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>

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, err := a.Srv().Store.Channel().Save(channel, *a.Config().TeamSettings.MaxChannelsPerTeam)
-	if err != nil {
-		return nil, err
+	sc, nErr := a.Srv().Store.Channel().Save(channel, *a.Config().TeamSettings.MaxChannelsPerTeam)
+	if nErr != nil {
+		var invErr *store.ErrInvalidInput
+		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)
-	if err != nil {
-		if err.Id == store.CHANNEL_EXISTS_ERROR {
-			return channel, err
+	channel, nErr := a.Srv().Store.Channel().Save(group, *a.Config().TeamSettings.MaxChannelsPerTeam)
+	if nErr != nil {
+		var invErr *store.ErrInvalidInput
+		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 {