Proper fix for settings color in QuotedDriver

Author: Tobias Bordenca

compiler/src/dotty/tools/dotc/quoted/QuoteDriver.scala

@@ -2,7 +2,7 @@ package dotty.tools.dotc.quoted
 
 import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.Driver
-import dotty.tools.dotc.core.Contexts.{Context, ContextBase}
+import dotty.tools.dotc.core.Contexts.{Context, ContextBase, FreshContext}
 import dotty.tools.dotc.tastyreflect.TastyImpl
 import dotty.tools.io.{AbstractFile, Directory, PlainDirectory, VirtualDirectory}
 import dotty.tools.repl.AbstractFileClassLoader
@@ -27,7 +27,7 @@ class QuoteDriver extends Driver {
     }
 
     val (_, ctx0: Context) = setup(settings.compilerArgs.toArray :+ "dummy.scala", initCtx.fresh)
-    val ctx = ctx0.fresh.setSetting(ctx0.settings.outputDir, outDir)
+    val ctx = setColor(ctx0.fresh.setSetting(ctx0.settings.outputDir, outDir), settings)
 
     val driver = new QuoteCompiler
     driver.newRun(ctx).compileExpr(expr)
@@ -50,7 +50,7 @@ class QuoteDriver extends Driver {
   }
 
   def withTree[T](expr: Expr[_], f: (Tree, Context) => T, settings: Toolbox.Settings): T = {
-    val (_, ctx: Context) = setup(settings.compilerArgs.toArray :+ "dummy.scala", initCtx.fresh)
+    val ctx = setColor(setup(settings.compilerArgs.toArray :+ "dummy.scala", initCtx.fresh)._2.fresh, settings)
 
     var output: Option[T] = None
     def registerTree(tree: tpd.Tree)(ctx: Context): Unit = {
@@ -79,6 +79,9 @@ class QuoteDriver extends Driver {
     ictx
   }
 
+  private def setColor(ctx: FreshContext, settings: Toolbox.Settings): FreshContext =
+    ctx.setSetting(ctx.settings.color, if (settings.color) "always" else "never")
+
 }
 
 object QuoteDriver {

library/src/scala/quoted/Toolbox.scala

@@ -32,7 +32,7 @@ object Toolbox {
   }
 
   /** Setting of the Toolbox instance. */
-  class Settings private (val outDir: Option[String], val showRawTree: Boolean, val compilerArgs: List[String])
+  class Settings private (val outDir: Option[String], val showRawTree: Boolean, val compilerArgs: List[String], val color: Boolean)
 
   object Settings {
 
@@ -49,10 +49,8 @@ object Toolbox {
       showRawTree: Boolean = false,
       outDir: Option[String] = None,
       compilerArgs: List[String] = Nil
-    ): Settings = {
-      val colorArg = if (color) "-color:always" else "-color:never"
-      new Settings(outDir, showRawTree, colorArg :: compilerArgs)
-    }
+    ): Settings =
+      new Settings(outDir, showRawTree, compilerArgs, color)
   }
 
   class ToolboxNotFoundException(msg: String, cause: ClassNotFoundException) extends Exception(msg, cause)