fix PeerSimple cannot be treated as entity

src/main/scala/com/fluency03/blockchain/core/Peer.scala

@@ -1,7 +1,4 @@
 package com.fluency03.blockchain.core
 
-trait PeerSimple {
-  def name: String
-}
-
-case class Peer(name: String, publicKeys: Set[String]) extends PeerSimple
+case class PeerSimple(name: String)
+case class Peer(name: String, publicKeys: Set[String])

src/main/scala/com/fluency03/blockchain/package.scala

@@ -5,6 +5,7 @@ import java.security.{MessageDigest, PrivateKey, PublicKey}
 import java.time.Instant
 
 import com.fluency03.blockchain.Crypto.{privateKeyToHex, publicKeyToHex}
+import com.fluency03.blockchain.core.{Peer, PeerSimple}
 import org.bouncycastle.util.encoders.{Base64, Hex}
 import org.json4s.{Formats, NoTypeHints}
 import org.json4s.native.Serialization
@@ -50,6 +51,10 @@ package object blockchain {
     def toHex: String = privateKeyToHex(privateKey)
   }
 
+  implicit class PeerImplicit(val peer: Peer) {
+    def toSimple: PeerSimple = PeerSimple(peer.name)
+  }
+
 
   /**
    * Generate SHA256 Hash from a input String.

src/test/scala/com/fluency03/blockchain/core/PeerTest.scala

@@ -8,8 +8,11 @@ class PeerTest extends FlatSpec with Matchers {
     val p = Peer("peer", Set("abcd"))
     p.name shouldEqual "peer"
     p.publicKeys shouldEqual Set("abcd")
-    p shouldBe a[PeerSimple]
     p shouldBe a[Peer]
+    p should not be a[PeerSimple]
+    val ps = p.toSimple
+    ps shouldBe a[PeerSimple]
+    ps.name shouldEqual "peer"
   }
 
 }