Cross-build for Scala 2.11

Author: armanbilge

.github/workflows/ci.yml

@@ -26,7 +26,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        scala: [2.12.14, 2.13.6, 3.0.2]
+        scala: [2.11.12, 2.12.14, 2.13.6, 3.0.2]
         java: [adopt@1.8]
         ci: [ciNode, ciFirefox, ciChrome, ciJSDOMNodeJS]
     runs-on: ${{ matrix.os }}

build.sbt

@@ -45,7 +45,7 @@ ThisBuild / scmInfo := Some(
 
 // build and matrix configuration
 
-ThisBuild / crossScalaVersions := Seq("2.12.14", "2.13.6", "3.0.2")
+ThisBuild / crossScalaVersions := Seq("2.11.12", "2.12.14", "2.13.6", "3.0.2")
 
 ThisBuild / githubWorkflowBuildPreamble ++= Seq(
   WorkflowStep.Use(

core/src/test/scala/org/scalajs/macrotaskexecutor/MacrotaskExecutorSuite.scala

@@ -30,7 +30,7 @@ class MacrotaskExecutorSuite extends FunSuite {
       if (n <= 0)
         Future(0)
       else
-        Future.unit.flatMap(_ => loop(n - 1)).map(_ + 1)
+        Future.successful(()).flatMap(_ => loop(n - 1)).map(_ + 1)
 
     val start = System.currentTimeMillis()
     val MinimumClamp = 10000 * 2 * 4    // HTML5 specifies a 4ms clamp (https://developer.mozilla.org/en-US/docs/Web/API/WindowTimers.setTimeout#Minimum.2F_maximum_delay_and_timeout_nesting)
@@ -52,7 +52,7 @@ class MacrotaskExecutorSuite extends FunSuite {
     def loop(): Future[Unit] =
       Future(cancel) flatMap { canceled =>
         if (canceled)
-          Future.unit
+          Future.successful(())
         else
           loop()
       }

webworker/src/test/scala/org/scalajs/macrotaskexecutor/WebWorkerMacrotaskSuite.scala

@@ -17,6 +17,7 @@
 package org.scalajs.macrotaskexecutor
 
 import munit.FunSuite
+import org.scalajs.dom.MessageEvent
 import org.scalajs.dom.webworkers.Worker
 
 import scala.concurrent.Promise
@@ -41,7 +42,7 @@ class WebWorkerMacrotaskSuite extends FunSuite {
       s"file://${targetDir}/scala-js-macrotask-executor-webworker-fastopt/main.js"
     )
 
-    worker.onmessage = { event =>
+    worker.onmessage = { (event: MessageEvent) =>
       event.data match {
         case log: String      => println(log)
         case success: Boolean => p.success(success)