Update to scala 2.13.1 (#481)

azure-pipelines.yml

@@ -17,7 +17,7 @@ trigger:
 pr: none
 
 variables:
-  graalVersion: 19.3.0 # Please ensure this is in sync with the graalAPIVersion in build.sbt
+  graalVersion: 19.3.1 # Please ensure this is in sync with the graalAPIVersion in build.sbt
   graalReleasesUrl: https://github.com/graalvm/graalvm-ce-builds/releases/download
   graalDistributionName: graalvm-ce-java8
   sbtVersion: 1.3.3    # Please ensure this is in sync with project/build.properties
@@ -167,4 +167,4 @@ jobs:
           echo "##vso[task.complete result=Failed;]DONE"
         condition: eq(variables['Agent.JobStatus'], 'SucceededWithIssues')
         displayName: Fail on Issues
-        
+

build.sbt

@@ -12,9 +12,9 @@ import sbtcrossproject.CrossPlugin.autoImport.{crossProject, CrossType}
 //// Global Configuration ////
 //////////////////////////////
 
-val scalacVersion = "2.12.10"
+val scalacVersion = "2.13.1"
-val graalVersion  = "19.3.0"
+val graalVersion  = "19.3.1"
-val circeVersion  = "0.12.3"
+val circeVersion  = "0.13.0"
 organization in ThisBuild := "org.enso"
 scalaVersion in ThisBuild := scalacVersion
 
@@ -25,8 +25,9 @@ Global / onChangedBuildSource := ReloadOnSourceChanges
 //////////////////////////
 
 javacOptions in ThisBuild ++= Seq(
-  "-encoding", // Provide explicit encoding (the next line)
+  "-encoding",   // Provide explicit encoding (the next line)
-  "UTF-8"      // Specify character encoding used by Java source files.
+  "UTF-8",       // Specify character encoding used by Java source files.
+  "-deprecation" // Shows a description of each use or override of a deprecated member or class.
 )
 
 scalacOptions in ThisBuild ++= Seq(
@@ -42,7 +43,6 @@ scalacOptions in ThisBuild ++= Seq(
   "-unchecked",                         // Enable additional warnings where generated code depends on assumptions.
   "-Xcheckinit",                        // Wrap field accessors to throw an exception on uninitialized access.
   "-Xlint:adapted-args",                // Warn if an argument list is modified to match the receiver.
-  "-Xlint:by-name-right-associative",   // By-name parameter of right associative operator.
   "-Xlint:constant",                    // Evaluation of a constant arithmetic expression results in an error.
   "-Xlint:delayedinit-select",          // Selecting member of DelayedInit.
   "-Xlint:doc-detached",                // A Scaladoc comment appears to be detached from its element.
@@ -56,29 +56,20 @@ scalacOptions in ThisBuild ++= Seq(
   "-Xlint:poly-implicit-overload",      // Parameterized overloaded implicit methods are not visible as view bounds.
   "-Xlint:private-shadow",              // A private field (or class parameter) shadows a superclass field.
   "-Xlint:stars-align",                 // Pattern sequence wildcard must align with sequence component.
-  "-Xlint:unsound-match",               // Pattern match may not be typesafe.
+  "-Xlint:type-parameter-shadow",       // A local type parameter shadows a type already in scope.
   "-Xmacro-settings:-logging@org.enso", // Disable the debug logging globally.
-  "-Yno-adapted-args",                  // Do not adapt an argument list (either by inserting () or creating a tuple) to match the receiver.
-  "-Ypartial-unification",              // Enable partial unification in type constructor inference
   "-Ywarn-dead-code",                   // Warn when dead code is identified.
   "-Ywarn-extra-implicit",              // Warn when more than one implicit parameter section is defined.
-  "-Ywarn-inaccessible",                // Warn about inaccessible types in method signatures.
-  "-Ywarn-infer-any",                   // Warn when a type argument is inferred to be `Any`.
-  "-Ywarn-nullary-override",            // Warn when non-nullary `def f()' overrides nullary `def f'.
-  "-Ywarn-nullary-unit",                // Warn when nullary methods return Unit.
   "-Ywarn-numeric-widen",               // Warn when numerics are widened.
   "-Ywarn-unused:imports",              // Warn if an import selector is not referenced.
+  "-Ywarn-unused:implicits",            // Warn if an implicit parameter is unused.
   "-Ywarn-unused:locals",               // Warn if a local definition is unused.
   "-Ywarn-unused:patvars",              // Warn if a variable bound in a pattern is unused.
   "-Ywarn-unused:privates",             // Warn if a private member is unused.
+  "-Ywarn-unused:params",               // Warn if a value parameter is unused.
   "-Ywarn-value-discard"                // Warn when non-Unit expression results are unused.
 )
 
-// ENABLE THIS IN Scala 2.13.1 (where import annotation.unused is available).
-//  "-Xlint:type-parameter-shadow",     // A local type parameter shadows a type already in scope.
-//  "-Ywarn-unused:implicits",          // Warn if an implicit parameter is unused.
-//  "-Ywarn-unused:params",             // Warn if a value parameter is unused.
-
 /////////////////////////////////
 //// Benchmark Configuration ////
 /////////////////////////////////
@@ -119,20 +110,22 @@ lazy val enso = (project in file("."))
 ////////////////////////////
 
 val monocle = {
-  val monocleVersion = "1.6.0"
+  val monocleVersion = "2.0.0"
   Seq(
     "com.github.julien-truffaut" %% "monocle-core"  % monocleVersion,
     "com.github.julien-truffaut" %% "monocle-macro" % monocleVersion,
     "com.github.julien-truffaut" %% "monocle-law"   % monocleVersion % "test"
   )
 }
+
+val catsVersion = "2.1.0"
 val cats = {
   Seq(
-    "org.typelevel" %% "cats-core"   % "2.0.0",
+    "org.typelevel" %% "cats-core"   % catsVersion,
-    "org.typelevel" %% "cats-effect" % "2.0.0",
+    "org.typelevel" %% "cats-effect" % catsVersion,
-    "org.typelevel" %% "cats-free"   % "2.0.0",
+    "org.typelevel" %% "cats-free"   % catsVersion,
-    "org.typelevel" %% "cats-macros" % "2.0.0",
+    "org.typelevel" %% "cats-macros" % catsVersion,
-    "org.typelevel" %% "kittens"     % "2.0.0"
+    "org.typelevel" %% "kittens"     % catsVersion
   )
 }
 
@@ -148,8 +141,8 @@ def akkaPkg(name: String)     = akkaURL %% s"akka-$name" % akkaVersion
 def akkaHTTPPkg(name: String) = akkaURL %% s"akka-$name" % akkaHTTPVersion
 
 val akkaURL          = "com.typesafe.akka"
-val akkaVersion      = "2.5.23"
+val akkaVersion      = "2.6.3"
-val akkaHTTPVersion  = "10.1.8"
+val akkaHTTPVersion  = "10.1.11"
 val akkaActor        = akkaPkg("actor")
 val akkaStream       = akkaPkg("stream")
 val akkaTyped        = akkaPkg("actor-typed")
@@ -196,12 +189,11 @@ lazy val flexer = crossProject(JVMPlatform, JSPlatform)
   .dependsOn(logger)
   .settings(
     version := "0.1",
-    scalacOptions -= "-deprecation", // FIXME
     resolvers += Resolver.sonatypeRepo("releases"),
     libraryDependencies ++= scala_compiler ++ Seq(
-      "org.feijoas"   %% "mango"      % "0.14",
+      "com.google.guava" % "guava"       % "28.2-jre",
-      "org.typelevel" %%% "cats-core" % "2.0.0-RC1",
+      "org.typelevel"    %%% "cats-core" % catsVersion,
-      "org.typelevel" %%% "kittens"   % "2.0.0"
+      "org.typelevel"    %%% "kittens"   % "2.0.0"
     )
   )
   .jsSettings(jsSettings)
@@ -220,9 +212,9 @@ lazy val syntax_definition = crossProject(JVMPlatform, JSPlatform)
   .dependsOn(logger, flexer)
   .settings(
     libraryDependencies ++= monocle ++ scala_compiler ++ Seq(
-      "org.typelevel" %%% "cats-core"     % "2.0.0-RC1",
+      "org.typelevel" %%% "cats-core"     % catsVersion,
       "org.typelevel" %%% "kittens"       % "2.0.0",
-      "com.lihaoyi"   %%% "scalatags"     % "0.7.0",
+      "com.lihaoyi"   %%% "scalatags"     % "0.8.5",
       "io.circe"      %%% "circe-core"    % circeVersion,
       "io.circe"      %%% "circe-generic" % circeVersion,
       "io.circe"      %%% "circe-parser"  % circeVersion
@@ -243,8 +235,8 @@ lazy val syntax = crossProject(JVMPlatform, JSPlatform)
     version := "0.1",
     logBuffered := false,
     libraryDependencies ++= Seq(
-      "org.scalatest" %%% "scalatest"     % "3.0.5" % Test,
+      "org.scalatest" %%% "scalatest"     % "3.1.0" % Test,
-      "com.lihaoyi"   %%% "pprint"        % "0.5.3",
+      "com.lihaoyi"   %%% "pprint"        % "0.5.9",
       "io.circe"      %%% "circe-core"    % circeVersion,
       "io.circe"      %%% "circe-generic" % circeVersion,
       "io.circe"      %%% "circe-parser"  % circeVersion
@@ -266,7 +258,7 @@ lazy val syntax = crossProject(JVMPlatform, JSPlatform)
     inConfig(Benchmark)(Defaults.testSettings),
     unmanagedSourceDirectories in Benchmark +=
     baseDirectory.value.getParentFile / "src/bench/scala",
-    libraryDependencies += "com.storm-enroute" %% "scalameter" % "0.17" % "bench",
+    libraryDependencies += "com.storm-enroute" %% "scalameter" % "0.19" % "bench",
     testFrameworks := List(
       new TestFramework("org.scalatest.tools.Framework"),
       new TestFramework("org.scalameter.ScalaMeterFramework")
@@ -292,16 +284,16 @@ lazy val graph = (project in file("common/graph/"))
   .configs(Test)
   .settings(
     version := "0.1",
-    scalacOptions -= "-deprecation", // FIXME
     resolvers ++= Seq(
       Resolver.sonatypeRepo("releases"),
       Resolver.sonatypeRepo("snapshots")
     ),
+    scalacOptions += "-Ymacro-annotations",
     libraryDependencies ++= scala_compiler ++ Seq(
       "com.chuusai"                %% "shapeless"    % "2.3.3",
       "io.estatico"                %% "newtype"      % "0.4.3",
-      "org.scalatest"              %% "scalatest"    % "3.2.0-SNAP10" % Test,
+      "org.scalatest"              %% "scalatest"    % "3.2.0-M2" % Test,
-      "org.scalacheck"             %% "scalacheck"   % "1.14.0" % Test,
+      "org.scalacheck"             %% "scalacheck"   % "1.14.3" % Test,
       "com.github.julien-truffaut" %% "monocle-core" % "2.0.0",
       "org.apache.commons"         % "commons-lang3" % "3.9"
     ),
@@ -314,10 +306,7 @@ lazy val graph = (project in file("common/graph/"))
     addCompilerPlugin(
       "org.typelevel" %% "kind-projector" % "0.11.0" cross CrossVersion.full
     ),
-    addCompilerPlugin (
+    addCompilerPlugin("io.tryp" % "splain" % "0.5.1" cross CrossVersion.patch),
-      "org.scalamacros" % "paradise" % "2.1.1" cross CrossVersion.full
-    ),
-    addCompilerPlugin("io.tryp" % "splain" % "0.5.0" cross CrossVersion.patch),
     scalacOptions ++= Seq(
       "-P:splain:infix:true",
       "-P:splain:foundreq:true",
@@ -331,7 +320,7 @@ lazy val pkg = (project in file("common/pkg"))
     mainClass in (Compile, run) := Some("org.enso.pkg.Main"),
     version := "0.1",
     libraryDependencies ++= circe ++ Seq(
-      "io.circe"   %% "circe-yaml" % "0.10.0", // separate from other circe deps because its independent project with its own versioning
+      "io.circe"   %% "circe-yaml" % "0.12.0", // separate from other circe deps because its independent project with its own versioning
       "commons-io" % "commons-io"  % "2.6"
     )
   )
@@ -344,10 +333,11 @@ lazy val file_manager = (project in file("common/file-manager"))
     libraryDependencies ++= akka,
     libraryDependencies += akkaSLF4J,
     libraryDependencies += "ch.qos.logback" % "logback-classic" % "1.2.3",
-    libraryDependencies += "org.scalatest"  %% "scalatest"      % "3.2.0-SNAP10" % Test,
+    libraryDependencies += "org.scalatest"  %% "scalatest"      % "3.2.0-M2" % Test,
-    libraryDependencies += "org.scalacheck" %% "scalacheck"     % "1.14.0" % Test,
+    libraryDependencies += "org.scalacheck" %% "scalacheck"     % "1.14.3" % Test,
     libraryDependencies += akkaTestkitTyped,
     libraryDependencies += "commons-io" % "commons-io"        % "2.6",
+    // upgrade blocked by gmethvin/directory-watcher#49
     libraryDependencies += "io.methvin" % "directory-watcher" % "0.9.6"
   )
 
