SI-7696 --show-log on bad failure

On non-zero exit, no transcript is recorded.
Show log in that important use case.

TestInfo encapsulates a bit of useful interface.

Author: som-snytt

src/main/scala/scala/tools/partest/nest/NestUI.scala

@@ -73,35 +73,28 @@ object NestUI {
     f"$word $testNumber - $testIdent%-40s$reasonString"
   }
 
-  def reportTest(state: TestState) = {
+  def reportTest(state: TestState, info: TestInfo) = {
     if (isTerse && state.isOk) {
       if (dotCount >= DotWidth) {
         outline("\n.")
         dotCount = 1
-      }
-      else {
+      } else {
         outline(".")
         dotCount += 1
       }
-    }
-    else {
+    } else {
       echo(statusLine(state))
       if (!state.isOk) {
         if (isDiffy) {
           val differ = bold(red("% ")) + "diff "
           state.transcript find (_ startsWith differ) foreach (echo(_))
         }
         if (isLogging) {
-          import scala.util.matching.Regex
           def log(f: File) = {
             echo(bold(cyan(s"##### Log file '$f' from failed test #####\n")))
             echo(f.fileContents)
           }
-          val prompt = bold(red("% "))
-          val differ = raw"(?s)${Regex.quote(prompt)}diff (\S*).*".r
-          state.transcript.collect {
-            case differ(f) => f
-          } foreach (log(_))
+          if (info.logFile.canRead) log(info.logFile)
         }
       }
     }

src/main/scala/scala/tools/partest/nest/Runner.scala

@@ -42,8 +42,35 @@ class TestTranscript {
   }
 }
 
+trait TestInfo {
+  /** pos/t1234 */
+  def testIdent: String
+
+  /** pos */
+  def kind: String
+
+  // inputs
+
+  /** pos/t1234.scala or pos/t1234 if dir */
+  def testFile: File
+
+  /** pos/t1234.check */
+  def checkFile: File
+
+  /** pos/t1234.flags */
+  def flagsFile: File
+
+  // outputs
+
+  /** pos/t1234-pos.obj */
+  def outFile: File
+
+  /** pos/t1234-pos.log */
+  def logFile: File
+}
+
 /** Run a single test. Rubber meets road. */
-class Runner(val testFile: File, val suiteRunner: SuiteRunner) {
+class Runner(val testFile: File, val suiteRunner: SuiteRunner) extends TestInfo {
 
   import suiteRunner.{fileManager => fm, _}
   val fileManager = fm
@@ -802,7 +829,7 @@ class SuiteRunner(
           catch {
             case t: Throwable => throw new RuntimeException(s"Error running $testFile", t)
           }
-        NestUI.reportTest(state)
+        NestUI.reportTest(state, runner)
         runner.cleanup()
         state
       }