fix resoruce leaks in tests and REPL, fixes #8358

bench-run/src/main/scala/dotty/tools/benchmarks/Main.scala

@@ -8,6 +8,7 @@ import org.openjdk.jmh.runner.options._
 import java.util.concurrent.TimeUnit
 
 import scala.io.Source
+import scala.util.Using
 
 object Bench {
   def main(args: Array[String]): Unit = {
@@ -57,7 +58,7 @@ object Bench {
   }
 
   def paramsFromFile(file: String): Array[(String, Array[String])] = {
-    Source.fromFile(file).getLines.toArray.map { l =>
+    Using(Source.fromFile(file))(_.getLines.toArray).get.map { l =>
       val Array(param, values) = l split ':'
       (param, values split ',')
     }

bench/src/main/scala/Benchmarks.scala

@@ -15,6 +15,7 @@ import java.util.concurrent.TimeUnit
 import java.io.{File, FileOutputStream, BufferedWriter, FileWriter}
 import scala.collection.JavaConverters._
 import scala.io.Source
+import scala.util.Using
 
 object Bench {
   val COMPILE_OPTS_FILE = "compile.txt"
@@ -77,7 +78,7 @@ object Bench {
   }
 
   def readCompileOptions: Seq[String] =
-    Source.fromFile(COMPILE_OPTS_FILE).getLines.toSeq
+    Using(Source.fromFile(COMPILE_OPTS_FILE))(_.getLines.toSeq).get
 }
 
 @State(Scope.Benchmark)

bin/test/TestScripts.scala

@@ -5,6 +5,7 @@ import org.junit.{Before, After, Test}
 
 import scala.io.Source
 import scala.sys.process.{Process, ProcessLogger}
+import scala.util.Using
 import java.io.{File => JFile, FileNotFoundException}
 
 class TestScripts {
@@ -29,7 +30,7 @@ class TestScripts {
 
   private def deletePackages: Unit = {
     try {
-      for (jar <- Source.fromFile("./.packages").getLines())
+      for (jar <- Using(Source.fromFile("./.packages"))(_.getLines().toList).get)
         delete(jar)
 
       delete("./.packages")

compiler/src/dotty/tools/repl/ReplDriver.scala

@@ -25,6 +25,7 @@ import org.jline.reader._
 
 import scala.annotation.tailrec
 import scala.collection.JavaConverters._
+import scala.util.Using
 
 /** The state of the REPL contains necessary bindings instead of having to have
  *  mutation
@@ -351,7 +352,7 @@ class ReplDriver(settings: Array[String],
     case Load(path) =>
       val file = new JFile(path)
       if (file.exists) {
-        val contents = scala.io.Source.fromFile(file, "UTF-8").mkString
+        val contents = Using(scala.io.Source.fromFile(file, "UTF-8"))(_.mkString).get
         run(contents)
       }
       else {

compiler/test/debug/Gen.scala

@@ -1,5 +1,6 @@
 import scala.io.Source
 import scala.collection.mutable.ListBuffer
+import scala.util.Using
 
 /** Automate testing debuggability of generated code using JDB and expect
  *
@@ -64,7 +65,7 @@ object Gen {
   }
 
   def parse(file: String): Program = {
-    val lines = Source.fromFile(file).getLines().toBuffer
+    val lines = Using(Source.fromFile(file))(_.getLines().toBuffer).get
 
     val breaks = new ListBuffer[Break]()
     val cmds = new ListBuffer[Command]()

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

@@ -6,6 +6,7 @@ import vulpix.TestConfiguration
 import java.lang.System.{lineSeparator => EOL}
 import java.io.{ByteArrayOutputStream, File => JFile, PrintStream}
 import scala.io.Source
+import scala.util.Using
 
 import scala.collection.mutable.ArrayBuffer
 
@@ -56,26 +57,8 @@ class ReplTest(withStaging: Boolean = false, out: ByteArrayOutputStream = new By
 
   def testFile(f: JFile): Unit = {
     val prompt = "scala>"
-    val lines = Source.fromFile(f, "UTF-8").getLines().buffered
 
