Revive the Scala.js backend.

.drone.yml

@@ -34,7 +34,7 @@ pipeline:
     image: lampepfl/dotty:2018-10-01
     commands:
       - cp -R . /tmp/2/ && cd /tmp/2/
-      - ./project/scripts/sbt ";dotty-bootstrapped/compile ;dotty-bootstrapped/test"
+      - ./project/scripts/sbt ";dotty-bootstrapped/compile ;dotty-bootstrapped/test ;sjsSandbox/run"
       - ./project/scripts/bootstrapCmdTests
 
   test_sbt:

build.sbt

@@ -20,6 +20,8 @@ val scalap = Build.scalap
 val dist = Build.dist
 val `dist-bootstrapped` = Build.`dist-bootstrapped`
 
+val sjsSandbox = Build.sjsSandbox
+
 val `sbt-dotty` = Build.`sbt-dotty`
 val `vscode-dotty` = Build.`vscode-dotty`
 

compiler/sjs/backend/sjs/GenSJSIR.scala → compiler/src/dotty/tools/backend/sjs/GenSJSIR.scala

@@ -9,6 +9,7 @@ class GenSJSIR extends Phase {
   def phaseName: String = "genSJSIR"
 
   def run(implicit ctx: Context): Unit = {
-    new JSCodeGen().run()
+    if (ctx.settings.scalajs.value)
+      new JSCodeGen().run()
   }
 }