Fix scala-js#115: Add ESModule support

build.sbt

@@ -79,6 +79,7 @@ lazy val seleniumJSEnv: Project = project.
          */
         "org.seleniumhq.selenium" % "selenium-server" % "3.141.59",
         "org.scala-js" %% "scalajs-js-envs" % "1.1.1",
+        "com.google.jimfs" % "jimfs" % "1.1",
         "org.scala-js" %% "scalajs-js-envs-test-kit" % "1.1.1" % "test",
         "com.novocode" % "junit-interface" % "0.11" % "test"
     ),
@@ -135,5 +136,6 @@ lazy val seleniumJSHttpEnvTest: Project = project.
           SeleniumJSEnv.Config()
             .withMaterializeInServer("tmp", "http://localhost:8080/tmp/")
       )
-    }
+    },
+    scalaJSLinkerConfig ~= { _.withModuleKind(ModuleKind.ESModule) }
   )

seleniumJSEnv/src/main/scala/org/scalajs/jsenv/selenium/JSSetup.scala

@@ -1,80 +1,88 @@
 package org.scalajs.jsenv.selenium
 
+import java.nio.charset.StandardCharsets
+import java.nio.file.{Files, Path}
+
+import com.google.common.jimfs.Jimfs
+
 private[selenium] object JSSetup {
-  def setupCode(enableCom: Boolean): String = {
-    s"""
-     |(function() {
-     |  // Buffers for console.log / console.error
-     |  var consoleLog = [];
-     |  var consoleError = [];
-     |
-     |  // Buffer for errors.
-     |  var errors = [];
-     |
-     |  // Buffer for outgoing messages.
-     |  var outMessages = [];
-     |
-     |  // Buffer for incoming messages (used if onMessage not initalized).
-     |  var inMessages = [];
-     |
-     |  // Callback for incoming messages.
-     |  var onMessage = null;
-     |
-     |  function captureConsole(fun, buf) {
-     |    if (!fun) return fun;
-     |    return function() {
-     |      var strs = []
-     |      for (var i = 0; i < arguments.length; ++i)
-     |        strs.push(String(arguments[i]));
-     |
-     |      buf.push(strs.join(" "));
-     |      return fun.apply(this, arguments);
-     |    }
-     |  }
-     |
-     |  console.log = captureConsole(console.log, consoleLog);
-     |  console.error = captureConsole(console.error, consoleError);
-     |
-     |  window.addEventListener('error', function(e) {
-     |    errors.push(e.message)
-     |  });
-     |
-     |  if ($enableCom) {
-     |    this.scalajsCom = {
-     |      init: function(onMsg) {
-     |        onMessage = onMsg;
-     |        window.setTimeout(function() {
-     |          for (var m in inMessages)
-     |            onMessage(inMessages[m]);
-     |          inMessages = null;
-     |        });
-     |      },
-     |      send: function(msg) { outMessages.push(msg); }
-     |    }
-     |  }
-     |
-     |  this.scalajsSeleniumInternalInterface = {
-     |    fetch: function() {
-     |      var res = {
-     |        consoleLog: consoleLog.slice(),
-     |        consoleError: consoleError.slice(),
-     |        errors: errors.slice(),
-     |        msgs: outMessages.slice()
-     |      }
-     |
-     |      consoleLog.length = 0;
-     |      consoleError.length = 0;
-     |      errors.length = 0;
-     |      outMessages.length = 0;
-     |
-     |      return res;
-     |    },
-     |    send: function(msg) {
-     |      if (inMessages !== null) inMessages.push(msg);
-     |      else onMessage(msg);
-     |    }
-     |  };
-     |}).call(this)
-    """.stripMargin
+  def setupFile(enableCom: Boolean): Path = {
+    Files.write(
+      Jimfs.newFileSystem().getPath("setup.js"),
+      s"""
+         |(function() {
+         |  // Buffers for console.log / console.error
+         |  var consoleLog = [];
+         |  var consoleError = [];
+         |
+         |  // Buffer for errors.
+         |  var errors = [];
+         |
+         |  // Buffer for outgoing messages.
+         |  var outMessages = [];
+         |
+         |  // Buffer for incoming messages (used if onMessage not initalized).
+         |  var inMessages = [];
+         |
+         |  // Callback for incoming messages.
+         |  var onMessage = null;
+         |
+         |  function captureConsole(fun, buf) {
+         |    if (!fun) return fun;
+         |    return function() {
+         |      var strs = []
+         |      for (var i = 0; i < arguments.length; ++i)
+         |        strs.push(String(arguments[i]));
+         |
+         |      buf.push(strs.join(" "));
+         |      return fun.apply(this, arguments);
+         |    }
+         |  }
+         |
+         |  console.log = captureConsole(console.log, consoleLog);
+         |  console.error = captureConsole(console.error, consoleError);
+         |
+         |  window.addEventListener('error', function(e) {
+         |    errors.push(e.message)
+         |  });
+         |
+         |  if ($enableCom) {
+         |    this.scalajsCom = {
+         |      init: function(onMsg) {
+         |        onMessage = onMsg;
+         |        window.setTimeout(function() {
+         |          for (var m in inMessages)
+         |            onMessage(inMessages[m]);
+         |          inMessages = null;
+         |        });
+         |      },
+         |      send: function(msg) { outMessages.push(msg); }
+         |    }
+         |  }
+         |
+         |  this.scalajsSeleniumInternalInterface = {
+         |    fetch: function() {
+         |      var res = {
+         |        consoleLog: consoleLog.slice(),
+         |        consoleError: consoleError.slice(),
+         |        errors: errors.slice(),
+         |        msgs: outMessages.slice()
+         |      }
+         |
+         |      consoleLog.length = 0;
+         |      consoleError.length = 0;
+         |      errors.length = 0;
+         |      outMessages.length = 0;
+         |
+         |      return res;
+         |    },
+         |    send: function(msg) {
+         |      if (inMessages !== null) inMessages.push(msg);
+         |      else onMessage(msg);
+         |    }
+         |  };
+         |}).call(this)
+    """.stripMargin.getBytes(StandardCharsets.UTF_8)
+    )
   }
 }