@@ -357,8 +347,7 @@ lazy val project_manager = (project in file("common/project-manager"))
   )
   .settings(
     libraryDependencies ++= akka,
-    libraryDependencies ++= circe,
+    libraryDependencies ++= circe
-    libraryDependencies += "io.spray" %% "spray-json" % "1.3.5"
   )
   .dependsOn(pkg)
 
@@ -386,21 +375,44 @@ lazy val core_definition = (project in file("engine/core-definition"))
     inConfig(Benchmark)(Defaults.testSettings),
     parallelExecution in Test := false,
     logBuffered in Test := false,
+    scalacOptions += "-Ymacro-annotations",
     libraryDependencies ++= jmh ++ Seq(
       "com.chuusai"                %% "shapeless"    % "2.3.3",
-      "org.scalacheck"             %% "scalacheck"   % "1.14.0" % Test,
+      "org.scalacheck"             %% "scalacheck"   % "1.14.3" % Test,
-      "org.scalactic"              %% "scalactic"    % "3.0.8" % Test,
+      "org.scalactic"              %% "scalactic"    % "3.2.0-M2" % Test,
-      "org.scalatest"              %% "scalatest"    % "3.2.0-SNAP10" % Test,
+      "org.scalatest"              %% "scalatest"    % "3.2.0-M2" % Test,
-      "org.typelevel"              %% "cats-core"    % "2.0.0-M4",
+      "org.typelevel"              %% "cats-core"    % catsVersion,
       "com.github.julien-truffaut" %% "monocle-core" % "2.0.0"
     ),
     addCompilerPlugin(
-      "org.scalamacros" % "paradise" % "2.1.1" cross CrossVersion.full
+      "org.typelevel" %% "kind-projector" % "0.11.0" cross CrossVersion.full
+    )
+  )
+  .dependsOn(graph)
+  .dependsOn(syntax.jvm)
+
+lazy val polyglot_api = project
+  .in(file("engine/polyglot-api"))
+  .settings(
+    Test / fork := true,
+    Test / javaOptions ++= Seq(
+      // Puts the language runtime on the truffle classpath, rather than the
+      // standard classpath. This is the recommended way of handling this and
+      // we should strive to use such structure everywhere. See
+      // https://www.graalvm.org/docs/graalvm-as-a-platform/implement-language#graalvm
+      s"-Dtruffle.class.path.append=${(LocalProject("runtime") / Compile / fullClasspath).value
+        .map(_.data)
+        .mkString(File.pathSeparator)}"
+    ),
+    libraryDependencies ++= Seq(
+      "org.graalvm.sdk" % "polyglot-tck" % graalVersion   % "provided",
+      "org.scalatest"   %% "scalatest"   % "3.2.0-M2"     % Test,
+      "org.scalacheck"  %% "scalacheck"  % "1.14.3"       % Test
     ),
     addCompilerPlugin(
       "org.typelevel" %% "kind-projector" % "0.11.0" cross CrossVersion.full
     ),
-    addCompilerPlugin("io.tryp" % "splain" % "0.5.0" cross CrossVersion.patch),
+    addCompilerPlugin("io.tryp" % "splain" % "0.5.1" cross CrossVersion.patch),
     scalacOptions ++= Seq(
       "-P:splain:infix:true",
       "-P:splain:foundreq:true",
@@ -408,8 +420,41 @@ lazy val core_definition = (project in file("engine/core-definition"))
       "-P:splain:tree:true"
     )
   )
-  .dependsOn(graph)
+  .dependsOn(pkg)
-  .dependsOn(syntax.jvm)
+
+lazy val json_rpc_server = (project in file("engine/json-rpc-server"))
+  .settings(
+    libraryDependencies ++= akka ++ circe ++ Seq(
+      "io.circe"       %% "circe-generic-extras" % "0.12.2",
+      "io.circe"       %% "circe-literal" % circeVersion,
+      akkaTestkit      % Test,
+      "org.scalatest"  %% "scalatest" % "3.2.0-M2" % Test,
+      "org.scalacheck" %% "scalacheck" % "1.14.0" % Test
+    )
+  )
+
+lazy val language_server = (project in file("engine/language-server"))
+  .settings(
+    libraryDependencies ++= akka ++ Seq(
+      "org.graalvm.sdk" % "polyglot-tck" % graalVersion % Provided,
+      akkaTestkit       % Test,
+      "org.scalatest"   %% "scalatest"   % "3.2.0-M2"   % Test,
+      "org.scalacheck"  %% "scalacheck"  % "1.14.3"     % Test
+    )
+  )
+  .dependsOn(polyglot_api)
+
+lazy val gateway = (project in file("engine/gateway"))
+  .dependsOn(language_server)
+  .settings(
+    libraryDependencies ++= akka ++ circe ++ Seq(
+      "io.circe"       %% "circe-generic-extras" % "0.12.2",
+      "io.circe"       %% "circe-literal"        % circeVersion,
+      akkaTestkit      % Test,
+      "org.scalatest"  %% "scalatest"            % "3.2.0-M2" % Test,
+      "org.scalacheck" %% "scalacheck"           % "1.14.3" % Test
+    )
+  )
 
 lazy val runtime = (project in file("engine/runtime"))
   .configs(Benchmark)
@@ -420,21 +465,22 @@ lazy val runtime = (project in file("engine/runtime"))
     inConfig(Benchmark)(Defaults.testSettings),
     parallelExecution in Test := false,
     logBuffered in Test := false,
+    scalacOptions += "-Ymacro-annotations",
     libraryDependencies ++= jmh ++ Seq(
       "com.chuusai"         %% "shapeless"            % "2.3.3",
       "org.apache.commons"  % "commons-lang3"         % "3.9",
-      "org.apache.tika"     % "tika-core"             % "1.21",
+      "org.apache.tika"     % "tika-core"             % "1.23",
       "org.graalvm.sdk"     % "graal-sdk"             % graalVersion % "provided",
       "org.graalvm.sdk"     % "polyglot-tck"          % graalVersion % "provided",
       "org.graalvm.truffle" % "truffle-api"           % graalVersion % "provided",
       "org.graalvm.truffle" % "truffle-dsl-processor" % graalVersion % "provided",
       "org.graalvm.truffle" % "truffle-tck"           % graalVersion % "provided",
       "org.graalvm.truffle" % "truffle-tck-common"    % graalVersion % "provided",
-      "org.scalacheck"      %% "scalacheck"           % "1.14.0" % Test,
+      "org.scalacheck"      %% "scalacheck"           % "1.14.3" % Test,
-      "org.scalactic"       %% "scalactic"            % "3.0.8" % Test,
+      "org.scalactic"       %% "scalactic"            % "3.2.0-M2" % Test,
-      "org.scalatest"       %% "scalatest"            % "3.2.0-SNAP10" % Test,
+      "org.scalatest"       %% "scalatest"            % "3.2.0-M2" % Test,
       "org.graalvm.truffle" % "truffle-api"           % graalVersion % Benchmark,
-      "org.typelevel"       %% "cats-core"            % "2.0.0-M4"
+      "org.typelevel"       %% "cats-core"            % catsVersion
     ),
     // Note [Unmanaged Classpath]
     Compile / unmanagedClasspath += (core_definition / Compile / packageBin).value,
@@ -448,13 +494,10 @@ lazy val runtime = (project in file("engine/runtime"))
       "-s",
       (Compile / sourceManaged).value.getAbsolutePath
     ),
-    addCompilerPlugin(
-      "org.scalamacros" % "paradise" % "2.1.1" cross CrossVersion.full
-    ),
     addCompilerPlugin(
       "org.typelevel" %% "kind-projector" % "0.11.0" cross CrossVersion.full
     ),
-    addCompilerPlugin("io.tryp" % "splain" % "0.5.0" cross CrossVersion.patch),
+    addCompilerPlugin("io.tryp" % "splain" % "0.5.1" cross CrossVersion.patch),
     scalacOptions ++= Seq(
       "-P:splain:infix:true",
       "-P:splain:foundreq:true",
@@ -523,7 +566,7 @@ lazy val runner = project
       "org.graalvm.truffle"   % "truffle-api"            % graalVersion % "provided",
       "commons-cli"           % "commons-cli"            % "1.4",
       "io.github.spencerpark" % "jupyter-jvm-basekernel" % "2.3.0",
-      "org.jline"             % "jline"                  % "3.1.3"
+      "org.jline"             % "jline"                  % "3.13.3"
     ),
     connectInput in run := true
   )
@@ -546,58 +589,3 @@ lazy val runner = project
   .dependsOn(language_server)
   .dependsOn(gateway)
   .dependsOn(polyglot_api)
-
-lazy val gateway = (project in file("engine/gateway"))
-  .dependsOn(language_server)
-  .settings(
-    libraryDependencies ++= akka ++ circe ++ Seq(
-      "io.circe"       %% "circe-generic-extras" % "0.12.2",
-      "io.circe"       %% "circe-literal" % circeVersion,
-      akkaTestkit      % Test,
-      "org.scalatest"  %% "scalatest" % "3.2.0-SNAP10" % Test,
-      "org.scalacheck" %% "scalacheck" % "1.14.0" % Test
-    )
-  )
-
-lazy val json_rpc_server = (project in file("engine/json-rpc-server"))
-  .settings(
-    libraryDependencies ++= akka ++ circe ++ Seq(
-      "io.circe"       %% "circe-generic-extras" % "0.12.2",
-      "io.circe"       %% "circe-literal" % circeVersion,
-      akkaTestkit      % Test,
-      "org.scalatest"  %% "scalatest" % "3.2.0-SNAP10" % Test,
-      "org.scalacheck" %% "scalacheck" % "1.14.0" % Test
-    )
-  )
-
-lazy val language_server = (project in file("engine/language-server"))
-  .settings(
-    libraryDependencies ++= akka ++ Seq(
-      "org.graalvm.sdk" % "polyglot-tck" % graalVersion % Provided,
-      akkaTestkit       % Test,
-      "org.scalatest"   %% "scalatest" % "3.2.0-SNAP10" % Test,
-      "org.scalacheck"  %% "scalacheck" % "1.14.0" % Test
-    )
-  )
-  .dependsOn(polyglot_api)
-
-lazy val polyglot_api = project
-  .in(file("engine/polyglot-api"))
-  .settings(
-    Test / fork := true,
-    Test / javaOptions ++= Seq(
-      // Puts the language runtime on the truffle classpath, rather than the
-      // standard classpath. This is the recommended way of handling this and
-      // we should strive to use such structure everywhere. See
-      // https://www.graalvm.org/docs/graalvm-as-a-platform/implement-language#graalvm
-      s"-Dtruffle.class.path.append=${(LocalProject("runtime") / Compile / fullClasspath).value
-        .map(_.data)
-        .mkString(File.pathSeparator)}"
-    ),
-    libraryDependencies ++= Seq(
-      "org.graalvm.sdk" % "polyglot-tck" % graalVersion   % "provided",
-      "org.scalatest"   %% "scalatest"   % "3.2.0-SNAP10" % Test,
-      "org.scalacheck"  %% "scalacheck"  % "1.14.0"       % Test
-    )
-  )
-  .dependsOn(pkg)

