId(), DisplayName: "Town Square", Type: model.CHANNEL_OPEN, TotalMsgCount: 100}
-	_, err = ss.Channel().Save(c2, -1)
+	_, nErr = ss.Channel().Save(c2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	cm1 := &model.ChannelMember{ChannelId: c1.Id, UserId: m1.UserId, NotifyProps: model.GetDefaultChannelNotifyProps(), MsgCount: 90}
 	_, err = ss.Channel().SaveMember(cm1)

store/storetest/user_store.go

@@ -700,8 +700,8 @@ func testUserStoreGetProfilesInChannel(t *testing.T, ss store.Store) {
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_OPEN,
 	}
-	c1, err := ss.Channel().Save(ch1, -1)
+	c1, nErr := ss.Channel().Save(ch1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	ch2 := &model.Channel{
 		TeamId:      teamId,
@@ -709,8 +709,8 @@ func testUserStoreGetProfilesInChannel(t *testing.T, ss store.Store) {
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_PRIVATE,
 	}
-	c2, err := ss.Channel().Save(ch2, -1)
+	c2, nErr := ss.Channel().Save(ch2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	_, err = ss.Channel().SaveMember(&model.ChannelMember{
 		ChannelId:   c1.Id,
@@ -805,8 +805,8 @@ func testUserStoreGetProfilesInChannelByStatus(t *testing.T, ss store.Store, s S
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_OPEN,
 	}
-	c1, err := ss.Channel().Save(ch1, -1)
+	c1, nErr := ss.Channel().Save(ch1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	ch2 := &model.Channel{
 		TeamId:      teamId,
@@ -814,8 +814,8 @@ func testUserStoreGetProfilesInChannelByStatus(t *testing.T, ss store.Store, s S
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_PRIVATE,
 	}
-	c2, err := ss.Channel().Save(ch2, -1)
+	c2, nErr := ss.Channel().Save(ch2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	_, err = ss.Channel().SaveMember(&model.ChannelMember{
 		ChannelId:   c1.Id,
@@ -981,8 +981,8 @@ func testUserStoreGetAllProfilesInChannel(t *testing.T, ss store.Store) {
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_OPEN,
 	}
-	c1, err := ss.Channel().Save(ch1, -1)
+	c1, nErr := ss.Channel().Save(ch1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	ch2 := &model.Channel{
 		TeamId:      teamId,
@@ -990,8 +990,8 @@ func testUserStoreGetAllProfilesInChannel(t *testing.T, ss store.Store) {
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_PRIVATE,
 	}
-	c2, err := ss.Channel().Save(ch2, -1)
+	c2, nErr := ss.Channel().Save(ch2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	_, err = ss.Channel().SaveMember(&model.ChannelMember{
 		ChannelId:   c1.Id,
@@ -1109,8 +1109,8 @@ func testUserStoreGetProfilesNotInChannel(t *testing.T, ss store.Store) {
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_OPEN,
 	}
-	c1, err := ss.Channel().Save(ch1, -1)
+	c1, nErr := ss.Channel().Save(ch1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	ch2 := &model.Channel{
 		TeamId:      teamId,
@@ -1118,8 +1118,8 @@ func testUserStoreGetProfilesNotInChannel(t *testing.T, ss store.Store) {
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_PRIVATE,
 	}
-	c2, err := ss.Channel().Save(ch2, -1)
+	c2, nErr := ss.Channel().Save(ch2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	t.Run("get team 1, channel 1, offset 0, limit 100", func(t *testing.T) {
 		var profiles []*model.User
@@ -1343,12 +1343,12 @@ func testUserStoreGetProfileByGroupChannelIdsForUser(t *testing.T, ss store.Stor
 	require.Nil(t, err)
 	defer func() { require.Nil(t, ss.User().PermanentDelete(u4.Id)) }()
 
