Merge pull request #7439 from Lacaranian/add-readers-test

Partial fix for lampepfl#7113: Fix Scala.js codegen for Explicit Returns

Author: sjrd

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

@@ -723,9 +723,10 @@ class JSCodeGen()(implicit ctx: Context) {
           mutable = false, rest = false)
     }
 
-    def genBody() =
+    def genBody() = localNames.makeLabeledIfRequiresEnclosingReturn(resultIRType) {
       if (resultIRType == jstpe.NoType) genStat(tree)
       else genExpr(tree)
+    }
 
     //if (!isScalaJSDefinedJSClass(currentClassSym)) {
     val flags = js.MemberFlags.empty.withNamespace(namespace)

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

@@ -92,6 +92,18 @@ object JSEncoding {
         returnLabelName = Some(freshName("_return"))
       js.Ident(returnLabelName.get)
     }
+
+    /* If this `LocalNameGenerator` has a `returnLabelName` (often added in the
+     * construction of the `body` argument), wrap the resulting js.Tree to use that label.
+     */
+    def makeLabeledIfRequiresEnclosingReturn(tpe: jstpe.Type)(body: js.Tree)(implicit pos: ir.Position): js.Tree = {
+      returnLabelName match {
+        case None =>
+          body
+        case Some(labelName) =>
+          js.Labeled(js.Ident(labelName), tpe, body)
+      }
+    }
   }
 
   private object LocalNameGenerator {

project/Build.scala

@@ -979,7 +979,7 @@ object Build {
         (
           (dir / "shared/src/test/scala/org/scalajs/testsuite/compiler" ** (("*.scala":FileFilter) -- "RegressionTest.scala" -- "ReflectiveCallTest.scala")).get
           ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/javalib/lang" ** (("*.scala": FileFilter) -- "ClassTest.scala" -- "StringTest.scala")).get
-          ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/javalib/io" ** (("*.scala": FileFilter) -- "ByteArrayInputStreamTest.scala" -- "ByteArrayOutputStreamTest.scala" -- "DataInputStreamTest.scala" -- "DataOutputStreamTest.scala" -- "InputStreamTest.scala" -- "OutputStreamWriterTest.scala" -- "PrintStreamTest.scala" -- "ReadersTest.scala" -- "CommonStreamsTests.scala")).get
+          ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/javalib/io" ** (("*.scala": FileFilter) -- "ByteArrayInputStreamTest.scala" -- "ByteArrayOutputStreamTest.scala" -- "DataInputStreamTest.scala" -- "DataOutputStreamTest.scala" -- "InputStreamTest.scala" -- "OutputStreamWriterTest.scala" -- "PrintStreamTest.scala" -- "CommonStreamsTests.scala")).get
           ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/javalib/math" ** "*.scala").get
           ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/javalib/net" ** (("*.scala": FileFilter) -- "URITest.scala")).get
           ++ (dir / "shared/src/test/scala/org/scalajs/testsuite/javalib/security" ** "*.scala").get