Enforce channel display name limits on slash command (#7309)

app/command_channel_rename.go

@@ -53,6 +53,10 @@ func (me *RenameProvider) DoCommand(args *model.CommandArgs, message string) *mo
 
 	if len(message) == 0 {
 		return &model.CommandResponse{Text: args.T("api.command_channel_rename.message.app_error"), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
+	} else if len(message) > model.CHANNEL_NAME_UI_MAX_LENGTH {
+		return &model.CommandResponse{Text: args.T("api.command_channel_rename.too_long.app_error", map[string]interface{}{"Length": len(message)}), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
+	} else if len(message) < model.CHANNEL_NAME_MIN_LENGTH {
+		return &model.CommandResponse{Text: args.T("api.command_channel_rename.too_short.app_error", map[string]interface{}{"Length": len(message)}), ResponseType: model.COMMAND_RESPONSE_TYPE_EPHEMERAL}
 	}
 
 	patch := &model.ChannelPatch{

app/command_channel_rename_test.go

@@ -0,0 +1,31 @@
+package app
+
+import (
+	"testing"
+
+	"github.com/mattermost/platform/model"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRenameProviderDoCommand(t *testing.T) {
+	th := Setup().InitBasic()
+
+	rp := RenameProvider{}
+	args := &model.CommandArgs{
+		T:         func(s string, args ...interface{}) string { return s },
+		ChannelId: th.BasicChannel.Id,
+		Session:   model.Session{UserId: th.BasicUser.Id, TeamMembers: []*model.TeamMember{&model.TeamMember{TeamId: th.BasicTeam.Id, Roles: model.ROLE_TEAM_USER.Id}}},
+	}
+
+	// Blank text is a success
+	for msg, expected := range map[string]string{
+		"":                        "api.command_channel_rename.message.app_error",
+		"o":                       "api.command_channel_rename.too_short.app_error",
+		"joram":                   "",
+		"1234567890123456789012":  "",
+		"12345678901234567890123": "api.command_channel_rename.too_long.app_error",
+	} {
+		actual := rp.DoCommand(args, msg).Text
+		assert.Equal(t, expected, actual)
+	}
+}

i18n/en.json

@@ -583,6 +583,14 @@
     "id": "api.command_channel_rename.message.app_error",
     "translation": "A message must be provided with the /rename command."
   },
+  {
+    "id": "api.command_channel_rename.too_long.app_error",
+    "translation": "Channel name must be {{.Length}} or fewer characters"
+  },
+  {
+    "id": "api.command_channel_rename.too_short.app_error",
+    "translation": "Channel name must be {{.Length}} or more characters"
+  },
   {
     "id": "api.command_channel_rename.name",
     "translation": "rename"

model/channel.go

@@ -24,6 +24,7 @@ const (
 	CHANNEL_DISPLAY_NAME_MAX_RUNES = 64
 	CHANNEL_NAME_MIN_LENGTH        = 2
 	CHANNEL_NAME_MAX_LENGTH        = 64
+	CHANNEL_NAME_UI_MAX_LENGTH     = 22
 	CHANNEL_HEADER_MAX_RUNES       = 1024
 	CHANNEL_PURPOSE_MAX_RUNES      = 250
 	CHANNEL_CACHE_SIZE             = 25000