README

$ git clone this gist

bazel build ...

node bazel-genfiles/index.js

bazel version

Build label: 0.5.3-homebrew
Build target: bazel-out/darwin_x86_64-opt/bin/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar
Build time: Sun Aug 6 12:54:10 2017 (1502024050)
Build timestamp: 1502024050
Build timestamp as int: 1502024050

BUILD

load("@io_bazel_rules_scala//scala:scala.bzl", "scala_library", "scala_binary")

scala_library(
    name = "sjsir",
    srcs = ["Test.scala"],
    deps = ["@scalajs//:library"],
    data = ["@scalajs//:compiler"],
    scalacopts = ["-Xplugin:external/scalajs/lib/scalajs-compiler_2.11.11-0.6.19.jar"],
    #scalacopts = ["-Xplugin:$(location @scalajs//:compiler)"], ??? location doesn't seems to be working 
)

scala_binary(
    name = "linker",
    srcs = ["ScalaJsLinker.scala"],
    deps = [
        "@scalajs_ir//jar",
        "@scalajs_tools//jar",
    ],
    main_class = "webapp.ScalaJsLinker",
)

genrule(
    name = "index",
    tools = [":linker"],
    srcs = [":sjsir", "@scalajs//:library"],
    cmd = "./$(location :linker) $(location :sjsir) $(location @scalajs//:library) webapp.Test init $@",
    outs = ["index.js"],
)

scalajs.BUILD

filegroup(
    name = "compiler",
    srcs = glob(["lib/scalajs-compiler_2.11.11-0.6.19.jar"]),
    visibility = ["//visibility:public"],
)

filegroup(
    name = "library",
    srcs = glob(["lib/scalajs-library_2.11-0.6.19.jar"]),
    visibility = ["//visibility:public"],
)

ScalaJsLinker.scala

package webapp

import java.io.File

import org.scalajs.core.tools.io._
import org.scalajs.core.tools.linker.{ModuleInitializer, StandardLinker}
import org.scalajs.core.tools.logging.ScalaConsoleLogger

object ScalaJsLinker extends App {

  val in = IRFileCache.IRContainer.fromJar(new File(args(0)))
  val lib = IRFileCache.IRContainer.fromJar(new File(args(1)))
  val sjsirFiles = new IRFileCache().newCache.cached(Seq(in, lib))

  StandardLinker(StandardLinker.Config())
    .link(sjsirFiles, Seq(ModuleInitializer.mainMethod(args(2), args(3))), WritableFileVirtualJSFile(new File(args(4))), new ScalaConsoleLogger)
}

Test.scala

package webapp

object Test {
	def init(): Unit = {
		println("Oi!")
	}
}

WORKSPACE

git_repository(
    name = "io_bazel_rules_scala",
    remote = "https://github.com/bazelbuild/rules_scala.git",
    commit = "1947a197f849738d926e609584cfda4ecf669bd9",
)

load("@io_bazel_rules_scala//scala:scala.bzl", "scala_repositories")

scala_repositories()

new_http_archive(
    name = "scalajs",
    url = "https://www.scala-js.org/files/scalajs_2.11-0.6.19.tgz",
    build_file = "scalajs.BUILD",
    strip_prefix = "scalajs_2.11-0.6.19",
)

maven_jar(name = "scalajs_ir", artifact = "org.scala-js:scalajs-ir_2.11:0.6.19")
maven_jar(name = "scalajs_tools", artifact = "org.scala-js:scalajs-tools_2.11:0.6.19")