Merge pull request #4745 from eatkins/watch-fixes

Watch fixes

main/src/main/scala/sbt/Defaults.scala

@@ -154,6 +154,7 @@ object Defaults extends BuildCommon {
       inputFileStamper :== sbt.nio.FileStamper.Hash,
       outputFileStamper :== sbt.nio.FileStamper.LastModified,
       onChangedBuildSource :== sbt.nio.Keys.WarnOnSourceChanges,
+      watchTriggeredMessage :== sbt.nio.Watch.defaultOnTriggerMessage,
       watchForceTriggerOnAnyChange :== false,
       watchPersistFileStamps :== true,
       watchTriggers :== Nil,

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

@@ -27,6 +27,7 @@ import sbt.internal.nio._
 import sbt.internal.util.complete.Parser._
 import sbt.internal.util.complete.{ Parser, Parsers }
 import sbt.internal.util.{ AttributeKey, JLine, Util }
+import sbt.nio.FileStamper.LastModified
 import sbt.nio.Keys.{ fileInputs, _ }
 import sbt.nio.Watch.{ Creation, Deletion, Update }
 import sbt.nio.file.FileAttributes
@@ -531,7 +532,7 @@ private[sbt] object Continuous extends DeprecatedContinuous {
     val onEvent: Event => Seq[(Watch.Event, Watch.Action)] = event => {
       val path = event.path
 
-      def watchEvent(stamper: FileStamper, forceTrigger: Boolean): Option[Watch.Event] = {
+      def watchEvent(forceTrigger: Boolean): Option[Watch.Event] = {
         if (!event.exists) {
           Some(Deletion(event))
           fileStampCache.remove(event.path) match {
@@ -539,7 +540,7 @@ private[sbt] object Continuous extends DeprecatedContinuous {
             case _    => Some(Deletion(event))
           }
         } else {
-          fileStampCache.update(path, stamper) match {
+          fileStampCache.update(path, FileStamper.Hash) match {
             case (None, Some(_)) => Some(Creation(event))
             case (Some(_), None) => Some(Deletion(event))
             case (Some(p), Some(c)) =>
@@ -563,23 +564,37 @@ private[sbt] object Continuous extends DeprecatedContinuous {
       }
 
       if (buildGlobs.exists(_.matches(path))) {
-        watchEvent(FileStamper.Hash, forceTrigger = false).map(e => e -> Watch.Reload).toSeq
+        watchEvent(forceTrigger = false).map(e => e -> Watch.Reload).toSeq
       } else {
         configs
           .flatMap { config =>
             config
               .inputs()
-              .collectFirst {
-                case d if d.glob.matches(path) => (d.forceTrigger, true, d.fileStamper)
-              }
-              .flatMap {
-                case (forceTrigger, accepted, stamper) =>
-                  if (accepted) {
-                    watchEvent(stamper, forceTrigger).flatMap { e =>
+              .filter(_.glob.matches(path))
+              .sortBy(_.fileStamper match {
+                case FileStamper.Hash         => -1
+                case FileStamper.LastModified => 0
+              })
+              .headOption
+              .flatMap { d =>
+                val forceTrigger = d.forceTrigger
+                d.fileStamper match {
+                  // We do not update the file stamp cache because we only want hashes in that
+                  // cache or else it can mess up the external hooks that use that cache.
+                  case LastModified =>
+                    logger.debug(s"Trigger path detected $path")
+                    val watchEvent =
+                      if (!event.exists) Deletion(event)
+                      else if (fileStampCache.get(path).isDefined) Creation(event)
+                      else Update(event)
+                    val action = config.watchSettings.onFileInputEvent(count.get(), watchEvent)
+                    Some(watchEvent -> action)
+                  case _ =>
+                    watchEvent(forceTrigger).flatMap { e =>
                       val action = config.watchSettings.onFileInputEvent(count.get(), e)
                       if (action != Watch.Ignore) Some(e -> action) else None
                     }
-                  } else None
+                }
               }
           } match {
           case events if events.isEmpty => Nil
@@ -920,7 +935,7 @@ private[sbt] object Continuous extends DeprecatedContinuous {
   )(implicit e: Extracted): TriggerMessage = {
     lazy val default =
       key.get(watchTriggeredMessage).getOrElse(Watch.defaultOnTriggerMessage)
-    key.get(deprecatedWatchingMessage).map(Left(_)).getOrElse(Right(default))
+    key.get(deprecatedTriggeredMessage).map(Left(_)).getOrElse(Right(default))
   }
 
   private implicit class ScopeOps(val scope: Scope) {

main/src/main/scala/sbt/nio/FileStamp.scala

@@ -241,7 +241,7 @@ private[sbt] object FileStamp {
     def getOrElseUpdate(path: Path, stamper: FileStamper): Option[FileStamp] =
       underlying.get(path) match {
         case null     => updateImpl(path, stamper)
-        case Left(v)  => updateImpl(path, stamper)
+        case Left(_)  => updateImpl(path, stamper)
         case Right(v) => Some(v)
       }
     def remove(key: Path): Option[FileStamp] = {

sbt/src/sbt-test/watch/overlapping/build.sbt

@@ -0,0 +1,26 @@
+import java.nio.file.Files
+import java.nio.file.attribute.FileTime
+
+import sbt.nio.Watch
+
+import scala.concurrent.duration._
+
+val foo = taskKey[Unit]("foo.txt")
+foo / watchForceTriggerOnAnyChange := true
+foo / fileInputs := baseDirectory.value.toGlob / "files" / "foo.txt" :: Nil
+foo / watchTriggers := baseDirectory.value.toGlob / ** / "foo.txt" :: Nil
+foo := {
+  (foo / allInputFiles).value.foreach { p =>
+    Files.setLastModifiedTime(p, FileTime.fromMillis(Files.getLastModifiedTime(p).toMillis + 3000))
+  }
+  sbt.nio.Stamps.check(foo).value
+}
+
+watchAntiEntropy := 0.seconds
+watchOnFileInputEvent := { (count, event: Watch.Event) =>
+  assert(event.path.getFileName.toString == "foo.txt")
+  if (new String(Files.readAllBytes(event.path)) == "foo") {
+    if (count < 3) Watch.Trigger
+    else Watch.CancelWatch
+  } else new Watch.HandleError(new IllegalStateException("Wrong stamp was set"))
+}

sbt/src/sbt-test/watch/overlapping/files/foo.txt

@@ -0,0 +1 @@
+foo

sbt/src/sbt-test/watch/overlapping/project/Stamps.scala

@@ -0,0 +1,16 @@
+package sbt
+package nio
+
+import java.nio.file._
+import sbt.nio.Keys._
+
+object Stamps {
+  def check(key: TaskKey[_]): Def.Initialize[Task[Unit]] = Def.task {
+    (key / inputFileStamps).value.map {
+      case (p, FileStamp.Hash(_)) =>
+      case (p, _) =>
+        Files.write(p, "fail".getBytes)
+        throw new IllegalStateException("Got incorrect stamp: $s")
+    }
+  }
+}

sbt/src/sbt-test/watch/overlapping/test

@@ -0,0 +1 @@
+> ~foo