Fix a REPL issue while parsing empty trees (e.g. ;)

Author: allanrenucci

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

@@ -146,7 +146,7 @@ class ReplCompiler(val directory: AbstractFile) extends Compiler {
    *  }
    *  ```
    */
-  def wrapped(defs: Definitions): untpd.PackageDef = {
+  def wrapped(defs: Definitions, sourceCode: String): untpd.PackageDef = {
     import untpd._
 
     implicit val ctx: Context = defs.state.run.runContext
@@ -156,7 +156,7 @@ class ReplCompiler(val directory: AbstractFile) extends Compiler {
       List(
         ModuleDef(objectName(defs.state), tmpl)
           .withMods(new Modifiers(Module | Final))
-          .withPos(Position(defs.stats.head.pos.start, defs.stats.last.pos.end))
+          .withPos(Position(0, sourceCode.length))
       )
     }
 
@@ -170,7 +170,7 @@ class ReplCompiler(val directory: AbstractFile) extends Compiler {
 
   def createUnit(defs: Definitions, sourceCode: String): Result[CompilationUnit] = {
     val unit = new CompilationUnit(new SourceFile(objectName(defs.state).toString, sourceCode))
-    unit.untpdTree = wrapped(defs)
+    unit.untpdTree = wrapped(defs, sourceCode)
     unit.result
   }
 

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

@@ -186,7 +186,7 @@ class ReplDriver(settings: Array[String],
 
   private def interpret(res: ParseResult)(implicit state: State): State =
     res match {
-      case parsed: Parsed =>
+      case parsed: Parsed if parsed.trees.nonEmpty =>
         compile(parsed)
           .withHistory(parsed.sourceCode :: state.history)
           .newRun(compiler, rootCtx)
@@ -195,9 +195,13 @@ class ReplDriver(settings: Array[String],
         displayErrors(errs)
         state.withHistory(src :: state.history)
 
-      case Newline | SigKill => state
-
       case cmd: Command => interpretCommand(cmd)
+
+      case SigKill => // TODO
+        state
+
+      case _ => // new line, empty tree
+        state
     }
 
   /** Compile `parsed` trees and evolve `state` in accordance */

compiler/test-resources/repl/parsing

@@ -0,0 +1,14 @@
+scala> ; 
+scala> ;; 
+scala> 1; 2 
+val res0: Int = 1
+val res1: Int = 2
+scala> 1; 
+val res2: Int = 1
+scala> 1;; 2 
+val res3: Int = 1
+val res4: Int = 2
+scala> } 
+1 | }
+  | ^
+  | eof expected, but '}' found

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

@@ -44,7 +44,7 @@ class ScriptedTests extends ReplTest with MessageRendering {
     def evaluate(state: State, input: String, prompt: String) =
       try {
         val nstate = run(input.drop(prompt.length))(state)
-        val out = input + "\n" + stripColor(storedOutput())
+        val out = input + "\n" + storedOutput()
         (out, nstate)
       }
       catch {