Add updateCheckFiles to override tests check files with output

Also updated `testFromTasty` checkfiles using it to remove first comment line
which cannot be tested on Windows adn added missing EOLs.

Author: nicolasstucki

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -303,7 +303,7 @@ class CompilationTests extends ParallelTesting {
 }
 
 object CompilationTests {
-  implicit val summaryReport: SummaryReporting = new SummaryReport
+  implicit val summaryReport: SummaryReporting = new SummaryReport(updateCheckFiles = false)
   @AfterClass def cleanup(): Unit = summaryReport.echoSummary()
 
   def sources(paths: JStream[Path], excludedFiles: List[String] = Nil): List[String] = {

compiler/test/dotty/tools/dotc/FromTastyTests.scala

@@ -51,6 +51,6 @@ class FromTastyTests extends ParallelTesting {
 }
 
 object FromTastyTests {
-  implicit val summaryReport: SummaryReporting = new SummaryReport
+  implicit val summaryReport: SummaryReporting = new SummaryReport(updateCheckFiles = false)
   @AfterClass def cleanup(): Unit = summaryReport.echoSummary()
 }

compiler/test/dotty/tools/dotc/IdempotencyTests.scala

@@ -72,6 +72,6 @@ class IdempotencyTests extends ParallelTesting {
 }
 
 object IdempotencyTests {
-  implicit val summaryReport: SummaryReporting = new SummaryReport
+  implicit val summaryReport: SummaryReporting = new SummaryReport(updateCheckFiles = false)
   @AfterClass def cleanup(): Unit = summaryReport.echoSummary()
 }

compiler/test/dotty/tools/vulpix/ParallelTesting.scala

@@ -505,6 +505,12 @@ trait ParallelTesting extends RunnerOrchestration { self =>
       this
     }
 
+    protected def updateCheckFile(checkFile: JFile, lines: Seq[String]): Unit = {
+      val outFile = dotty.tools.io.File(checkFile.toPath)
+      outFile.writeAll(lines.mkString("", EOL, EOL))
+      echo("Updated checkfile: " + checkFile.getPath)
+    }
+
     /** Returns all files in directory or the file if not a directory */
     private def flattenFiles(f: JFile): Array[JFile] =
       if (f.isDirectory) f.listFiles.flatMap(flattenFiles)
@@ -537,28 +543,32 @@ trait ParallelTesting extends RunnerOrchestration { self =>
                     val output = Source.fromFile(outDir.getParent + "_decompiled" + JFile.separator + outDir.getName
                       + JFile.separator + "decompiled.scala", "UTF-8").getLines().map {line =>
                       stripTrailingWhitespaces.unapplySeq(line).map(_.head).getOrElse(line)
-                    }.toList
+                    }.filter(!_.startsWith(ignoredFilePathLine)).toList
 
-                    val check: String = Source.fromFile(checkFile, "UTF-8").getLines().filter(!_.startsWith(ignoredFilePathLine))
+                    val check: String = Source.fromFile(checkFile, "UTF-8").getLines()
                       .mkString(EOL)
 
-                    if (output.filter(!_.startsWith(ignoredFilePathLine)).mkString(EOL) != check) {
+                    if (output.mkString(EOL) != check) {
                       val outFile = dotty.tools.io.File(checkFile.toPath).addExtension(".out")
-                      outFile.writeAll(output.mkString(EOL))
-                      val msg =
-                        s"""Output differed for test $name, use the following command to see the diff:
-                           |  > diff $checkFile $outFile
+                      if (summaryReport.updateCheckFiles) {
+                        updateCheckFile(checkFile, output)
+                      } else {
+                        outFile.writeAll(output.mkString("", EOL, ""))
+                        val msg =
+                          s"""Output differed for test $name, use the following command to see the diff:
+                             |  > diff $checkFile $outFile
                         """.stripMargin
 
-                      echo(msg)
-                      addFailureInstruction(msg)
+                        echo(msg)
+                        addFailureInstruction(msg)
 
-                      // Print build instructions to file and summary:
-                      val buildInstr = testSource.buildInstructions(0, rep.warningCount)
-                      addFailureInstruction(buildInstr)
+                        // Print build instructions to file and summary:
+                        val buildInstr = testSource.buildInstructions(0, rep.warningCount)
+                        addFailureInstruction(buildInstr)
 