common/file-manager/src/main/scala/org/enso/FileManager.scala

@@ -3,9 +3,9 @@ package org.enso
 import java.nio.file.Path
 import java.util.UUID
 
-import akka.actor.Scheduler
 import akka.actor.typed.ActorRef
 import akka.actor.typed.Behavior
+import akka.actor.typed.Scheduler
 import akka.actor.typed.scaladsl.AbstractBehavior
 import akka.actor.typed.scaladsl.ActorContext
 import akka.actor.typed.scaladsl.AskPattern.Askable
@@ -28,8 +28,8 @@ import scala.util.Try
   * [[org.enso.filemanager.API]] for a list of supported operations and their
   * respective request-response packages.
   */
-case class FileManager(projectRoot: Path, context: ActorContext[InputMessage])
+case class FileManager(projectRoot: Path, override val context: ActorContext[API.InputMessage])
-    extends AbstractBehavior[API.InputMessage] {
+    extends AbstractBehavior[API.InputMessage](context) {
 
   /** Active filesystem subtree watchers */
   val watchers: mutable.Map[UUID, DirectoryWatcher] = mutable.Map()

common/file-manager/src/main/scala/org/enso/filemanager/API.scala

@@ -40,7 +40,7 @@ object API {
     projectRoot: Path,
     accessedPath: Path)
       extends Exception(
-        s"""Cannot access path $accessedPath because it does not belong to 
+        s"""Cannot access path $accessedPath because it does not belong to
            |the project under root directory $projectRoot""".stripMargin
           .replaceAll("\n", " ")
       )
@@ -150,7 +150,7 @@ object API {
       override def handle(fileManager: FileManager): Response = {
         val str = Files.list(path)
         try {
-          Response(str.toArray.to[Vector].map(_.asInstanceOf[Path]))
+          Response(str.toArray.toVector.map(_.asInstanceOf[Path]))
         } finally str.close()
       }
     }

common/file-manager/src/test/scala/org/enso/filemanager/BehaviorTests.scala

@@ -11,15 +11,15 @@ import java.nio.file.Path
 import org.apache.commons.io.FileExistsException
 import org.enso.FileManager
 import org.enso.FileManager.API._
-import org.scalatest.FunSuite
-import org.scalatest.Matchers
 import org.scalatest.Outcome
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
 
 import scala.reflect.ClassTag
 import scala.util.Failure
 import scala.util.Success
 
-class BehaviorTests extends FunSuite with Matchers with Helpers {
+class BehaviorTests extends AnyFunSuite with Matchers with Helpers {
   var testKit: BehaviorTestKit[InputMessage] = _
   var inbox: TestInbox[OutputMessage]        = _
 

common/file-manager/src/test/scala/org/enso/filemanager/Helpers.scala

@@ -6,7 +6,7 @@ import java.nio.file.Paths
 
 import org.apache.commons.io.FileUtils
 
-import org.scalatest.Matchers
+import org.scalatest.matchers.should.Matchers
 
 trait Helpers extends Matchers {
   var tempDir: Path = _
@@ -71,15 +71,17 @@ trait Helpers extends Matchers {
     )
 
     val listStream = Files.list(subtree.root)
-    try listStream.count() should be(2)
+    try listStream.count() should be(2) : Unit
     finally listStream.close()
   }
 
   def expectExist(path: Path): Unit = {
     assert(Files.exists(path), s"$path is expected to exist")
+    ()
   }
 
   def expectNotExist(path: Path): Unit = {
     assert(!Files.exists(path), s"$path is expected to not exist")
+    ()
   }
 }

common/file-manager/src/test/scala/org/enso/filemanager/WatchTests.scala

@@ -1,9 +1,9 @@
 package org.enso.filemanager
 
-import akka.actor.Scheduler
 import akka.actor.testkit.typed.scaladsl.ActorTestKit
 import akka.actor.testkit.typed.scaladsl.TestProbe
 import akka.actor.typed.ActorRef
+import akka.actor.typed.Scheduler
 import akka.util.Timeout
 import io.methvin.watcher.DirectoryChangeEvent
 import java.nio.file.Files
@@ -14,9 +14,9 @@ import java.util.UUID
 import org.apache.commons.io.FileUtils
 import org.enso.FileManager
 import org.scalatest.BeforeAndAfterAll
-import org.scalatest.FunSuite
-import org.scalatest.Matchers
 import org.scalatest.Outcome
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
 
 import scala.concurrent.Await
 import scala.concurrent.Future
@@ -26,7 +26,7 @@ import scala.util.Try
 
 // needs to be separate because watcher message are asynchronous
 class WatchTests
-    extends FunSuite
+    extends AnyFunSuite
     with BeforeAndAfterAll
     with Matchers
     with Helpers {
@@ -49,11 +49,11 @@ class WatchTests
       try super.withFixture(test)
       finally if (watcherID != null)
         // Otherwise directory would stay blocked on Windows.
-        unobserve(watcherID)
+        unobserve(watcherID): Unit
     })
   }
 
-  override def afterAll() {
+  override def afterAll(): Unit = {
     testKit.shutdownTestKit()
   }
 
@@ -72,6 +72,7 @@ class WatchTests
       events.exists(matchesEvent(path, eventType)),
       s"not received message about $path"
     )
+    ()
   }
 
   def expectNextEvent(
@@ -84,6 +85,7 @@ class WatchTests
       matchesEvent(path, eventType)(message),
       s"expected of type $eventType for $path, got $message"
     )
+    ()
   }
 
   def ask[response <: Response.Success: ClassTag](
@@ -219,6 +221,6 @@ class WatchTests
       expectedOfType(DirectoryChangeEvent.EventType.DELETE)
 
       symlinkEventProbe.expectNoMessage(50.millis)
-    } finally unobserve(id)
+    } finally unobserve(id): Unit
   }
 }

common/flexer/src/main/scala/org/enso/flexer/Parser.scala

@@ -24,7 +24,7 @@ trait Parser[T] {
     reader.rewind.matched.set()
     reader.nextChar()
 
-    while (state.runCurrent() == State.Status.Exit.OK) Unit
+    while (state.runCurrent() == State.Status.Exit.OK) ()
 
     val value: Result.Value[T] = getResult() match {
       case None => Result.Failure(None)

common/flexer/src/main/scala/org/enso/flexer/automata/NFA.scala

@@ -9,6 +9,8 @@ final class NFA {
   val states: mutable.ArrayBuffer[State] = new mutable.ArrayBuffer()
   val vocabulary                         = new Dict()
 
+  import State.Implicits._
+
   //// API ////
 
   def addState(): Int = {
@@ -65,7 +67,7 @@ final class NFA {
   private def epsMatrix(): IndexedSeq[Set[Int]] = {
     val arr = new Array[EpsMatrix](states.size)
     states.indices.foreach(fillEpsMatrix(_, arr))
-    arr.map(_.links)
+    arr.toIndexedSeq.map(_.links)
   }
 
   private def nfaMatrix(): Array[Array[Int]] = {
@@ -74,7 +76,7 @@ final class NFA {
       for (stateIx <- states.indices) {
         val s = state(stateIx)
         for ((range, vocIx) <- vocabulary) {
-          s.links.ranged.get(range.start) match {
+          s.links.ranged.getOption(range.start) match {
             case Some(tgt) => matrix(stateIx)(vocIx) = tgt
             case None      => matrix(stateIx)(vocIx) = State.missing
           }
@@ -167,7 +169,7 @@ final class NFA {
       } else {
         lines += s"""$source"""
       }
-      for ((range, target) <- state.links.ranged.asMapOfRanges()) {
+      state.links.ranged.asMapOfRanges().forEach { (range, target) =>
         lines += s"""$source -> $target [label="$range"]"""
       }
       for (target <- state.links.epsilon) {

common/flexer/src/main/scala/org/enso/flexer/automata/State.scala

@@ -1,6 +1,6 @@
 package org.enso.flexer.automata
 
-import org.feijoas.mango.common.{collect => Guava}
+import com.google.common.{collect => guava}
 
 import scala.collection.mutable
 
@@ -10,23 +10,36 @@ class State {
 }
 
 object State {
+
+  object Implicits {
+
+    final implicit class RangeMapWrapper[K <: Comparable[_], V](underlying: guava.RangeMap[K, V]) {
+
+      def getOption(key: K): Option[V] =
+        Option(underlying.get(key))
+
+      def isEmpty: Boolean =
+        underlying.asMapOfRanges().isEmpty()
+    }
+  }
+
   val missing = -1
 
   case class Desc(priority: Int, rule: String)
 
   object Link {
+
     class Registry {
-      private type IntOrd = Ordering.Int.type
       val epsilon: mutable.ArrayBuffer[Int] = new mutable.ArrayBuffer()
-      val ranged: Guava.mutable.RangeMap[Int, Int, IntOrd] =
+      val ranged: guava.RangeMap[java.lang.Integer, Int] =
-        Guava.mutable.RangeMap()
+        guava.TreeRangeMap.create[java.lang.Integer, Int]()
 
       def add(target: Int): Unit =
         epsilon += target
 
       def add(target: Int, range: Range) =
         if (range.start <= range.end)
-          ranged.put(Guava.Range.closed(range.start, range.end), target)
+          ranged.put(guava.Range.closed(range.start, range.end), target)
     }
   }
 }

common/graph/src/main/scala/org/enso/graph/Graph.scala

@@ -495,7 +495,7 @@ object Graph {
     */
   final class GraphData[G <: Graph]()(implicit val info: GraphInfo[G]) {
     var components: Array[Component.Storage] =
-      this.componentSizes.map(size => new Component.Storage(size)).to[Array]
+      this.componentSizes.map(size => new Component.Storage(size)).toArray
 
