Add tear down to APIv4 tests (#5250)

* Add tear down to APIv4 tests

* Defer tear downs

store/sql_channel_store.go

@@ -410,6 +410,41 @@ func (s SqlChannelStore) PermanentDeleteByTeam(teamId string) StoreChannel {
 	return storeChannel
 }
 
+func (s SqlChannelStore) PermanentDelete(channelId string) StoreChannel {
+	storeChannel := make(StoreChannel, 1)
+
+	go func() {
+		result := StoreResult{}
+
+		if _, err := s.GetMaster().Exec("DELETE FROM Channels WHERE Id = :ChannelId", map[string]interface{}{"ChannelId": channelId}); err != nil {
+			result.Err = model.NewLocAppError("SqlChannelStore.PermanentDelete", "store.sql_channel.permanent_delete.app_error", nil, "channel_id="+channelId+", "+err.Error())
+		}
+
+		storeChannel <- result
+		close(storeChannel)
+	}()
+
+	return storeChannel
+}
+
+func (s SqlChannelStore) PermanentDeleteMembersByChannel(channelId string) StoreChannel {
+	storeChannel := make(StoreChannel, 1)
+
+	go func() {
+		result := StoreResult{}
+
+		_, err := s.GetMaster().Exec("DELETE FROM ChannelMembers WHERE ChannelId = :ChannelId", map[string]interface{}{"ChannelId": channelId})
+		if err != nil {
+			result.Err = model.NewLocAppError("SqlChannelStore.RemoveAllMembersByChannel", "store.sql_channel.remove_member.app_error", nil, "channel_id="+channelId+", "+err.Error())
+		}
+
+		storeChannel <- result
+		close(storeChannel)
+	}()
+
+	return storeChannel
+}
+
 type channelWithMember struct {
 	model.Channel
 	model.ChannelMember