-                      // Fail target:
-                      failTestSource(testSource)
+                        // Fail target:
+                        failTestSource(testSource)
+                      }
                     }
                   case _ =>
                 }
@@ -631,6 +641,9 @@ trait ParallelTesting extends RunnerOrchestration { self =>
 
             // Fail target:
             failTestSource(testSource)
+
+            if (summaryReport.updateCheckFiles)
+              updateCheckFile(checkFile.get, outputLines)
           }
         }
 
@@ -766,7 +779,11 @@ trait ParallelTesting extends RunnerOrchestration { self =>
         }
         def checkFileTest(sourceName: String, checkFile: JFile, actual: List[String]) = {
           val expexted = Source.fromFile(checkFile, "UTF-8").getLines().toList
-          diffMessage(sourceName, actual, expexted).foreach(fail)
+          for (msg <- diffMessage(sourceName, actual, expexted)) {
+            fail(msg)
+            if (summaryReport.updateCheckFiles)
+              updateCheckFile(checkFile, actual)
+          }
         }
 
         val (compilerCrashed, expectedErrors, actualErrors, hasMissingAnnotations, errorMap) = testSource match {

compiler/test/dotty/tools/vulpix/SummaryReport.scala

@@ -40,6 +40,9 @@ trait SummaryReporting {
 
   /** Echoes contents of `it` to file *immediately* then flushes */
   def echoToLog(it: Iterator[String]): Unit
+
+  /** Echoes outputs of the test into the thier checkfiles */
+  def updateCheckFiles: Boolean
 }
 
 /** A summary report that doesn't do anything */
@@ -53,12 +56,13 @@ final class NoSummaryReport extends SummaryReporting {
   def echoSummary(): Unit = ()
   def echoToLog(msg: String): Unit = ()
   def echoToLog(it: Iterator[String]): Unit = ()
+  def updateCheckFiles: Boolean = false
 }
 
 /** A summary report that logs to both stdout and the `TestReporter.logWriter`
  *  which outputs to a log file in `./testlogs/`
  */
-final class SummaryReport extends SummaryReporting {
+final class SummaryReport(val updateCheckFiles: Boolean) extends SummaryReporting {
   import scala.collection.JavaConverters._
 
   private val startingMessages = new java.util.concurrent.ConcurrentLinkedDeque[String]

compiler/test/dotty/tools/vulpix/VulpixMetaTests.scala

@@ -20,7 +20,7 @@ class VulpixMetaTests extends ParallelTesting {
   def isInteractive = false // Don't beautify output for interactive use.
   def testFilter = None // Run all the tests.
 
-  implicit val summaryReport: SummaryReporting = new SummaryReport
+  implicit val summaryReport: SummaryReporting = new SummaryReport(updateCheckFiles = false)
   implicit def testGroup: TestGroup = TestGroup("VulpixMetaTests")
 
   @Test def compilePos: Unit = compileFilesInDir("tests/vulpix-tests/meta/pos", defaultOptions).checkCompile()

tests/pos/classWithCompObj.decompiled

@@ -1,3 +1,2 @@
-/** Decompiled from out/posTestFromTasty/pos/classWithCompObj/Foo.class */
 class Foo()
-object Foo
+object Foo

tests/pos/conforms.decompiled

@@ -1,4 +1,3 @@
-/** Decompiled from out/posTestFromTasty/pos/conforms/Test.class */
 object Test {
   def f[A, B](x: A)(implicit e: scala.Predef.<:<[A, B]): B = e.apply(x)
-}
+}

tests/pos/i0306.decompiled

@@ -1,4 +1,3 @@
-/** Decompiled from out/posTestFromTasty/pos/i0306/bar.class */
 object bar {
   class C[T <: scala.Seq[_ >: scala.Nothing <: scala.Any]]()
   val x: scala.AnyRef = new bar.C[scala.collection.Seq[_ >: scala.Nothing <: scala.Any]]()

tests/pos/i1181.decompiled

@@ -1,4 +1,3 @@
-/** Decompiled from out/posTestFromTasty/pos/i1181/Test.class */
 object Test {
   def foo[M[_$1]](x: M[scala.Int]): M[scala.Int] = x
   type Alias[A] = scala.Tuple2[A, A]