-	gc1, err := ss.Channel().Save(&model.Channel{
+	gc1, nErr := ss.Channel().Save(&model.Channel{
 		DisplayName: "Profiles in private",
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_GROUP,
 	}, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	for _, uId := range []string{u1.Id, u2.Id, u3.Id} {
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{
@@ -1359,12 +1359,12 @@ func testUserStoreGetProfileByGroupChannelIdsForUser(t *testing.T, ss store.Stor
 		require.Nil(t, err)
 	}
 
-	gc2, err := ss.Channel().Save(&model.Channel{
+	gc2, nErr := ss.Channel().Save(&model.Channel{
 		DisplayName: "Profiles in private",
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_GROUP,
 	}, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	for _, uId := range []string{u1.Id, u3.Id, u4.Id} {
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{
@@ -1952,8 +1952,8 @@ func testUserUnreadCount(t *testing.T, ss store.Store) {
 	_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId, UserId: u2.Id}, -1)
 	require.Nil(t, err)
 
-	_, err = ss.Channel().Save(&c1, -1)
+	_, nErr := ss.Channel().Save(&c1, -1)
-	require.Nil(t, err, "couldn't save item")
+	require.Nil(t, nErr, "couldn't save item")
 
 	m1 := model.ChannelMember{}
 	m1.ChannelId = c1.Id
@@ -2289,8 +2289,8 @@ func testUserStoreSearchNotInChannel(t *testing.T, ss store.Store) {
 		Name:        "zz" + model.NewId() + "b",
 		Type:        model.CHANNEL_OPEN,
 	}
-	c1, err := ss.Channel().Save(&ch1, -1)
+	c1, nErr := ss.Channel().Save(&ch1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	ch2 := model.Channel{
 		TeamId:      tid,
@@ -2298,8 +2298,8 @@ func testUserStoreSearchNotInChannel(t *testing.T, ss store.Store) {
 		Name:        "zz" + model.NewId() + "b",
 		Type:        model.CHANNEL_OPEN,
 	}
-	c2, err := ss.Channel().Save(&ch2, -1)
+	c2, nErr := ss.Channel().Save(&ch2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	_, err = ss.Channel().SaveMember(&model.ChannelMember{
 		ChannelId:   c2.Id,
@@ -2515,8 +2515,8 @@ func testUserStoreSearchInChannel(t *testing.T, ss store.Store) {
 		Name:        "zz" + model.NewId() + "b",
 		Type:        model.CHANNEL_OPEN,
 	}
-	c1, err := ss.Channel().Save(&ch1, -1)
+	c1, nErr := ss.Channel().Save(&ch1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	ch2 := model.Channel{
 		TeamId:      tid,
@@ -2524,8 +2524,8 @@ func testUserStoreSearchInChannel(t *testing.T, ss store.Store) {
 		Name:        "zz" + model.NewId() + "b",
 		Type:        model.CHANNEL_OPEN,
 	}
-	c2, err := ss.Channel().Save(&ch2, -1)
+	c2, nErr := ss.Channel().Save(&ch2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	_, err = ss.Channel().SaveMember(&model.ChannelMember{
 		ChannelId:   c1.Id,
@@ -3524,23 +3524,23 @@ func testUserStoreGetUsersBatchForIndexing(t *testing.T, ss store.Store) {
 		Name: model.NewId(),
 		Type: model.CHANNEL_OPEN,
 	}
-	cPub1, err := ss.Channel().Save(ch1, -1)
+	cPub1, nErr := ss.Channel().Save(ch1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	ch2 := &model.Channel{
 		Name: model.NewId(),
 		Type: model.CHANNEL_OPEN,
 	}
-	cPub2, err := ss.Channel().Save(ch2, -1)
+	cPub2, nErr := ss.Channel().Save(ch2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	ch3 := &model.Channel{
 		Name: model.NewId(),
 		Type: model.CHANNEL_PRIVATE,
 	}
 
