Fix #3007: Add support for initial and cleanup command in the REPL

Author: SzymonPajzert

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

@@ -27,6 +27,7 @@ import org.jline.reader._
 import scala.annotation.tailrec
 import scala.collection.JavaConverters._
 
+
 /** The state of the REPL contains necessary bindings instead of having to have
  *  mutation
  *
@@ -70,7 +71,7 @@ class ReplDriver(settings: Array[String],
   }
 
   /** the initial, empty state of the REPL session */
-  protected[this] def initState = State(0, 0, Nil, rootCtx)
+  final def initialState = State(0, 0, Nil, rootCtx)
 
   /** Reset state of repl to the initial state
    *
@@ -101,7 +102,7 @@ class ReplDriver(settings: Array[String],
    *  observable outside of the CLI, for this reason, most helper methods are
    *  `protected final` to facilitate testing.
    */
-  final def runUntilQuit(): State = {
+  final def runUntilQuit(initialState: State = initialState): State = {
     val terminal = new JLineTerminal()
 
     /** Blockingly read a line, getting back a parse result */
@@ -127,7 +128,7 @@ class ReplDriver(settings: Array[String],
       else loop(interpret(res)(state))
     }
 
-    try withRedirectedOutput { loop(initState) }
+    try withRedirectedOutput { loop(initialState) }
     finally terminal.close()
   }
 
@@ -136,6 +137,9 @@ class ReplDriver(settings: Array[String],
     interpret(parsed)
   }
 
+  // TODO: i5069
+  final def bind(name: String, value: Any)(implicit state: State): State = state
+
   private def withRedirectedOutput(op: => State): State =
     Console.withOut(out) { Console.withErr(out) { op } }
 
@@ -308,7 +312,7 @@ class ReplDriver(settings: Array[String],
 
     case Reset =>
       resetToInitial()
-      initState
+      initialState
 
     case Imports =>
       state.imports.foreach(i => out.println(SyntaxHighlighting(i.show(state.context))))

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

@@ -32,7 +32,7 @@ class ReplTest private (out: ByteArrayOutputStream) extends ReplDriver(
     storedOutput()
 
   def fromInitialState[A](op: State => A): A =
-    op(initState)
+    op(initialState)
 
   implicit class TestingState(state: State) {
     def andThen[A](op: State => A): A = op(state)

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

@@ -65,7 +65,7 @@ class ScriptedTests extends ReplTest with MessageRendering {
       resetToInitial()
       val inputRes = extractInputs(prompt)
       val buf = new ArrayBuffer[String]
-      inputRes.foldLeft(initState) { (state, input) =>
+      inputRes.foldLeft(initialState) { (state, input) =>
         val (out, nstate) = evaluate(state, input, prompt)
         buf.append(out)
         nstate

sbt-bridge/src/xsbt/ConsoleInterface.scala

@@ -19,24 +19,6 @@ class ConsoleInterface {
   def run(args: Array[String],
           bootClasspathString: String,
           classpathString: String,
-          // TODO: initial commands needs to be run under some form of special
-          // "silent" mode in the REPL. I.e. the effects should be had without
-          // any visual output.
-          //
-          // To do this we can use the `run` interface to the `ReplDriver` and
-          // pass it a special instance of `ParseResult` like `Silently(res: ParseResult)`
-          // and then observe the effects without printing to `ReplDriver#out`
-          //
-          // This way, the REPL can offer feedback on invalid commands but
-          // still function without stringly logic.
-          //
-          // This same principle can be applied to `cleanupCommands` and
-          // `bindValues`
-          //
-          // Steps:
-          //
-          // 1. Introduce `case class Silent(res: ParseResult) extends ParseResult`
-          // 2. Perform all steps in `interpret` as usual without printing to `out`
           initialCommands: String,
           cleanupCommands: String,
           loader: ClassLoader,
@@ -51,6 +33,15 @@ class ConsoleInterface {
       } ++
       Array("-classpath", classpathString)
 
-    new ReplDriver(completeArgs, classLoader = Some(loader)).runUntilQuit()
+    val driver = new ReplDriver(completeArgs, classLoader = Some(loader))
+
+    val s0 = (bindNames, bindValues).zipped.foldLeft(driver.initialState) {
+      case (state, (name, value)) => driver.bind(name, value)(state)
+    }
+
+    val s1 = driver.run(initialCommands)(s0)
+    // TODO handle failure during initialisation
+    val s2 = driver.runUntilQuit(s1)
+    driver.run(cleanupCommands)(s2)
   }
 }