-    assert(lines.head.startsWith(prompt),
-           s"""Each file has to start with the prompt: "$prompt"""")
-
-    def extractInputs(prompt: String): List[String] = {
-      val input = lines.next()
-
-      if (!input.startsWith(prompt)) extractInputs(prompt)
-      else if (lines.hasNext) {
-        // read lines and strip trailing whitespace:
-        while (lines.hasNext && !lines.head.startsWith(prompt))
-          lines.next()
-
-        input :: { if (lines.hasNext) extractInputs(prompt) else Nil }
-      }
-      else Nil
-    }
-
-    def evaluate(state: State, input: String, prompt: String) =
+    def evaluate(state: State, input: String) =
       try {
         val nstate = run(input.drop(prompt.length))(state)
         val out = input + EOL + storedOutput()
@@ -94,13 +77,18 @@ class ReplTest(withStaging: Boolean = false, out: ByteArrayOutputStream = new By
       }
 
     val expectedOutput =
-      Source.fromFile(f, "UTF-8").getLines().flatMap(filterEmpties).mkString(EOL)
+      Using(Source.fromFile(f, "UTF-8"))(_.getLines().flatMap(filterEmpties).mkString(EOL)).get
     val actualOutput = {
       resetToInitial()
-      val inputRes = extractInputs(prompt)
+
+      val lines = Using(Source.fromFile(f, "UTF-8"))(_.getLines.toList).get
+      assert(lines.head.startsWith(prompt),
+        s"""Each file has to start with the prompt: "$prompt"""")
+      val inputRes = lines.filter(_.startsWith(prompt))
+
       val buf = new ArrayBuffer[String]
       inputRes.foldLeft(initialState) { (state, input) =>
-        val (out, nstate) = evaluate(state, input, prompt)
+        val (out, nstate) = evaluate(state, input)
         buf.append(out)
 
         assert(out.endsWith("\n"),

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

@@ -1,6 +1,7 @@
 package dotty.tools.vulpix
 
 import scala.io.Source
+import scala.util.Using
 import java.io.File
 import java.lang.System.{lineSeparator => EOL}
 import java.nio.file.{Files, Paths}
@@ -17,7 +18,7 @@ object FileDiff {
   def check(sourceTitle: String, outputLines: Seq[String], checkFile: String): Option[String] = {
     val checkLines =
       if (!(new File(checkFile)).exists) Nil
-      else Source.fromFile(checkFile, "UTF-8").getLines().toList
+      else Using(Source.fromFile(checkFile, "UTF-8"))(_.getLines().toList).get
 
     def linesMatch =
       outputLines.length == checkLines.length &&

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

@@ -12,7 +12,7 @@ import java.util.concurrent.{TimeUnit, TimeoutException, Executors => JExecutors
 
 import scala.collection.mutable
 import scala.io.Source
-import scala.util.{Random, Try, Failure => TryFailure, Success => TrySuccess}
+import scala.util.{Random, Try, Failure => TryFailure, Success => TrySuccess, Using}
 import scala.util.control.NonFatal
 import scala.util.matching.Regex
 
@@ -654,33 +654,35 @@ trait ParallelTesting extends RunnerOrchestration { self =>
       val errorMap = new HashMap[String, Integer]()
       var expectedErrors = 0
       files.filter(_.getName.endsWith(".scala")).foreach { file =>
-        Source.fromFile(file, "UTF-8").getLines().zipWithIndex.foreach { case (line, lineNbr) =>
-          val errors = line.toSeq.sliding("// error".length).count(_.unwrap == "// error")
-          if (errors > 0)
-            errorMap.put(s"${file.getPath}:$lineNbr", errors)
-
-          val noposErrors = line.toSeq.sliding("// nopos-error".length).count(_.unwrap == "// nopos-error")
-          if (noposErrors > 0) {
-            val nopos = errorMap.get("nopos")
-            val existing: Integer = if (nopos eq null) 0 else nopos
-            errorMap.put("nopos", noposErrors + existing)
-          }
+        Using(Source.fromFile(file, "UTF-8")) { source =>
+          source.getLines.zipWithIndex.foreach { case (line, lineNbr) =>
+            val errors = line.toSeq.sliding("// error".length).count(_.unwrap == "// error")
+            if (errors > 0)
+              errorMap.put(s"${file.getPath}:$lineNbr", errors)
+
+            val noposErrors = line.toSeq.sliding("// nopos-error".length).count(_.unwrap == "// nopos-error")
+            if (noposErrors > 0) {
+              val nopos = errorMap.get("nopos")
+              val existing: Integer = if (nopos eq null) 0 else nopos
+              errorMap.put("nopos", noposErrors + existing)
+            }
 
