Change signature of pre watch methods

It makes the method parameters more clear if we pass in the ProjectRef
rather than the project name. We also don't lose information.

main/src/main/scala/sbt/internal/Continuous.scala

@@ -466,7 +466,7 @@ private[sbt] object Continuous extends DeprecatedContinuous {
   )(
       implicit extracted: Extracted
   ): Callbacks = {
-    val project = extracted.currentRef.project
+    val project = extracted.currentRef
     val logger = setLevel(rawLogger, configs.map(_.watchSettings.logLevel).min, state)
     val beforeCommand = () => configs.foreach(_.watchSettings.beforeCommand())
     val onStart: () => Watch.Action = getOnStart(project, commands, configs, rawLogger, count)
@@ -497,7 +497,7 @@ private[sbt] object Continuous extends DeprecatedContinuous {
   }
 
   private def getOnStart(
-      project: String,
+      project: ProjectRef,
       commands: Seq[String],
       configs: Seq[Config],
       logger: Logger,
@@ -900,7 +900,8 @@ private[sbt] object Continuous extends DeprecatedContinuous {
     val beforeCommand: () => Unit = key.get(watchBeforeCommand).getOrElse(() => {})
     val onFileInputEvent: WatchOnEvent =
       key.get(watchOnFileInputEvent).getOrElse(Watch.trigger)
-    val onIteration: Option[(Int, String, Seq[String]) => Watch.Action] = key.get(watchOnIteration)
+    val onIteration: Option[(Int, ProjectRef, Seq[String]) => Watch.Action] =
+      key.get(watchOnIteration)
     val onTermination: Option[(Watch.Action, String, Int, State) => State] =
       key.get(watchOnTermination)
     val startMessage: StartMessage = getStartMessage(key)

main/src/main/scala/sbt/internal/DeprecatedContinuous.scala

@@ -10,14 +10,14 @@ package sbt.internal
 import java.nio.file.Path
 import java.util.concurrent.atomic.AtomicReference
 
-import sbt.{ State, Watched }
+import sbt.{ ProjectRef, State, Watched }
 import sbt.internal.io.{ EventMonitor, Source, WatchState => WS }
 import sbt.internal.util.AttributeKey
 import sbt.nio.file.Glob
 
 private[internal] trait DeprecatedContinuous {
   protected type StartMessage =
-    Option[Either[WS => String, (Int, String, Seq[String]) => Option[String]]]
+    Option[Either[WS => String, (Int, ProjectRef, Seq[String]) => Option[String]]]
   protected type TriggerMessage = Either[WS => String, (Int, Path, Seq[String]) => Option[String]]
   protected type DeprecatedWatchState = WS
   protected val deprecatedWatchingMessage = sbt.Keys.watchingMessage

main/src/main/scala/sbt/nio/Keys.scala

@@ -18,7 +18,7 @@ import sbt.internal.nio.FileTreeRepository
 import sbt.internal.util.AttributeKey
 import sbt.internal.util.complete.Parser
 import sbt.nio.file.{ ChangedFiles, FileAttributes, FileTreeView, Glob }
-import sbt.{ Def, InputKey, State, StateTransform }
+import sbt.{ Def, InputKey, ProjectRef, State, StateTransform }
 
 import scala.concurrent.duration.FiniteDuration
 
@@ -88,7 +88,7 @@ object Keys {
   val watchOnFileInputEvent = settingKey[(Int, Watch.Event) => Watch.Action](
     "Callback to invoke if an event is triggered in a continuous build by one of the files matching an fileInput glob for the task and its transitive dependencies"
   ).withRank(DSetting)
-  val watchOnIteration = settingKey[(Int, String, Seq[String]) => Watch.Action](
+  val watchOnIteration = settingKey[(Int, ProjectRef, Seq[String]) => Watch.Action](
     "Function that is invoked before waiting for file system events or user input events."
   ).withRank(DSetting)
   val watchOnTermination = settingKey[(Watch.Action, String, Int, State) => State](
@@ -97,7 +97,7 @@ object Keys {
   val watchPersistFileStamps = settingKey[Boolean](
     "Toggles whether or not the continuous build will reuse the file stamps computed in previous runs. Setting this to true decrease watch startup latency but could cause inconsistent results if many source files are concurrently modified."
   ).withRank(DSetting)
-  val watchStartMessage = settingKey[(Int, String, Seq[String]) => Option[String]](
+  val watchStartMessage = settingKey[(Int, ProjectRef, Seq[String]) => Option[String]](
     "The message to show when triggered execution waits for sources to change. The parameters are the current watch iteration count, the current project name and the tasks that are being run with each build."
   ).withRank(DSetting)
   // The watchTasks key should really be named watch, but that is already taken by the deprecated watch key. I'd be surprised if there are any plugins that use it so I think we should consider breaking binary compatibility to rename this task.

main/src/main/scala/sbt/nio/Watch.scala

@@ -401,19 +401,19 @@ object Watch {
     )
     s"Options:\n${opts.mkString("  ", "\n  ", "")}"
   }
-  private def waitMessage(project: String, commands: Seq[String]): String = {
+  private def waitMessage(project: ProjectRef, commands: Seq[String]): String = {
     val plural = if (commands.size > 1) "s" else ""
     val cmds = commands.mkString("; ")
     s"Monitoring source files for updates...\n" +
-      s"Project: $project\nCommand$plural: $cmds\n$options"
+      s"Project: ${project.project}\nCommand$plural: $cmds\n$options"
   }
 
   /**
    * A function that prints out the current iteration count and gives instructions for exiting
    * or triggering the build.
    */
-  val defaultStartWatch: (Int, String, Seq[String]) => Option[String] = {
-    (count: Int, project: String, commands: Seq[String]) =>
+  val defaultStartWatch: (Int, ProjectRef, Seq[String]) => Option[String] = {
+    (count: Int, project: ProjectRef, commands: Seq[String]) =>
       Some(s"$count. ${waitMessage(project, commands)}")
   }.label("Watched.defaultStartWatch")
 

sbt/src/sbt-test/watch/input-parser/project/Build.scala

@@ -25,12 +25,12 @@ object Build {
   // Note that the order is byeParser | helloParser. In general, we want the higher priority
   // action to come first because otherwise we would potentially scan past it.
   val helloOrByeParser: Parser[Watch.Action] = byeParser | helloParser
-  val alternativeStartMessage: (Int, String, Seq[String]) => Option[String] = { (_, _, _) =>
+  val alternativeStartMessage: (Int, ProjectRef, Seq[String]) => Option[String] = { (_, _, _) =>
     outputStream.write("xybyexyblahxyhelloxy".getBytes)
     outputStream.flush()
     Some("alternative start message")
   }
-  val otherAlternativeStartMessage: (Int, String, Seq[String]) => Option[String] = { (_, _, _) =>
+  val otherAlternativeStartMessage: (Int, ProjectRef, Seq[String]) => Option[String] = { (_, _, _) =>
     outputStream.write("xyhellobyexyblahx".getBytes)
     outputStream.flush()
     Some("other alternative start message")