Print colored diff for scripted tests

Author: nicolasstucki

compiler/src/dotty/tools/dotc/util/DiffUtil.scala

@@ -59,6 +59,13 @@ object DiffUtil {
     (fnd, exp, totalChange.toDouble / (expected.length + found.length))
   }
 
+  def mkColoredLinesDiff(expected: Seq[String], actual: Seq[String]): String = {
+    val expectedSize = DiffUtil.EOF.length max expected.map(_.length).max
+    actual.padTo(expected.length, "").zip(expected.padTo(actual.length, "")).map { case (act, exp) =>
+      DiffUtil.mkColoredLineDiff(exp, act, expectedSize)
+    }.mkString("\n")
+  }
+
   def mkColoredLineDiff(expected: String, actual: String, expectedSize: Int): String = {
     lazy val diff = {
       val tokens = splitTokens(expected, Nil).toArray

compiler/test/dotty/tools/repl/ScriptedTests.scala

@@ -1,15 +1,15 @@
 package dotty.tools
 package repl
 
-import java.io.{ File => JFile }
+import java.io.{File => JFile}
 
 import org.junit.Assert._
 import org.junit.Test
 
 import scala.collection.mutable.ArrayBuffer
 import scala.io.Source
-
 import dotc.reporting.MessageRendering
+import dotty.tools.dotc.util.DiffUtil
 
 /** Runs all tests contained in `compiler/test-resources/repl/` */
 class ScriptedTests extends ReplTest with MessageRendering {
@@ -56,11 +56,11 @@ class ScriptedTests extends ReplTest with MessageRendering {
     def filterEmpties(line: String): List[String] =
       line.replaceAll("""(?m)\s+$""", "") match {
         case "" => Nil
-        case nonEmptyLine => nonEmptyLine :: Nil
+        case nonEmptyLine => nonEmptyLine.split("\n").toList
       }
 
     val expectedOutput =
-      Source.fromFile(f).getLines.flatMap(filterEmpties).mkString("\n")
+      Source.fromFile(f).getLines.flatMap(filterEmpties).toList
     val actualOutput = {
       resetToInitial()
       init()
@@ -71,15 +71,11 @@ class ScriptedTests extends ReplTest with MessageRendering {
         buf.append(out)
         nstate
       }
-      buf.flatMap(filterEmpties).mkString("\n")
+      buf.flatMap(filterEmpties).toList
     }
 
     if (expectedOutput != actualOutput) {
-      println("expected =========>")
-      println(expectedOutput)
-      println("actual ===========>")
-      println(actualOutput)
-
+      println(DiffUtil.mkColoredLinesDiff(expectedOutput, actualOutput))
       fail(s"Error in file $f, expected output did not match actual")
     }
   }

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

@@ -535,10 +535,7 @@ trait ParallelTesting extends RunnerOrchestration { self =>
 
           if (outputLines.length != checkLines.length || !linesMatch) {
             // Print diff to files and summary:
-            val expectedSize = DiffUtil.EOF.length max checkLines.map(_.length).max
-            val diff = outputLines.padTo(checkLines.length, "").zip(checkLines.padTo(outputLines.length, "")).map { case (act, exp) =>
-              DiffUtil.mkColoredLineDiff(exp, act, expectedSize)
-            }.mkString("\n")
+            val diff = DiffUtil.mkColoredLinesDiff(checkLines, outputLines)
 
             val msg =
               s"""|Output from '$sourceTitle' did not match check file.