-          val anyposErrors = line.toSeq.sliding("// anypos-error".length).count(_.unwrap == "// anypos-error")
-          if (anyposErrors > 0) {
-            val anypos = errorMap.get("anypos")
-            val existing: Integer = if (anypos eq null) 0 else anypos
-            errorMap.put("anypos", anyposErrors + existing)
-          }
+            val anyposErrors = line.toSeq.sliding("// anypos-error".length).count(_.unwrap == "// anypos-error")
+            if (anyposErrors > 0) {
+              val anypos = errorMap.get("anypos")
+              val existing: Integer = if (anypos eq null) 0 else anypos
+              errorMap.put("anypos", anyposErrors + existing)
+            }
 
-          val possibleTypos = List("//error" -> "// error", "//nopos-error" -> "// nopos-error", "//anypos-error" -> "// anypos-error")
-          for ((possibleTypo, expected) <- possibleTypos) {
-            if (line.contains(possibleTypo))
-              echo(s"Warning: Possible typo in error tag in file ${file.getCanonicalPath}:$lineNbr: found `$possibleTypo` but expected `$expected`")
-          }
+            val possibleTypos = List("//error" -> "// error", "//nopos-error" -> "// nopos-error", "//anypos-error" -> "// anypos-error")
+            for ((possibleTypo, expected) <- possibleTypos) {
+              if (line.contains(possibleTypo))
+                echo(s"Warning: Possible typo in error tag in file ${file.getCanonicalPath}:$lineNbr: found `$possibleTypo` but expected `$expected`")
+            }
 
-          expectedErrors += anyposErrors + noposErrors + errors
-        }
+            expectedErrors += anyposErrors + noposErrors + errors
+          }
+        }.get
       }
 
       (errorMap, expectedErrors)

doc-tool/src/dotty/tools/dottydoc/staticsite/Site.scala

@@ -25,6 +25,7 @@ import dotc.core.Contexts.Context
 import dotc.util.SourceFile
 import model.Package
 import scala.io.{ Codec, Source }
+import scala.util.Using
 import io.{ AbstractFile, VirtualFile, File }
 import scala.collection.mutable.ArrayBuffer
 import util.syntax._
@@ -90,7 +91,7 @@ case class Site(
     root
       .listFiles
       .find(_.getName == "sidebar.yml")
-      .map("---\n" + Source.fromFile(_).mkString + "\n---")
+      .map(f => "---\n" + Using(Source.fromFile(f))(_.mkString).get + "\n---")
       .map(Yaml.apply)
       .flatMap(Sidebar.apply)
       .getOrElse(Sidebar.empty)
@@ -412,7 +413,7 @@ case class Site(
   }
 
   private def toSourceFile(f: JFile): SourceFile =
-    new SourceFile(AbstractFile.getFile(new File(f.toPath)), Source.fromFile(f, "UTF-8").toArray)
+    new SourceFile(AbstractFile.getFile(new File(f.toPath)), Using(Source.fromFile(f, "UTF-8"))(_.toArray).get)
 
   private def collectFiles(dir: JFile, includes: String => Boolean): Array[JFile] =
     dir

tests/run-custom-args/tasty-interpreter/Test.scala

@@ -7,6 +7,7 @@ import dotty.tools.dotc.util.DiffUtil
 import dotty.tools.io.Path
 
 import scala.io.Source
+import scala.util.Using
 import scala.tasty.interpreter.TastyInterpreter
 
 object Test {
@@ -89,7 +90,7 @@ object Test {
 
     val checkFile = java.nio.file.Paths.get("tests/run/" + testFileName.stripSuffix(".scala") + ".check")
     if (java.nio.file.Files.exists(checkFile)) {
-      val expectedOutput = Source.fromFile(checkFile.toFile).getLines().mkString("", "\n", "\n")
+      val expectedOutput = Using(Source.fromFile(checkFile.toFile))(_.getLines().mkString("", "\n", "\n")).get
 
       assert(expectedOutput == actualOutput,
         "\n>>>>>>>>>>>>>>>>>>\n" +