     /** Gets a reference to the graph component at the specified index.
       *

common/graph/src/test/scala/org/enso/graph/ComponentMacroTest.scala

@@ -2,10 +2,11 @@ package org.enso.graph
 
 import org.enso.graph.{Graph => PrimGraph}
 import org.enso.graph.definition.Macro.component
-import org.scalatest.{FlatSpec, Matchers}
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 import shapeless.test.illTyped
 
-class ComponentMacroTest extends FlatSpec with Matchers {
+class ComponentMacroTest extends AnyFlatSpec with Matchers {
 
   "The `@component` macro" should "define correct components" in {
     "@component case class Edges() { type Edge[G <: Graph] }" should compile

common/graph/src/test/scala/org/enso/graph/FieldMacroTest.scala

@@ -2,10 +2,11 @@ package org.enso.graph
 
 import org.enso.graph.definition.Macro.{component, field, opaque}
 import org.enso.graph.{Graph => PrimGraph}
-import org.scalatest.{FlatSpec, Matchers}
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 import shapeless.test.illTyped
 
-class FieldMacroTest extends FlatSpec with Matchers {
+class FieldMacroTest extends AnyFlatSpec with Matchers {
 
   val subject = "The `@field` macro"
 

common/graph/src/test/scala/org/enso/graph/GraphTest.scala

@@ -1,11 +1,12 @@
 package org.enso.graph
 
 import org.enso.graph.{Graph => PrimGraph}
-import org.scalatest.{FlatSpec, Matchers}
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 import org.enso.graph.GraphTestDefinition._
 
 /** This file contains tests for the graph library. */
-class GraphTest extends FlatSpec with Matchers {
+class GraphTest extends AnyFlatSpec with Matchers {
 
   // ==========================================================================
   // === Example Graph Usage ==================================================
@@ -84,7 +85,6 @@ class GraphTest extends FlatSpec with Matchers {
     val typeResult = n1 match {
       case GraphImpl.Node.Shape.Nul.any(n @ _)  => "Null"
       case GraphImpl.Node.Shape.App.any(n1 @ _) => "App1"
-      case GraphImpl.Node.Shape.App(_, _)       => "App2"
     }
 
     typeResult shouldEqual "App1"

common/graph/src/test/scala/org/enso/graph/GraphTestDefinition.scala

@@ -4,6 +4,7 @@ import org.enso.graph.definition.Macro.{component, field, opaque}
 import org.enso.graph.{Graph => PrimGraph}
 import shapeless.{::, HNil}
 
+// import intentionally left unused
 import shapeless.nat._
 
 /** This file provides a small graph implementation for testing purposes.

common/graph/src/test/scala/org/enso/graph/OpaqueMacroTest.scala

@@ -1,12 +1,13 @@
 package org.enso.graph
 
 import org.enso.graph.definition.Macro.opaque
-import org.scalatest.{FlatSpec, Matchers}
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 import shapeless.test.illTyped
 
 import scala.collection.mutable
 
-class OpaqueMacroTest extends FlatSpec with Matchers {
+class OpaqueMacroTest extends AnyFlatSpec with Matchers {
   val subject = "The @opaque macro"
 
   subject should "define proper opaque maps" in {

common/graph/src/test/scala/org/enso/graph/TypeFunctionTest.scala

@@ -1,12 +1,13 @@
 package org.enso.graph
 
-import org.scalatest.{FlatSpec, Matchers}
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 import shapeless.{::, HNil, Nat}
 import shapeless.Nat._
 
 import scala.collection.mutable
 
-class TypeFunctionTest extends FlatSpec with Matchers {
+class TypeFunctionTest extends AnyFlatSpec with Matchers {
 
   object HListSumTest {
     implicitly[HListSum.Aux[HNil, _0]]
@@ -95,8 +96,8 @@ class TypeFunctionTest extends FlatSpec with Matchers {
 
     MapsOf.getOpaqueData[String, maps.Out](maps.instance) shouldEqual testMap
 
-    stringMap - 0
+    stringMap -= 0
-    testMap - 0
+    testMap -= 0
 
     MapsOf.getOpaqueData[String, maps.Out](maps.instance) shouldEqual testMap
   }

common/logger/src/main/scala/org/enso/Logger.scala

@@ -1,6 +1,5 @@
 package org.enso
 
-import scala.language.experimental.macros
 import scala.reflect.macros.blackbox.Context
 import org.enso.lint.Unused
 

common/parser-service/src/main/scala/org/enso/ParserService.scala

@@ -1,7 +1,5 @@
 package org.enso
 
-import io.circe.syntax._
-import io.circe.generic.auto._
 import org.enso.flexer.Reader
 import org.enso.parserservice.Protocol
 import org.enso.parserservice.Server

common/parser-service/src/main/scala/org/enso/parserservice/Server.scala

@@ -11,7 +11,6 @@ import akka.http.scaladsl.model.ws.BinaryMessage
 import akka.http.scaladsl.model.ws.Message
 import akka.http.scaladsl.model.ws.TextMessage
 import akka.http.scaladsl.model.ws.UpgradeToWebSocket
-import akka.stream.ActorMaterializer
 import akka.stream.scaladsl.Flow
 import akka.stream.scaladsl.Sink
 import akka.stream.scaladsl.Source
@@ -39,7 +38,6 @@ object Server {
   */
 trait Server {
   implicit val system: ActorSystem             = ActorSystem()
-  implicit val materializer: ActorMaterializer = ActorMaterializer()
 
   /** Generate text reply for given request text message. */
   def handleMessage(input: String): String

common/pkg/src/main/scala/org/enso/pkg/Package.scala

@@ -2,9 +2,9 @@ package org.enso.pkg
 
 import java.io.File
 import java.io.PrintWriter
-import java.nio.file.{Files, Path}
+import java.nio.file.Files
 
-import scala.collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 import org.apache.commons.io.FileUtils
 import org.enso.pkg.Package.qualifiedNameSeparator
 
@@ -46,7 +46,7 @@ case class Package(root: File, config: Config) {
   /**
     * Creates the package directory structure.
     */
-  def createDirectories() {
+  def createDirectories(): Unit = {
     val created = Try(root.mkdirs).getOrElse(false)
     if (!created) throw CouldNotCreateDirectory
     createSourceDir()

common/project-manager/src/main/scala/org/enso/projectmanager/Server.scala

@@ -3,14 +3,14 @@ package org.enso.projectmanager
 import java.io.File
 import java.util.concurrent.TimeUnit
 
-import akka.actor.{ActorSystem, Scheduler}
+import akka.actor.ActorSystem
 import akka.actor.typed.ActorRef
+import akka.actor.typed.Scheduler
 import akka.actor.typed.scaladsl.AskPattern._
 import akka.actor.typed.scaladsl.adapter._
 import akka.http.scaladsl.Http
 import akka.http.scaladsl.model.{HttpResponse, StatusCodes, Uri}
 import akka.http.scaladsl.server.{Directives, Route}
-import akka.stream.ActorMaterializer
 import akka.util.Timeout
 import com.typesafe.config.ConfigFactory
 import org.enso.projectmanager.api.{ProjectFactory, ProjectJsonSupport}
@@ -29,12 +29,11 @@ case class Server(
   apiFactory: ProjectFactory
 )(implicit val system: ActorSystem,
   implicit val executor: ExecutionContext,
-  implicit val materializer: ActorMaterializer,
   implicit val askTimeout: Timeout)
     extends Directives
     with ProjectJsonSupport {
 
-  implicit val scheduler: Scheduler = system.scheduler
+  implicit val scheduler: Scheduler = system.scheduler.toTyped
 
   def projectDoesNotExistResponse(id: ProjectId): HttpResponse =
     HttpResponse(StatusCodes.NotFound, entity = s"Project $id does not exist")
@@ -114,7 +113,7 @@ case class Server(
 
 object Server {
 
-  def main(args: Array[String]) {
+  def main(args: Array[String]): Unit = {
 
     val config        = ConfigFactory.load.getConfig("project-manager")
     val serverConfig  = config.getConfig("server")
@@ -131,7 +130,6 @@ object Server {
 
     implicit val system: ActorSystem             = ActorSystem("project-manager")
     implicit val executor: ExecutionContext      = system.dispatcher
-    implicit val materializer: ActorMaterializer = ActorMaterializer()
     implicit val askTimeout: Timeout             = new Timeout(timeout)
 
     val localProjectsPath =
@@ -165,6 +163,6 @@ object Server {
     val apiFactory  = ProjectFactory(routeHelper)
 
     val server = Server(host, port, repoActor, routeHelper, apiFactory)
-    server.serve
+    server.serve: Unit
   }
 }

common/project-manager/src/main/scala/org/enso/projectmanager/services/ProjectsService.scala

@@ -1,7 +1,7 @@
 package org.enso.projectmanager.services
 
 import akka.actor.typed.{ActorRef, Behavior}
-import akka.actor.typed.scaladsl.{Behaviors, StashBuffer}
+import akka.actor.typed.scaladsl.Behaviors
 import org.enso.projectmanager.model.{Project, ProjectId, ProjectsRepository}
 
 import scala.collection.immutable.HashMap
@@ -34,39 +34,40 @@ object ProjectsService {
     storageManager: StorageManager,
     tutorialsDownloader: TutorialsDownloader
   ): Behavior[ProjectsServiceCommand] = Behaviors.setup { context =>
-    val buffer = StashBuffer[ProjectsServiceCommand](capacity = 100)
+    Behaviors.withStash(capacity = 100) { buffer =>
 
