server: remove warning on private implicit val

[toshihidetagami]

This pull request removes parts of the server warning (Related to Issue #4 ).

Warnings.

[warn]  [E1] app/controllers/ChannelsController.scala
[warn]       private val messageFormat in object ChannelsController is never used
[warn]       L38:  private implicit val messageFormat: Format[Message] = wrapperFormat[Message, Base64String](Message.apply, _.base64)
[warn]       L38:                       ^
[warn]  [E2] app/controllers/ChannelsController.scala
[warn]       private val channelNameFormat in object ChannelsController is never used
[warn]       L57:  private implicit val channelNameFormat: Format[Channel.Name] = safeWrapperFormat[Channel.Name, String](Channel.Name.from, _.string)
[warn]       L57:                       ^
[warn]  [E3] app/controllers/ChannelsController.scala
[warn]       private val channelSecretFormat in object ChannelsController is never used
[warn]       L58:  private implicit val channelSecretFormat: Format[Channel.Secret] = wrapperFormat[Channel.Secret, String](Channel.Secret.apply, _.string)
[warn]       L58:                       ^
[warn]  [E4] app/controllers/ChannelsController.scala
[warn]       private val peerFormat in object ChannelsController is never used
[warn]       L60:  private implicit val peerFormat: Format[Peer] = new Format[Peer] {
[warn]       L60:   

Solution

Those warnings seem false positive and if you remove the code, it becomes compile error.
By adding -Ywarn-macros:after option, you can remove the warnings.

Reference
scala/bug#10599

[AlexITC]

Thanks!