Fix scala#9785: Scala.js: Handle the typeof JSGlobalRef(_) corner case.

This requires two things:

- make sure that `SelectStatic` does not expand references to
  global scopes, and
- when compiling `js.typeOf(globalRef)`, emit a
  `JSTypeOfGlobalRef(_)` instead of a
  `JSUnaryOp(typeof, JSGlobalRef(_))`.

Author: sjrd

compiler/src/dotty/tools/backend/sjs/JSCodeGen.scala

@@ -2932,7 +2932,11 @@ class JSCodeGen()(using genCtx: Context) {
       case TYPEOF =>
         // js.typeOf(arg)
         val arg = genArgs1
-        genAsInstanceOf(js.JSUnaryOp(js.JSUnaryOp.typeof, arg), defn.StringType)
+        val typeofExpr = arg match {
+          case arg: js.JSGlobalRef => js.JSTypeOfGlobalRef(arg)
+          case _                   => js.JSUnaryOp(js.JSUnaryOp.typeof, arg)
+        }
+        js.AsInstanceOf(typeofExpr, jstpe.ClassType(jsNames.BoxedStringClass))
 
       case STRICT_EQ =>
         // js.special.strictEquals(arg1, arg2)

compiler/src/dotty/tools/dotc/transform/SelectStatic.scala

@@ -11,6 +11,8 @@ import dotty.tools.dotc.core._
 import dotty.tools.dotc.transform.MegaPhase._
 import dotty.tools.dotc.transform.SymUtils._
 
+import dotty.tools.backend.sjs.JSDefinitions.jsdefn
+
 /** Removes selects that would be compiled into GetStatic
  * otherwise backend needs to be aware that some qualifiers need to be dropped.
  * Similar transformation seems to be performed by flatten in nsc
@@ -31,6 +33,7 @@ class SelectStatic extends MiniPhase with IdentityDenotTransformer {
     val tree1 =
       if isStaticRef && !tree.qualifier.symbol.isAllOf(JavaModule) && !tree.qualifier.isType then
         if isPureExpr(tree.qualifier) then ref(sym)
+        else if ctx.settings.scalajs.value && sym.is(Module) && sym.moduleClass.hasAnnotation(jsdefn.JSGlobalScopeAnnot) then ref(sym)
         else Block(List(tree.qualifier), ref(sym))
       else tree
 

project/Build.scala

@@ -1009,6 +1009,12 @@ object Build {
       scalaJSLinkerConfig ~= { _.withSemantics(build.TestSuiteLinkerOptions.semantics _) },
       scalaJSModuleInitializers in Test ++= build.TestSuiteLinkerOptions.moduleInitializers,
 
+      jsEnvInput in Test := {
+        val resourceDir = fetchScalaJSSource.value / "test-suite/js/src/test/resources"
+        val f = (resourceDir / "NonNativeJSTypeTestNatives.js").toPath
+        org.scalajs.jsenv.Input.Script(f) +: (jsEnvInput in Test).value
+      },
+
       managedSources in Compile ++= {
         val dir = fetchScalaJSSource.value / "test-suite/js/src/main/scala"
         val filter = (
@@ -1049,7 +1055,6 @@ object Build {
             -- "ExportsTest.scala" // JS exports
             -- "IterableTest.scala" // non-native JS classes
             -- "JSExportStaticTest.scala" // JS exports
-            -- "JSNativeInPackage.scala" // #9785 tests fail due to js.typeOf(globalVar) being incorrect
             -- "JSOptionalTest.scala" // non-native JS classes
             -- "JSSymbolTest.scala" // non-native JS classes
             -- "MiscInteropTest.scala" // non-native JS classes