-    def handle(
+      def handle(
-      localRepo: ProjectsRepository,
+        localRepo: ProjectsRepository,
-      tutorialsRepo: Option[ProjectsRepository]
+        tutorialsRepo: Option[ProjectsRepository]
-    ): Behavior[ProjectsServiceCommand] = Behaviors.receiveMessage {
+      ): Behavior[ProjectsServiceCommand] = Behaviors.receiveMessage {
-      case ListProjectsRequest(replyTo) =>
+        case ListProjectsRequest(replyTo) =>
-        replyTo ! ListProjectsResponse(localRepo.projects)
+          replyTo ! ListProjectsResponse(localRepo.projects)
-        Behaviors.same
+          Behaviors.same
-      case msg: ListTutorialsRequest =>
+        case msg: ListTutorialsRequest =>
-        tutorialsRepo match {
+          tutorialsRepo match {
-          case Some(repo) => msg.replyTo ! ListProjectsResponse(repo.projects)
+            case Some(repo) => msg.replyTo ! ListProjectsResponse(repo.projects)
-          case None       => buffer.stash(msg)
+            case None       => buffer.stash(msg)
-        }
+          }
-        Behaviors.same
+          Behaviors.same
-      case GetProjectById(id, replyTo) =>
+        case GetProjectById(id, replyTo) =>
-        val project =
+          val project =
-          localRepo.getById(id).orElse(tutorialsRepo.flatMap(_.getById(id)))
+            localRepo.getById(id).orElse(tutorialsRepo.flatMap(_.getById(id)))
-        replyTo ! GetProjectResponse(project)
+          replyTo ! GetProjectResponse(project)
-        Behaviors.same
+          Behaviors.same
-      case TutorialsReady =>
+        case TutorialsReady =>
-        val newTutorialsRepo = storageManager.readTutorials
+          val newTutorialsRepo = storageManager.readTutorials
-        buffer.unstashAll(context, handle(localRepo, Some(newTutorialsRepo)))
+          buffer.unstashAll(handle(localRepo, Some(newTutorialsRepo)))
-      case msg: CreateTemporary =>
+        case msg: CreateTemporary =>
-        val project =
+          val project =
-          storageManager.createTemporary(msg.name)
+            storageManager.createTemporary(msg.name)
-        val (projectId, newProjectsRepo) = localRepo.insert(project)
+          val (projectId, newProjectsRepo) = localRepo.insert(project)
-        msg.replyTo ! CreateTemporaryResponse(projectId, project)
+          msg.replyTo ! CreateTemporaryResponse(projectId, project)
-        handle(newProjectsRepo, tutorialsRepo)
+          handle(newProjectsRepo, tutorialsRepo)
+      }
+
+      context.pipeToSelf(tutorialsDownloader.run())(_ => TutorialsReady)
+
+      handle(storageManager.readLocalProjects, None)
     }
-
-    context.pipeToSelf(tutorialsDownloader.run())(_ => TutorialsReady)
-
-    handle(storageManager.readLocalProjects, None)
   }
 }

common/project-manager/src/main/scala/org/enso/projectmanager/services/TutorialsDownloader.scala

@@ -15,15 +15,14 @@ import akka.http.scaladsl.model.HttpResponse
 import akka.http.scaladsl.model.StatusCodes
 import akka.http.scaladsl.model.headers.Location
 import akka.http.scaladsl.unmarshalling.Unmarshal
-import akka.stream.ActorMaterializer
 import akka.stream.scaladsl.FileIO
 import org.apache.commons.io.IOUtils
 import spray.json.DefaultJsonProtocol
 import spray.json.JsonParser
 
-import scala.collection.JavaConverters._
 import scala.concurrent.ExecutionContext
 import scala.concurrent.Future
+import scala.jdk.CollectionConverters._
 import scala.util.Try
 
 case class GithubTutorial(name: String, lastPushString: String) {
@@ -37,8 +36,7 @@ trait GithubJsonProtocol extends SprayJsonSupport with DefaultJsonProtocol {
 
 case class HttpHelper()(
   implicit val executor: ExecutionContext,
-  implicit val system: ActorSystem,
+  implicit val system: ActorSystem) {
-  implicit val materializer: ActorMaterializer) {
 
   def performWithRedirects(request: HttpRequest): Future[HttpResponse] =
     Http().singleRequest(request).flatMap(followRedirects)
@@ -59,8 +57,7 @@ case class TutorialsDownloader(
   cacheDir: File,
   packagesGithubOrganisation: String
 )(implicit val system: ActorSystem,
-  implicit val executor: ExecutionContext,
+  implicit val executor: ExecutionContext)
-  implicit val materializer: ActorMaterializer)
     extends GithubJsonProtocol {
 
   val packagesGithubUrl =

common/syntax/definition/src/main/scala/org/enso/data/Tree.scala

@@ -14,7 +14,7 @@ final case class Tree[K, V](value: Option[V], branches: Map[K, Tree[K, V]]) {
   }
 
   def map[S](f: V => S): Tree[K, S] =
-    Tree(value.map(f), branches.mapValues(_.map(f)))
+    Tree(value.map(f), branches.view.mapValues(_.map(f)).toMap)
 
   def dropValues(): Tree[K, Unit] =
     map(_ => ())

common/syntax/definition/src/main/scala/org/enso/syntax/text/AST.scala

@@ -917,7 +917,7 @@ object Shape extends ShapeImplicit {
       R + symbol + symbol + _.lines.mkString("\n")
     // FIXME: How to make it automatic for non-spaced AST?
     implicit def ozip[T]: OffsetZip[Comment, T] = _.map(Index.Start -> _)
-    implicit def span[T]: HasSpan[Comment[T]]   = t => 0
+    implicit def span[T]: HasSpan[Comment[T]]   = _ => 0
   }
 
   object Documented {
@@ -932,7 +932,7 @@ object Shape extends ShapeImplicit {
     }
     implicit def offsetZip[T]: OffsetZip[Documented, T] =
       _.map(Index.Start -> _)
-    implicit def span[T: HasSpan]: HasSpan[Documented[T]] = t => 0
+    implicit def span[T: HasSpan]: HasSpan[Documented[T]] = _ => 0
 
     implicit def toJson[T]: Encoder[Documented[T]] =
       _ => throw new NotImplementedError()
@@ -946,7 +946,7 @@ object Shape extends ShapeImplicit {
 
     // FIXME: How to make it automatic for non-spaced AST?
     implicit def ozip[T]: OffsetZip[Import, T] = _.map(Index.Start -> _)
-    implicit def span[T]: HasSpan[Import[T]]   = t => 0
+    implicit def span[T]: HasSpan[Import[T]]   = _ => 0
   }
 
   object Mixfix {
@@ -956,11 +956,11 @@ object Shape extends ShapeImplicit {
       val lastRepr = if (t.name.length == t.args.length) List() else List(R)
       val argsRepr = t.args.toList.map(R + " " + _) ++ lastRepr
       val nameRepr = t.name.toList.map(Repr(_))
-      R + (nameRepr, argsRepr).zipped.map(_ + _)
+      R + nameRepr.lazyZip(argsRepr).map(_ + _)
     }
     // FIXME: How to make it automatic for non-spaced AST?
     implicit def ozip[T]: OffsetZip[Mixfix, T] = _.map(Index.Start -> _)
-    implicit def span[T]: HasSpan[Mixfix[T]]   = t => 0
+    implicit def span[T]: HasSpan[Mixfix[T]]   = _ => 0
   }
 
   object Group {
@@ -970,7 +970,7 @@ object Shape extends ShapeImplicit {
       R + "(" + _.body + ")"
     // FIXME: How to make it automatic for non-spaced AST?
     implicit def ozip[T]: OffsetZip[Group, T] = _.map(Index.Start -> _)
-    implicit def span[T]: HasSpan[Group[T]]   = t => 0
+    implicit def span[T]: HasSpan[Group[T]]   = _ => 0
   }
 
   object Def {
@@ -980,7 +980,7 @@ object Shape extends ShapeImplicit {
       t => R + Def.symbol + 1 + t.name + t.args.map(R + 1 + _) + t.body
     // FIXME: How to make it automatic for non-spaced AST?
     implicit def ozip[T]: OffsetZip[Def, T] = _.map(Index.Start -> _)
-    implicit def span[T]: HasSpan[Def[T]]   = t => 0
+    implicit def span[T]: HasSpan[Def[T]]   = _ => 0
 
     val symbol = "def"
   }
@@ -994,7 +994,7 @@ object Shape extends ShapeImplicit {
     }
     // FIXME: How to make it automatic for non-spaced AST?
     implicit def ozip[T]: OffsetZip[Foreign, T] = _.map(Index.Start -> _)
-    implicit def span[T]: HasSpan[Foreign[T]]   = t => 0
+    implicit def span[T]: HasSpan[Foreign[T]]   = _ => 0
   }
   //// Implicits ////
 
@@ -1480,7 +1480,7 @@ object AST {
       import io.circe.generic.auto._
 
       // Note (below) [JSON Format Customizations]
-      implicit def blockEncoder[T: Encoder]: Encoder[Shape.Block[T]] =
+      implicit def blockEncoder[A: Encoder]: Encoder[Shape.Block[A]] =
         block =>
           Json.obj(
             "ty"          -> block.ty.asJson,
@@ -1721,10 +1721,10 @@ object AST {
         def unapply(t: AST) =
           Unapply[Unclosed].run(t => t.line)(t)
         def apply(segment: Segment.Fmt*): Unclosed =
-          Shape.TextUnclosed(Line.Fmt(segment.to[List]))
+          Shape.TextUnclosed(Line.Fmt(segment.toList))
         object Raw {
           def apply(segment: Segment.Raw*): Unclosed =
-            Shape.TextUnclosed(Line.Raw(segment.to[List]))
+            Shape.TextUnclosed(Line.Raw(segment.toList))
         }
       }
       type InvalidQuote = ASTOf[Shape.InvalidQuote]
@@ -1743,23 +1743,23 @@ object AST {
       }
 
       def apply(text: Shape.Text[AST]): Text = text
-      def apply(segment: Segment.Fmt*): Text = Text(Line.Fmt(segment.to[List]))
+      def apply(segment: Segment.Fmt*): Text = Text(Line.Fmt(segment.toList))
       def apply(
         spaces: Int,
         off: Int,
         line: Shape.TextBlockLine[Segment.Fmt]*
       ): Text =
-        Text(Shape.TextBlockFmt(line.to[List], spaces, off))
+        Text(Shape.TextBlockFmt(line.toList, spaces, off))
 
       object Raw {
         def apply(segment: Segment.Raw*): Text =
-          Text(Line.Raw(segment.to[List]))
+          Text(Line.Raw(segment.toList))
         def apply(
           spaces: Int,
           off: Int,
           line: Shape.TextBlockLine[Segment.Raw]*
         ): Text =
-          Text(Shape.TextBlockRaw(line.to[List], spaces, off))
+          Text(Shape.TextBlockRaw(line.toList, spaces, off))
       }
 