seleniumJSEnv/src/main/scala/org/scalajs/jsenv/selenium/SeleniumRun.scala

@@ -10,6 +10,8 @@ import scala.util.control.NonFatal
 
 import java.util.concurrent.{ConcurrentLinkedQueue, Executors}
 import java.util.function.Consumer
+import java.nio.file.Path
+import java.net.URL
 
 private sealed class SeleniumRun(
     driver: WebDriver with JavascriptExecutor,
@@ -129,20 +131,10 @@ private[selenium] object SeleniumRun {
       newRun: Ctor[T], failed: Throwable => T): T = {
     validator.validate(runConfig)
 
-    val scripts = input.map {
-      case Input.Script(s) => s
-      case _               => throw new UnsupportedInputException(input)
-    }
-
     try {
       withCleanup(FileMaterializer(config.materialization))(_.close()) { m =>
-        val allScriptURLs = (
-            m.materialize("setup.js", JSSetup.setupCode(enableCom)) +:
-            scripts.map(m.materialize)
-        )
-
-        val page = m.materialize("scalajsRun.html", htmlPage(allScriptURLs))
-
+        val setupJsPath = JSSetup.setupFile(enableCom)
+        val page = m.materialize("scalajsRun.html", htmlPage(setupJsPath, input, m))
         withCleanup(newDriver())(maybeCleanupDriver(_, config)) { driver =>
           driver.navigate().to(page)
 
@@ -171,18 +163,31 @@ private[selenium] object SeleniumRun {
   private def maybeCleanupDriver(d: WebDriver, config: SeleniumJSEnv.Config) =
     if (!config.keepAlive) d.close()
 
-  private def htmlPage(scripts: Seq[java.net.URL]): String = {
-    val scriptTags =
-      scripts.map(path => s"<script src='${path.toString}'></script>")
+  private def htmlPage(setupJsPath: Path, input: Seq[Input], materializer: FileMaterializer): String = {
+    val setupJs = makeTag(setupJsPath, "text/javascript", materializer)
+
+    val tags = input.map {
+      case Input.Script(path)   => makeTag(path, "text/javascript", materializer)
+      case Input.ESModule(path) => makeTag(path, "module", materializer)
+      case _                    => throw new UnsupportedInputException(input)
+    }
+
+    val allTags = setupJs +: tags
+
     s"""<html>
        |  <meta charset="UTF-8">
        |  <body>
-       |    ${scriptTags.mkString("\n    ")}
+       |    ${allTags.mkString("\n    ")}
        |  </body>
        |</html>
     """.stripMargin
   }
 
+  private def makeTag(path: Path, tpe: String, materializer: FileMaterializer): String = {
+    val url = materializer.materialize(path)
+    s"<script defer type='$tpe' src='${url.toString}'></script>"
+  }
+
   private class WindowOnErrorException(errs: List[String]) extends Exception(s"JS error: $errs")
 
   private def consumer[A](f: A => Unit): Consumer[A] = new Consumer[A] {

seleniumJSHttpEnvTest/src/main/scala/org/scalajs/jsenv/selenium/CamelCase.scala

@@ -0,0 +1,12 @@
+package org.scalajs.jsenv.selenium
+
+import scala.scalajs.js
+import scala.scalajs.js.annotation.JSImport
+
+object CamelCase {
+  def hello(input: String): String = s"Hello ${camelCase(input)}!"
+
+  @JSImport("https://cdn.skypack.dev/camelcase@^6.0.0", JSImport.Default)
+  @js.native
+  def camelCase(input: String): String = js.native
+}

seleniumJSHttpEnvTest/src/test/scala/org/scalajs/jsenv/selenium/ModuleSupportTest.scala

@@ -0,0 +1,10 @@
+package org.scalajs.jsenv.selenium
+
+import org.junit.Assert._
+import org.junit.Test
+
+class ModuleSupportTest {
+  @Test def testBasicImport(): Unit = {
+    assertEquals("Hello scalaJsSelenium!", CamelCase.hello("scala js selenium"))
+  }
+}