-	cPriv, err := ss.Channel().Save(ch3, -1)
+	cPriv, nErr := ss.Channel().Save(ch3, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	u1, err := ss.User().Save(&model.User{
 		Email:    MakeEmail(),
@@ -3770,12 +3770,12 @@ func testUserStoreGetTeamGroupUsers(t *testing.T, ss store.Store) {
 func testUserStoreGetChannelGroupUsers(t *testing.T, ss store.Store) {
 	// create channel
 	id := model.NewId()
-	channel, err := ss.Channel().Save(&model.Channel{
+	channel, nErr := ss.Channel().Save(&model.Channel{
 		DisplayName: "dn_" + id,
 		Name:        "n-" + id,
 		Type:        model.CHANNEL_PRIVATE,
 	}, 999)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 	require.NotNil(t, channel)
 
 	// create users
@@ -3798,7 +3798,7 @@ func testUserStoreGetChannelGroupUsers(t *testing.T, ss store.Store) {
 	userGroupA, userGroupB, userNoGroup := testUsers[0], testUsers[1], testUsers[2]
 
 	// add non-group-member to the channel (to prove that the query isn't just returning all members)
-	_, err = ss.Channel().SaveMember(&model.ChannelMember{
+	_, err := ss.Channel().SaveMember(&model.ChannelMember{
 		ChannelId:   channel.Id,
 		UserId:      userNoGroup.Id,
 		NotifyProps: model.GetDefaultChannelNotifyProps(),
@@ -3908,13 +3908,13 @@ func testUserStorePromoteGuestToUser(t *testing.T, ss store.Store) {
 		_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId, UserId: user.Id, SchemeGuest: true, SchemeUser: false}, 999)
 		require.Nil(t, err)
 
-		channel, err := ss.Channel().Save(&model.Channel{
+		channel, nErr := ss.Channel().Save(&model.Channel{
 			TeamId:      teamId,
 			DisplayName: "Channel name",
 			Name:        "channel-" + model.NewId(),
 			Type:        model.CHANNEL_OPEN,
 		}, -1)
-		require.Nil(t, err)
+		require.Nil(t, nErr)
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{ChannelId: channel.Id, UserId: user.Id, SchemeGuest: true, SchemeUser: false, NotifyProps: model.GetDefaultChannelNotifyProps()})
 		require.Nil(t, err)
 
@@ -3954,13 +3954,13 @@ func testUserStorePromoteGuestToUser(t *testing.T, ss store.Store) {
 		_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId, UserId: user.Id, SchemeGuest: true, SchemeUser: false}, 999)
 		require.Nil(t, err)
 
-		channel, err := ss.Channel().Save(&model.Channel{
+		channel, nErr := ss.Channel().Save(&model.Channel{
 			TeamId:      teamId,
 			DisplayName: "Channel name",
 			Name:        "channel-" + model.NewId(),
 			Type:        model.CHANNEL_OPEN,
 		}, -1)
-		require.Nil(t, err)
+		require.Nil(t, nErr)
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{ChannelId: channel.Id, UserId: user.Id, SchemeGuest: true, SchemeUser: false, NotifyProps: model.GetDefaultChannelNotifyProps()})
 		require.Nil(t, err)
 
@@ -4050,13 +4050,13 @@ func testUserStorePromoteGuestToUser(t *testing.T, ss store.Store) {
 		_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId, UserId: user.Id, SchemeGuest: true, SchemeUser: false}, 999)
 		require.Nil(t, err)
 
-		channel, err := ss.Channel().Save(&model.Channel{
+		channel, nErr := ss.Channel().Save(&model.Channel{
 			TeamId:      teamId,
 			DisplayName: "Channel name",
 			Name:        "channel-" + model.NewId(),
 			Type:        model.CHANNEL_OPEN,
 		}, -1)
-		require.Nil(t, err)
+		require.Nil(t, nErr)
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{ChannelId: channel.Id, UserId: user.Id, SchemeGuest: true, SchemeUser: false, NotifyProps: model.GetDefaultChannelNotifyProps()})
 		require.Nil(t, err)
 