       /////////////////
@@ -1941,7 +1941,7 @@ object AST {
       indent,
       List(),
       Line(firstLine),
-      lines.to[List].map(ast => Line(Some(ast)))
+      lines.toList.map(ast => Line(Some(ast)))
     )
 
     val any = UnapplyByType[Block]
@@ -1979,7 +1979,7 @@ object AST {
     def unapply(t: AST)                         = Unapply[M].run(_.lines)(t)
     def apply(ls: List1[OptLine]): M            = Shape.Module(ls)
     def apply(l: OptLine): M                    = Module(List1(l))
-    def apply(l: OptLine, ls: OptLine*): M      = Module(List1(l, ls.to[List]))
+    def apply(l: OptLine, ls: OptLine*): M      = Module(List1(l, ls.toList))
     def apply(l: OptLine, ls: List[OptLine]): M = Module(List1(l, ls))
     def traverseWithOff(m: M)(f: (Index, AST) => AST): M = {
       val lines2 = m.lines.map { line: OptLine =>
@@ -2297,9 +2297,9 @@ object AST {
     val any = UnapplyByType[Foreign]
   }
 
-  def main() {
+  def main(): Unit = {
     val v1  = Ident.Var("foo")
-    val v1_ = v1: AST
+    //    val v1_ = v1: AST
 
     println(v1.span)
     println((v1: AST.Ident).span)
@@ -2308,7 +2308,7 @@ object AST {
     //    println(v1_.asJson)
     //    val opr1 = Ident.Opr("+")
     val v2  = App.Prefix(Ident.Var("x"), 10, Ident.Var("z"))
-    val v2_ = v2: AST
+    //    val v2_ = v2: AST
     //
     //    println(v2.asJson)
     //    println(v2_.asJson)

common/syntax/definition/src/main/scala/org/enso/syntax/text/ast/Repr2.scala

@@ -160,7 +160,7 @@ object Repr {
         })
     }
 
-    def Empty()                     = Builder(0, identity(_))
+    def Empty()                     = Builder(0, identity(_): Unit)
     def Space(span: Int)            = Builder(span, _ ++= (" " * span))
     def Letter(char: Char)          = Builder(1, _ += char)
     def Text(str: String)           = Builder(str.length, _ ++= str)

common/syntax/definition/src/main/scala/org/enso/syntax/text/ast/meta/Pattern.scala

@@ -1,7 +1,6 @@
 package org.enso.syntax.text.ast.meta
 
 import org.enso.syntax.text.{AST, HasSpan, OffsetZip}
-import org.enso.syntax.text.HasSpan.implicits._
 import org.enso.syntax.text.AST.SAST
 import org.enso.syntax.text.prec.Operator
 import org.enso.syntax.text.ast.Repr

common/syntax/definition/src/main/scala/org/enso/syntax/text/ast/text/Escape.scala

@@ -1,7 +1,6 @@
 package org.enso.syntax.text.ast.text
 
 import org.enso.flexer.ADT
-import org.enso.syntax.text.ast.text.Escape.Slash.toString
 
 sealed trait Escape {
   val repr: String

common/syntax/definition/src/main/scala/org/enso/syntax/text/spec/DocParserDef.scala

@@ -125,7 +125,7 @@ case class DocParserDef() extends Parser[Doc] {
           if (details.nonEmpty) {
             var det = text.removeWhitespaces(details)
             if (tagType != Tags.Tag.Unrecognized) {
-              det = ' ' + det
+              det = s" $det"
             }
             stack +:= Tags.Tag(indent, tagType, Some(det))
           } else {

common/syntax/specialization/shared/src/main/scala/org/enso/syntax/text/DocParser.scala

@@ -305,7 +305,7 @@ object DocParserHTMLGenerator {
           generateHTMLForEveryDocumented(elem, path, cssFileName)
       }
       elem
-    }
+    } : Unit
   }
 
   //////////////////////////////////////////////////////////////////////////////

common/syntax/specialization/shared/src/main/scala/org/enso/syntax/text/Parser.scala

@@ -2,16 +2,14 @@ package org.enso.syntax.text
 
 import java.util.UUID
 
-import cats.{Foldable, Monoid}
+import cats.Foldable
-import org.enso.data.{Index, List1, Shifted, Span}
+import org.enso.data.{List1, Span}
 import org.enso.flexer
 import org.enso.flexer.Reader
 import org.enso.syntax.text.AST.Block.{Line, OptLine}
 import org.enso.syntax.text.AST.Macro.Match.SegmentOps
-import org.enso.syntax.text.AST.{App, Module}
+import org.enso.syntax.text.AST.App
 import org.enso.syntax.text.ast.meta.Builtin
-import org.enso.syntax.text.ast.opr.Prec
-import org.enso.syntax.text.prec.Distance
 import org.enso.syntax.text.prec.Macro
 import org.enso.syntax.text.spec.ParserDef
 import cats.implicits._
@@ -398,24 +396,24 @@ object Main extends scala.App {
       |  UPCOMING
       |  ALAMAKOTA a kot ma Ale
       |  This is a test of Enso Documentation Parser. This is a short synopsis.
-      | 
+      |
       |  Here you can write the body of documentation. On top you can see tags
       |  added to this piece of code. You can customise your text with _Italic_
       |  ~Strikethrough~ or *Bold*. ~_*Combined*_~ is funny
-      |  
+      |
-      |  
+      |
       |  There are 3 kinds of sections
       |    - Important
       |    - Info
       |    - Example
       |      * You can use example to add multiline code to your documentation
-      | 
+      |
       |  ! Important
       |    Here is a small test of Important Section
-      |    
+      |
       |  ? Info
       |    Here is a small test of Info Section
-      |    
+      |
       |  > Example
       |    Here is a small test of Example Section
       |        Import Foo
@@ -426,7 +424,7 @@ object Main extends scala.App {
       |    ##DEPRECATED
       |      foo bar baz
       |    type Nothing
-      |    
+      |
       |    ## The pow function calculates power of integers.
       |    pow x y = x ** y
       |""".stripMargin
@@ -461,7 +459,7 @@ object Main extends scala.App {
       |     Also, `None` is the return value of functions which do not return an
       |     explicit value.
       |    type None
-      |    
+      |
       |    ## The pow function calculates power of integers.
       |    pow x y = x ** y
       |""".stripMargin

common/syntax/specialization/shared/src/test/scala/org/enso/syntax/text/DocParserTests.scala

@@ -7,11 +7,11 @@ import org.enso.Logger
 import org.enso.flexer.Parser.Result
 import org.enso.flexer.Reader
 import org.enso.syntax.text.ast.Doc.Tags.Tag
-import org.scalatest.FlatSpec
-import org.scalatest.Matchers
 import org.scalatest.Assertion
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 
-class DocParserTests extends FlatSpec with Matchers {
+class DocParserTests extends AnyFlatSpec with Matchers {
   val logger = new Logger()
 
   def assertExpr(input: String, result: Doc): Assertion = {

common/syntax/specialization/shared/src/test/scala/org/enso/syntax/text/ParserTest.scala

@@ -9,8 +9,10 @@ import org.enso.syntax.text.AST._
 import org.enso.syntax.text.AST.conversions._
 import org.enso.syntax.text.ast.DSL._
 import org.scalatest._
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 
-class ParserTest extends FlatSpec with Matchers {
+class ParserTest extends AnyFlatSpec with Matchers {
 
   def assertSpan(input: String, ast: AST): Assertion = {
     val gotSpan      = ast.span
@@ -65,7 +67,7 @@ class ParserTest extends FlatSpec with Matchers {
 
     def ?=(out: AST) = testBase in { assertExpr(input, out) }
     def ??=(out: Module) = testBase in { assertModule(input, out) }
-    def testIdentity     = testBase in { assertIdentity(input)    }
+    def testIdentity()   = testBase in { assertIdentity(input)    }
   }
 
   //////////////////////////////////////////////////////////////////////////////
@@ -181,9 +183,9 @@ class ParserTest extends FlatSpec with Matchers {
 
   import Shape.SegmentPlain.txtFromString
   def line(s: String, empty: Int*) =
-    Shape.TextBlockLine(empty.to[List], List(txtFromString[AST](s)))
+    Shape.TextBlockLine(empty.toList, List(txtFromString[AST](s)))
   def line(segment: AST.Text.Segment.Fmt, empty: Int*) =
-    Shape.TextBlockLine(empty.to[List], List(segment))
+     Shape.TextBlockLine(empty.toList, List(segment))
 
   "'"    ?= Text.Unclosed()
   "''"   ?= Text()
@@ -398,20 +400,20 @@ class ParserTest extends FlatSpec with Matchers {
   //// Large Input /////////////////////////////////////////////////////////////
   //////////////////////////////////////////////////////////////////////////////
 
-//  ("(" * 33000).testIdentity // FIXME Stack Overflow
+//  ("(" * 33000).testIdentity() // FIXME Stack Overflow
-//  ("OVERFLOW " * 5000).testIdentity
+//  ("OVERFLOW " * 5000).testIdentity()
-//  ("\uD800\uDF1E " * 10000).testIdentity
+//  ("\uD800\uDF1E " * 10000).testIdentity()
 
   //////////////////////////////////////////////////////////////////////////////
   //// OTHER (TO BE PARTITIONED)////////////////////////////////////////////////
   //////////////////////////////////////////////////////////////////////////////
 
-  "\na \nb \n".testIdentity
+  "\na \nb \n".testIdentity()
-  "f =  \n\n\n".testIdentity
+  "f =  \n\n\n".testIdentity()
-  "  \n\n\n f\nf".testIdentity
+  "  \n\n\n f\nf".testIdentity()
-  "f =  \n\n  x ".testIdentity
+  "f =  \n\n  x ".testIdentity()
-  "  a\n   b\n  c".testIdentity
+  "  a\n   b\n  c".testIdentity()
-  "f =\n\n  x\n\n y".testIdentity
+  "f =\n\n  x\n\n y".testIdentity()
 
   """
     a
@@ -420,7 +422,7 @@ class ParserTest extends FlatSpec with Matchers {
     d
   e
    f g h
-  """.testIdentity
+  """.testIdentity()
 
   """
   # adults: old population
@@ -438,7 +440,7 @@ class ParserTest extends FlatSpec with Matchers {
     isUnique xs i ####
       = xs.at(i).score != xs.at(i-1).score
     adults++children++mutants . sorted . unique . take (length pop1) . pure
-  """.testIdentity
+  """.testIdentity()
 
   ///////////////////////
   //// Preprocessing ////

engine/gateway/src/main/scala/org/enso/gateway/Server.scala

@@ -7,7 +7,6 @@ import akka.http.scaladsl.Http
 import akka.http.scaladsl.model.ws.{BinaryMessage, Message, TextMessage}
 import akka.http.scaladsl.server.Directives._
 import akka.http.scaladsl.server.Route
-import akka.stream.ActorMaterializer
 import akka.stream.scaladsl.Flow
 import akka.stream.scaladsl.Sink
 import akka.stream.scaladsl.Source
@@ -32,9 +31,7 @@ import scala.util.Success
   * @param config            Server config.
   */
 class Server(jsonRpcController: JsonRpcController, config: Config)(
-  implicit
+  implicit system: ActorSystem
-  system: ActorSystem,
-  materializer: ActorMaterializer
 ) {
   import system.dispatcher
 
