chore: init from code-review-graph-main snapshot (v2.3.7)

tests/fixtures/sample.scala

@@ -0,0 +1,37 @@
+package com.example.auth
+
+import scala.collection.mutable
+import scala.collection.mutable.{HashMap, ListBuffer}
+import scala.util.Try
+import scala.concurrent._
+
+trait Repository[T]:
+  def findById(id: Int): Option[T]
+  def save(entity: T): Unit
+
+case class User(id: Int, name: String, email: String)
+
+class InMemoryRepo extends Repository[User] with Serializable:
+  private val users = mutable.HashMap[Int, User]()
+
+  override def findById(id: Int): Option[User] =
+    users.get(id)
+
+  override def save(user: User): Unit =
+    users.put(user.id, user)
+    println(s"Saved user ${user.id}")
+
+class UserService(repo: Repository[User]):
+  def createUser(name: String, email: String): User =
+    val user = User(1, name, email)
+    repo.save(user)
+    user
+
+  def getUser(id: Int): Option[User] =
+    repo.findById(id)
+
+object UserService:
+  def apply(repo: Repository[User]): UserService = new UserService(repo)
+
+enum Color:
+  case Red, Green, Blue