@@ -4095,13 +4095,13 @@ func testUserStorePromoteGuestToUser(t *testing.T, ss store.Store) {
 		_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId, UserId: user.Id, SchemeGuest: true, SchemeUser: false}, 999)
 		require.Nil(t, err)
 
-		channel, err := ss.Channel().Save(&model.Channel{
+		channel, nErr := ss.Channel().Save(&model.Channel{
 			TeamId:      teamId,
 			DisplayName: "Channel name",
 			Name:        "channel-" + model.NewId(),
 			Type:        model.CHANNEL_OPEN,
 		}, -1)
-		require.Nil(t, err)
+		require.Nil(t, nErr)
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{ChannelId: channel.Id, UserId: user.Id, SchemeGuest: true, SchemeUser: false, NotifyProps: model.GetDefaultChannelNotifyProps()})
 		require.Nil(t, err)
 
@@ -4140,13 +4140,13 @@ func testUserStorePromoteGuestToUser(t *testing.T, ss store.Store) {
 		_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId1, UserId: user1.Id, SchemeGuest: true, SchemeUser: false}, 999)
 		require.Nil(t, err)
 
-		channel, err := ss.Channel().Save(&model.Channel{
+		channel, nErr := ss.Channel().Save(&model.Channel{
 			TeamId:      teamId1,
 			DisplayName: "Channel name",
 			Name:        "channel-" + model.NewId(),
 			Type:        model.CHANNEL_OPEN,
 		}, -1)
-		require.Nil(t, err)
+		require.Nil(t, nErr)
 
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{ChannelId: channel.Id, UserId: user1.Id, SchemeGuest: true, SchemeUser: false, NotifyProps: model.GetDefaultChannelNotifyProps()})
 		require.Nil(t, err)
@@ -4223,13 +4223,13 @@ func testUserStoreDemoteUserToGuest(t *testing.T, ss store.Store) {
 		_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId, UserId: user.Id, SchemeGuest: false, SchemeUser: true}, 999)
 		require.Nil(t, err)
 
-		channel, err := ss.Channel().Save(&model.Channel{
+		channel, nErr := ss.Channel().Save(&model.Channel{
 			TeamId:      teamId,
 			DisplayName: "Channel name",
 			Name:        "channel-" + model.NewId(),
 			Type:        model.CHANNEL_OPEN,
 		}, -1)
-		require.Nil(t, err)
+		require.Nil(t, nErr)
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{ChannelId: channel.Id, UserId: user.Id, SchemeGuest: false, SchemeUser: true, NotifyProps: model.GetDefaultChannelNotifyProps()})
 		require.Nil(t, err)
 
@@ -4269,13 +4269,13 @@ func testUserStoreDemoteUserToGuest(t *testing.T, ss store.Store) {
 		_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId, UserId: user.Id, SchemeGuest: true, SchemeUser: false}, 999)
 		require.Nil(t, err)
 
-		channel, err := ss.Channel().Save(&model.Channel{
+		channel, nErr := ss.Channel().Save(&model.Channel{
 			TeamId:      teamId,
 			DisplayName: "Channel name",
 			Name:        "channel-" + model.NewId(),
 			Type:        model.CHANNEL_OPEN,
 		}, -1)
-		require.Nil(t, err)
+		require.Nil(t, nErr)
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{ChannelId: channel.Id, UserId: user.Id, SchemeGuest: true, SchemeUser: false, NotifyProps: model.GetDefaultChannelNotifyProps()})
 		require.Nil(t, err)
 
@@ -4365,13 +4365,13 @@ func testUserStoreDemoteUserToGuest(t *testing.T, ss store.Store) {
 		_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId, UserId: user.Id, SchemeGuest: false, SchemeUser: true}, 999)
 		require.Nil(t, err)
 