@@ -57,7 +54,7 @@ class Server(jsonRpcController: JsonRpcController, config: Config)(
             .flatMapConcat(
               input =>
                 Source
-                  .fromFuture(
+                  .future(
                     jsonRpcController.getTextOutput(input)
                   )
             )

engine/gateway/src/test/scala/org/enso/gateway/GatewayJsonSpec.scala

@@ -4,25 +4,20 @@ import akka.NotUsed
 import akka.actor.{ActorRef, ActorSystem}
 import akka.http.scaladsl.Http
 import akka.http.scaladsl.model.ws.{Message, TextMessage, WebSocketRequest}
-import akka.stream.ActorMaterializer
 import akka.stream.scaladsl.{Flow, Keep, Sink, Source}
 import io.circe.Json
+import io.circe.parser.parse
+import org.enso.{Gateway, LanguageServer}
 import org.enso.gateway.TestJson.{
   Initialize,
   Shutdown,
   WrongJsonrpc,
   WrongMethod
 }
-import org.enso.{Gateway, LanguageServer}
-import org.scalatest.{
-  Assertion,
-  AsyncFlatSpec,
-  BeforeAndAfterAll,
-  GivenWhenThen,
-  Matchers
-}
-import io.circe.parser.parse
 import org.enso.gateway.server.Config
+import org.scalatest.{Assertion, BeforeAndAfterAll, GivenWhenThen}
+import org.scalatest.flatspec.AsyncFlatSpec
+import org.scalatest.matchers.should.Matchers
 
 import scala.concurrent.{Await, Future}
 import scala.concurrent.duration._
@@ -33,8 +28,6 @@ class GatewayJsonSpec
     with BeforeAndAfterAll
     with GivenWhenThen {
   implicit private val system: ActorSystem = ActorSystem()
-  implicit private val materializer: ActorMaterializer =
-    ActorMaterializer.create(system)
 
   import system.dispatcher
 

engine/gateway/src/test/scala/org/enso/gateway/GatewayMessageSpec.scala

@@ -3,14 +3,16 @@ package org.enso.gateway
 import akka.actor.{ActorRef, ActorSystem}
 import akka.testkit.{ImplicitSender, TestKit}
 import org.enso.{Gateway, LanguageServer}
-import org.scalatest.{BeforeAndAfterAll, Matchers, WordSpecLike}
 import org.enso.gateway.TestMessage.{Initialize, Shutdown}
 import org.enso.gateway.TestNotification.{Exit, Initialized}
+import org.scalatest.BeforeAndAfterAll
+import org.scalatest.matchers.should.Matchers
+import org.scalatest.wordspec.AnyWordSpecLike
 
 class GatewayMessageSpec()
     extends TestKit(ActorSystem("GatewayMessageSpec"))
     with ImplicitSender
-    with WordSpecLike
+    with AnyWordSpecLike
     with Matchers
     with BeforeAndAfterAll {
 

engine/json-rpc-server/src/test/scala/org/enso/jsonrpcserver/MessageHandlerTest.scala

@@ -2,7 +2,9 @@ package org.enso.jsonrpcserver
 import akka.actor.{ActorRef, ActorSystem, Props}
 import akka.testkit.{ImplicitSender, TestKit, TestProbe}
 import io.circe.{Decoder, Encoder, Json}
-import org.scalatest.{BeforeAndAfterAll, Matchers, WordSpecLike}
+import org.scalatest.EitherValues
+import org.scalatest.matchers.should.Matchers
+import org.scalatest.wordspec.AnyWordSpecLike
 
 import scala.concurrent.duration._
 import io.circe.parser._
@@ -12,7 +14,7 @@ import org.enso.jsonrpcserver.MessageHandler.{Connected, WebMessage}
 class MessageHandlerTest
     extends TestKit(ActorSystem("TestSystem"))
     with ImplicitSender
-    with WordSpecLike
+    with AnyWordSpecLike
     with Matchers
     with BeforeAndAfterAll {
 
@@ -240,7 +242,7 @@ class MessageHandlerTest
     msg shouldBe an[WebMessage]
     val contents  = msg.asInstanceOf[WebMessage].message
     val maybeJson = parse(contents)
-    maybeJson shouldBe 'right
+    maybeJson shouldBe Symbol("right")
-    maybeJson.right.get shouldEqual expectedJson
+    maybeJson.foreach(_ shouldEqual expectedJson)
   }
 }

engine/language-server/src/test/scala/org/enso/languageserver/LanguageServerSpec.scala

@@ -5,12 +5,14 @@ import akka.testkit.{ImplicitSender, TestKit, TestProbe}
 import org.enso.LanguageServer
 import org.enso.languageserver.Notifications.{Exit, Initialized}
 import org.enso.languageserver.Requests.{Initialize, Shutdown}
-import org.scalatest.{BeforeAndAfterAll, Matchers, WordSpecLike}
+import org.scalatest.BeforeAndAfterAll
+import org.scalatest.matchers.should.Matchers
+import org.scalatest.wordspec.AnyWordSpecLike
 
 class LanguageServerSpec()
     extends TestKit(ActorSystem("LanguageServerSpec"))
     with ImplicitSender
-    with WordSpecLike
+    with AnyWordSpecLike
     with Matchers
     with BeforeAndAfterAll {
 

engine/polyglot-api/src/main/scala/org/enso/polyglot/Module.scala

@@ -1,7 +1,5 @@
 package org.enso.polyglot
 
-import java.io.File
-
 import org.graalvm.polyglot.Value
 
 /**
@@ -45,7 +43,7 @@ class Module(private val value: Value) {
     * @param additionalSource the new source to parse
     */
   def patch(additionalSource: String): Unit =
-    value.invokeMember(PATCH, additionalSource)
+    value.invokeMember(PATCH, additionalSource): Unit
 
   /**
     * Evaluates an arbitrary expression as if it were placed in a function
@@ -60,13 +58,15 @@ class Module(private val value: Value) {
     * Triggers reparsing of module sources. Used to notify the module that
     * sources have changed.
     */
-  def reparse(): Unit = { value.invokeMember(REPARSE) }
+  def reparse(): Unit = {
+    value.invokeMember(REPARSE): Unit
+  }
 
   def setSource(source: String): Unit = {
-    value.invokeMember(SET_SOURCE, source)
+    value.invokeMember(SET_SOURCE, source): Unit
   }
 
   def setSourceFile(file: String): Unit = {
-    value.invokeMember(SET_SOURCE_FILE, file)
+    value.invokeMember(SET_SOURCE_FILE, file): Unit
   }
 }

engine/polyglot-api/src/main/scala/org/enso/polyglot/TopScope.scala

@@ -1,6 +1,6 @@
 package org.enso.polyglot
 
-import org.graalvm.polyglot.{Context, Value}
+import org.graalvm.polyglot.Value
 
 /**
   * Represents the top scope of Enso execution context
@@ -33,6 +33,6 @@ class TopScope(private val value: Value) {
     new Module(value.invokeMember(REGISTER_MODULE, qualifiedName, filePath))
 
   def unregisterModule(qualifiedName: String): Unit = {
-    value.invokeMember(UNREGISTER_MODULE, qualifiedName)
+    value.invokeMember(UNREGISTER_MODULE, qualifiedName): Unit
   }
 }

engine/polyglot-api/src/test/scala/org/enso/polyglot/ApiTest.scala

@@ -1,8 +1,10 @@
 package org.enso.polyglot
-import org.graalvm.polyglot.Context
-import org.scalatest.{FlatSpec, Matchers}
 
-class ApiTest extends FlatSpec with Matchers {
+import org.graalvm.polyglot.Context
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+
+class ApiTest extends AnyFlatSpec with Matchers {
   import LanguageInfo._
   val executionContext = new ExecutionContext(Context.newBuilder(ID).build())
 

engine/polyglot-api/src/test/scala/org/enso/polyglot/ModuleManagementTest.scala

@@ -1,14 +1,14 @@
 package org.enso.polyglot
+
 import java.io.File
 import java.nio.file.Files
 
+import org.enso.pkg.Package
 import org.graalvm.polyglot.{Context, PolyglotException}
-import org.scalatest.{FlatSpec, Matchers}
+import org.scalatest.flatspec.AnyFlatSpec
-import org.enso.pkg.{Package, QualifiedName}
+import org.scalatest.matchers.should.Matchers
 
-import scala.util.Try
+class ModuleManagementTest extends AnyFlatSpec with Matchers {
-
-class ModuleManagementTest extends FlatSpec with Matchers {
   class TestContext(packageName: String) {
     val tmpDir: File = Files.createTempDirectory("enso-test-packages").toFile
     val pkg: Package = Package.create(tmpDir, packageName)
@@ -24,11 +24,11 @@ class ModuleManagementTest extends FlatSpec with Matchers {
     def mkFile(name: String): File = new File(tmpDir, name)
 
     def writeFile(name: String, contents: String): Unit = {
-      Files.write(mkFile(name).toPath, contents.getBytes)
+      Files.write(mkFile(name).toPath, contents.getBytes): Unit
     }
 
     def writeMain(contents: String): Unit = {
-      Files.write(pkg.mainFile.toPath, contents.getBytes)
+      Files.write(pkg.mainFile.toPath, contents.getBytes): Unit
     }
   }
 

engine/runner/src/main/scala/org/enso/runner/ContextFactory.scala

@@ -3,7 +3,6 @@ package org.enso.runner
 import java.io.InputStream
 import java.io.OutputStream
 
-import org.enso.interpreter.Constants
 import org.enso.interpreter.instrument.ReplDebuggerInstrument
 import org.enso.polyglot.{ExecutionContext, LanguageInfo, RuntimeOptions}
 import org.graalvm.polyglot.Context

engine/runner/src/main/scala/org/enso/runner/JupyterKernel.scala

@@ -11,8 +11,8 @@ import io.github.spencerpark.jupyter.kernel.KernelConnectionProperties
 import io.github.spencerpark.jupyter.kernel
 import io.github.spencerpark.jupyter.kernel.display.DisplayData
 import org.enso.polyglot
-import org.enso.polyglot.{ExecutionContext, LanguageInfo, Module, TopScope}
+import org.enso.polyglot.{ExecutionContext, LanguageInfo, Module}
-import org.graalvm.polyglot.{Context, Value}
+import org.graalvm.polyglot.Value
 
