Implement JSON-RPC and LSP with Monix

build.sbt

@@ -8,7 +8,9 @@ inThisBuild(
       scalaVersion := V.scala212,
       scalacOptions ++= List(
         "-deprecation",
-        "-Xlint"
+        // -Xlint is unusable because of
+        // https://github.com/scala/bug/issues/10448
+        "-Ywarn-unused:imports"
       ),
       scalafixEnabled := false,
       organization := "org.scalameta",
@@ -55,7 +57,10 @@ inThisBuild(
       bintrayReleaseOnPublish := dynverGitDescribeOutput.value.isVersionStable,
       // faster publishLocal:
       publishArtifact in packageDoc := sys.env.contains("CI"),
-      publishArtifact in packageSrc := sys.env.contains("CI")
+      publishArtifact in packageSrc := sys.env.contains("CI"),
+      addCompilerPlugin(
+        "org.scalamacros" % "paradise" % "2.1.0" cross CrossVersion.full
+      )
     )
 )
 
@@ -64,6 +69,8 @@ lazy val V = new {
   val scalameta = "2.1.5"
   val scalafix = "0.5.7"
   val enumeratum = "1.5.12"
+  val circe = "0.9.0"
+  val cats = "1.0.1"
 }
 
 lazy val noPublish = List(
@@ -84,11 +91,14 @@ lazy val semanticdbSettings = List(
 
 lazy val languageserver = project
   .settings(
-    resolvers += Resolver.bintrayRepo("dhpcs", "maven"),
     libraryDependencies ++= Seq(
-      "com.dhpcs" %% "scala-json-rpc" % "2.0.1",
+      "io.circe" %% "circe-core" % V.circe,
+      "io.circe" %% "circe-generic" % V.circe,
+      "io.circe" %% "circe-generic-extras" % V.circe,
+      "io.circe" %% "circe-parser" % V.circe,
+      "org.typelevel" %% "cats-core" % V.cats,
       "com.beachape" %% "enumeratum" % V.enumeratum,
-      "com.beachape" %% "enumeratum-play-json" % "1.5.12-2.6.0-M7",
+      "com.beachape" %% "enumeratum-circe" % "1.5.15",
       "com.typesafe.scala-logging" %% "scala-logging" % "3.7.2",
       "io.monix" %% "monix" % "2.3.0",
       "org.slf4j" % "slf4j-api" % "1.7.25",
@@ -105,7 +115,6 @@ lazy val metaserver = project
         flatPackage = true // Don't append filename to package
       ) -> sourceManaged.in(Compile).value./("protobuf")
     ),
-    resolvers += Resolver.bintrayRepo("dhpcs", "maven"),
     testFrameworks := new TestFramework("utest.runner.Framework") :: Nil,
     fork in Test := true, // required for jni interrop with leveldb.
     buildInfoKeys := Seq[BuildInfoKey](
@@ -126,7 +135,7 @@ lazy val metaserver = project
       "org.scalameta" %% "semanticdb-scalac" % V.scalameta cross CrossVersion.full,
       "com.beachape" %% "enumeratum" % V.enumeratum,
       "com.lihaoyi" %% "utest" % "0.6.0" % Test,
-      "org.scalameta" %% "testkit" % V.scalameta % Test,
+      "org.scalameta" %% "testkit" % V.scalameta % Test
     )
   )
   .dependsOn(