-		channel, err := ss.Channel().Save(&model.Channel{
+		channel, nErr := ss.Channel().Save(&model.Channel{
 			TeamId:      teamId,
 			DisplayName: "Channel name",
 			Name:        "channel-" + model.NewId(),
 			Type:        model.CHANNEL_OPEN,
 		}, -1)
-		require.Nil(t, err)
+		require.Nil(t, nErr)
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{ChannelId: channel.Id, UserId: user.Id, SchemeGuest: false, SchemeUser: true, NotifyProps: model.GetDefaultChannelNotifyProps()})
 		require.Nil(t, err)
 
@@ -4410,13 +4410,13 @@ func testUserStoreDemoteUserToGuest(t *testing.T, ss store.Store) {
 		_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId, UserId: user.Id, SchemeGuest: false, SchemeUser: true}, 999)
 		require.Nil(t, err)
 
-		channel, err := ss.Channel().Save(&model.Channel{
+		channel, nErr := ss.Channel().Save(&model.Channel{
 			TeamId:      teamId,
 			DisplayName: "Channel name",
 			Name:        "channel-" + model.NewId(),
 			Type:        model.CHANNEL_OPEN,
 		}, -1)
-		require.Nil(t, err)
+		require.Nil(t, nErr)
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{ChannelId: channel.Id, UserId: user.Id, SchemeGuest: false, SchemeUser: true, NotifyProps: model.GetDefaultChannelNotifyProps()})
 		require.Nil(t, err)
 
@@ -4455,13 +4455,13 @@ func testUserStoreDemoteUserToGuest(t *testing.T, ss store.Store) {
 		_, err = ss.Team().SaveMember(&model.TeamMember{TeamId: teamId1, UserId: user1.Id, SchemeGuest: false, SchemeUser: true}, 999)
 		require.Nil(t, err)
 
-		channel, err := ss.Channel().Save(&model.Channel{
+		channel, nErr := ss.Channel().Save(&model.Channel{
 			TeamId:      teamId1,
 			DisplayName: "Channel name",
 			Name:        "channel-" + model.NewId(),
 			Type:        model.CHANNEL_OPEN,
 		}, -1)
-		require.Nil(t, err)
+		require.Nil(t, nErr)
 
 		_, err = ss.Channel().SaveMember(&model.ChannelMember{ChannelId: channel.Id, UserId: user1.Id, SchemeGuest: false, SchemeUser: true, NotifyProps: model.GetDefaultChannelNotifyProps()})
 		require.Nil(t, err)
@@ -4680,8 +4680,8 @@ func testGetKnownUsers(t *testing.T, ss store.Store) {
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_OPEN,
 	}
-	c1, err := ss.Channel().Save(ch1, -1)
+	c1, nErr := ss.Channel().Save(ch1, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	ch2 := &model.Channel{
 		TeamId:      teamId,
@@ -4689,8 +4689,8 @@ func testGetKnownUsers(t *testing.T, ss store.Store) {
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_PRIVATE,
 	}
-	c2, err := ss.Channel().Save(ch2, -1)
+	c2, nErr := ss.Channel().Save(ch2, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	ch3 := &model.Channel{
 		TeamId:      teamId,
@@ -4698,8 +4698,8 @@ func testGetKnownUsers(t *testing.T, ss store.Store) {
 		Name:        "profiles-" + model.NewId(),
 		Type:        model.CHANNEL_PRIVATE,
 	}
-	c3, err := ss.Channel().Save(ch3, -1)
+	c3, nErr := ss.Channel().Save(ch3, -1)
-	require.Nil(t, err)
+	require.Nil(t, nErr)
 
 	_, err = ss.Channel().SaveMember(&model.ChannelMember{
 		ChannelId:   c1.Id,

store/timer_layer.go

@@ -1553,7 +1553,7 @@ func (s *TimerLayerChannelStore) Restore(channelId string, time int64) *model.Ap
 	return resultVar0
 }
 
-func (s *TimerLayerChannelStore) Save(channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, *model.AppError) {
+func (s *TimerLayerChannelStore) Save(channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, error) {
 	start := timemodule.Now()
 
 	resultVar0, resultVar1 := s.ChannelStore.Save(channel, maxChannelsPerTeam)