 /**
   * A wrapper for Enso interpreter for use by Jupyter

engine/runner/src/main/scala/org/enso/runner/Main.scala

@@ -9,7 +9,6 @@ import org.enso
 import org.enso.polyglot.{ExecutionContext, LanguageInfo, Module}
 import org.enso.{Gateway, LanguageServer}
 import akka.actor.{ActorRef, ActorSystem}
-import akka.stream.ActorMaterializer
 import org.enso.gateway.JsonRpcController
 
 import scala.io.StdIn
@@ -97,7 +96,7 @@ object Main {
     *
     * @param path root path of the newly created project
     */
-  private def createNew(path: String) {
+  private def createNew(path: String): Unit = {
     Package.getOrCreate(new File(path))
     exitSuccess()
   }
@@ -145,12 +144,12 @@ object Main {
   ): Unit = {
     val topScope   = context.getTopScope
     val mainModule = topScope.getModule(mainModuleName)
-    runMain(mainModule)
+    runMain(mainModule): Unit
   }
 
   private def runSingleFile(context: ExecutionContext, file: File): Unit = {
     val mainModule = context.evalModule(file)
-    runMain(mainModule)
+    runMain(mainModule): Unit
   }
 
   private def runMain(mainModule: Module): Value = {
@@ -185,8 +184,6 @@ object Main {
     )
 
     implicit val system: ActorSystem = ActorSystem()
-    implicit val materializer: ActorMaterializer =
-      ActorMaterializer.create(system)
     import system.dispatcher
 
     val languageServerActorName = "languageServer"

engine/runner/src/main/scala/org/enso/runner/Repl.scala

@@ -7,7 +7,7 @@ import org.enso.interpreter.instrument.ReplDebuggerInstrument
 import org.jline.reader.{LineReader, LineReaderBuilder}
 import org.jline.terminal.{Terminal, TerminalBuilder}
 
-import collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 import scala.util.Try
 
 /**

engine/runtime/src/bench/scala/org/enso/interpreter/bench/RegressionTest.scala

@@ -1,15 +1,17 @@
 package org.enso.interpreter.bench
 
-import org.scalatest.{FlatSpec, Matchers}
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 
-import scala.collection.JavaConverters._
+import scala.jdk.CollectionConverters._
+import scala.math.Ordering.Double.IeeeOrdering
 
-class RegressionTest extends FlatSpec with Matchers {
+class RegressionTest extends AnyFlatSpec with Matchers {
   // This tolerance may be adjusted depending on the stability of CI
   final val TOLERANCE = 0.2
 
   val runner     = new BenchmarksRunner
-  val benchmarks = List(runner.getAvailable.asScala: _*)
+  val benchmarks = runner.getAvailable.asScala
 
   benchmarks.foreach { benchmark =>
     benchmark should "not be slower than before" in {

engine/runtime/src/bench/scala/org/enso/interpreter/bench/fixtures/semantic/AtomFixtures.scala

@@ -1,12 +1,8 @@
 package org.enso.interpreter.bench.fixtures.semantic
 
-import org.enso.interpreter.Constants
 import org.enso.interpreter.runtime.Builtins
-import org.enso.interpreter.runtime.scope.TopLevelScope
+import org.enso.interpreter.test.InterpreterRunner
-import org.enso.interpreter.test.{InterpreterException, InterpreterRunner}
+import org.graalvm.polyglot.Value
-import org.graalvm.polyglot.{PolyglotException, Value}
-
-import scala.util.Try
 
 class AtomFixtures extends InterpreterRunner {
   val million: Long = 1000000

engine/runtime/src/main/java/org/enso/interpreter/util/ScalaConversions.java

@@ -1,7 +1,9 @@
 package org.enso.interpreter.util;
 
 import scala.Option;
-import scala.collection.JavaConverters;
+import scala.jdk.javaapi.CollectionConverters;
+import scala.jdk.javaapi.OptionConverters;
+
 import scala.collection.Seq;
 
 import java.util.List;
@@ -16,7 +18,7 @@ public class ScalaConversions {
    * @return the corresponding java optional
    */
   public static <T> Optional<T> asJava(Option<T> option) {
-    return Optional.ofNullable(option.getOrElse(() -> null));
+    return OptionConverters.toJava(option);
   }
 
   /**
@@ -26,6 +28,6 @@ public class ScalaConversions {
    * @return the corresponding java list
    */
   public static <T> List<T> asJava(Seq<T> list) {
-    return JavaConverters.seqAsJavaList(list);
+    return CollectionConverters.asJava(list);
   }
 }

engine/runtime/src/main/scala/org/enso/compiler/Compiler.scala

@@ -1,7 +1,6 @@
 package org.enso.compiler
 
 import java.io.StringReader
-import java.util.Optional
 
 import com.oracle.truffle.api.TruffleFile
 import com.oracle.truffle.api.source.Source
@@ -10,17 +9,13 @@ import org.enso.compiler.generate.AstToAstExpression
 import org.enso.flexer.Reader
 import org.enso.interpreter.builder.{ExpressionFactory, ModuleScopeExpressionFactory}
 import org.enso.interpreter.node.ExpressionNode
-import org.enso.interpreter.runtime.callable.function.Function
 import org.enso.interpreter.runtime.error.ModuleDoesNotExistException
 import org.enso.interpreter.runtime.scope.{LocalScope, ModuleScope, TopLevelScope}
-import org.enso.interpreter.runtime.{Context, Module}
+import org.enso.interpreter.runtime.Context
-import org.enso.interpreter.{Constants, Language}
+import org.enso.interpreter.Language
 import org.enso.polyglot.LanguageInfo
 import org.enso.syntax.text.{AST, Parser}
 
-import scala.collection.JavaConverters._
-import scala.collection.mutable
-
 /**
   * This class encapsulates the static transformation processes that take place
   * on source code, including parsing, desugaring, type-checking, static

engine/runtime/src/main/scala/org/enso/compiler/core/OldAST.scala

@@ -4,8 +4,7 @@ import java.util.Optional
 
 import org.enso.syntax.text.Location
 
-import scala.collection.JavaConverters._
+import scala.jdk.CollectionConverters._
-import scala.language.postfixOps
 
 trait AstExpressionVisitor[+T] {
   def visitLong(l: AstLong): T

engine/runtime/src/main/scala/org/enso/compiler/generate/AstToAstExpression.scala

@@ -6,7 +6,6 @@ import org.enso.compiler.core
 import org.enso.compiler.core._
 import org.enso.compiler.exception.UnhandledEntity
 import org.enso.interpreter.Constants
-import org.enso.interpreter.Constants.Names
 import org.enso.syntax.text.{AST, Location}
 
 // FIXME [AA] All places where we currently throw a `RuntimeException` should
@@ -307,7 +306,7 @@ object AstToAstExpression {
           case _                                  => true
         }
 
-        val suspendPositions = args.view.zipWithIndex.collect {
+        val suspendPositions = args.zipWithIndex.collect {
           case (AstView.SuspendDefaultsOperator(_), ix) => ix
         }
 

engine/runtime/src/test/scala/org/enso/compiler/test/CompilerTest.scala

@@ -1,7 +1,8 @@
 package org.enso.compiler.test
 
-import org.scalatest.{FlatSpec, Matchers}
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 
 trait CompilerRunner {}
 
-trait CompilerTest extends FlatSpec with Matchers with CompilerRunner
+trait CompilerTest extends AnyFlatSpec with Matchers with CompilerRunner

engine/runtime/src/test/scala/org/enso/compiler/test/core/SmartConstructorsTest.scala

@@ -7,10 +7,12 @@ import org.enso.core.CoreGraph.DefinitionGen.Node.{Shape => NodeShape}
 import org.enso.core.CoreGraph.{DefinitionGen => CoreDef}
 import org.enso.graph.{Graph => PrimGraph}
 import org.enso.syntax.text.{AST, Location => AstLocation}
-import org.scalatest.{Assertion, BeforeAndAfterEach, Matchers, WordSpec}
+import org.scalatest.{Assertion, BeforeAndAfterEach}
+import org.scalatest.matchers.should.Matchers
+import org.scalatest.wordspec.AnyWordSpecLike
 
 class SmartConstructorsTest
-    extends WordSpec
+    extends AnyWordSpecLike
     with Matchers
     with BeforeAndAfterEach {
 

engine/runtime/src/test/scala/org/enso/interpreter/test/InterpreterTest.scala

@@ -12,7 +12,9 @@ import org.enso.interpreter.instrument.{
 import org.enso.interpreter.test.CodeLocationsTestInstrument.LocationsEventListener
 import org.enso.polyglot.{ExecutionContext, Function, LanguageInfo}
 import org.graalvm.polyglot.{Context, Value}
-import org.scalatest.{Assertions, FlatSpec, Matchers}
+import org.scalatest.Assertions
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 
 case class LocationsInstrumenter(instrument: CodeLocationsTestInstrument) {
   var bindings: List[EventBinding[LocationsEventListener]] = List()
@@ -87,7 +89,7 @@ trait InterpreterRunner {
   def consumeOut: List[String] = {
     val result = output.toString
     output.reset()
-    result.lines.toList
+    result.linesIterator.toList
   }
 
   def getReplInstrument: ReplDebuggerInstrument = {
@@ -119,7 +121,7 @@ trait InterpreterRunner {
 }
 
 trait InterpreterTest
-    extends FlatSpec
+    extends AnyFlatSpec
     with Matchers
     with InterpreterRunner
     with ValueEquality

engine/runtime/src/test/scala/org/enso/interpreter/test/PackageTest.scala

@@ -5,9 +5,10 @@ import java.io.File
 import org.enso.pkg.Package
 import org.enso.polyglot.{ExecutionContext, LanguageInfo, RuntimeOptions}
 import org.graalvm.polyglot.{Context, Value}
-import org.scalatest.{FlatSpec, Matchers}
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 
-trait PackageTest extends FlatSpec with Matchers with ValueEquality {
+trait PackageTest extends AnyFlatSpec with Matchers with ValueEquality {
 
   def evalTestProject(name: String): Value = {
     val pkgPath =

engine/runtime/src/test/scala/org/enso/interpreter/test/instrument/ReplTest.scala

@@ -1,7 +1,7 @@
 package org.enso.interpreter.test.instrument
 
 import org.enso.interpreter.test.InterpreterTest
-import collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 
 class ReplTest extends InterpreterTest {
   "Repl" should "be able to list local variables in its scope" in {
@@ -20,7 +20,7 @@ class ReplTest extends InterpreterTest {
       executor.exit()
     }
     eval(code)
-    scopeResult.mapValues(_.toString) shouldEqual Map(
+    scopeResult.view.mapValues(_.toString).toMap shouldEqual Map(
       "this" -> "Test",
       "x"    -> "10",
       "y"    -> "20",

engine/runtime/src/test/scala/org/enso/interpreter/test/instrument/ValueExtractorTest.scala

@@ -131,9 +131,9 @@ class ValueExtractorTest extends InterpreterTest {
     val visualizationExpr = "val -> here.foo val * 3"
     val visualization     = module.evalExpression(visualizationExpr)
     val results =
-      values.mapValues(
+      values.view.mapValues(
         v => visualization.execute(v.asInstanceOf[AnyRef]).asLong
-      )
+      ).toMap
     results shouldEqual Map("x" -> 33L, "y" -> 153L)
   }
 

engine/runtime/src/test/scala/org/enso/interpreter/test/semantic/CodeLocationsTest.scala

@@ -11,7 +11,7 @@ import org.enso.interpreter.test.InterpreterTest
 class CodeLocationsTest extends InterpreterTest {
   def debugPrintCodeLocations(code: String): Unit = {
     var off = 0
-    code.lines.toList.foreach { line =>
+    code.linesIterator.toList.foreach { line =>
       val chars: List[Any] = line.toList.map { c =>
           s" ${if (c == ' ') '_' else c} "
         } :+ '↵'