fix usage of scalafix via another task

Regression of 0cf5501: initial (cold) invocations to a task delegating
to scalafix would result in scalafix being called before compilation
(because scalafixRunExplicitly == false) causing false negatives.

src/main/scala/scalafix/sbt/ScalafixPlugin.scala

@@ -100,9 +100,7 @@ object ScalafixPlugin extends AutoPlugin {
  compile := Def.taskDyn {
  val oldCompile =
  compile.value // evaluated first, before the potential scalafix evaluation
- val runScalafixAfterCompile =
- scalafixOnCompile.value && !scalafixRunExplicitly.value
- if (runScalafixAfterCompile)
+ if (scalafixOnCompile.value)
  scalafix
  .toTask("")
  .map(_ => oldCompile)
@@ -415,7 +413,7 @@ object ScalafixPlugin extends AutoPlugin {
  ).findErrors(files, dependencies, withScalaInterface)
  if (errors.isEmpty) {
  val task = Def.task {
- // passively consume compilation output without triggering compile as it can result in a cyclic dependency
+ // don't use fullClasspath as it results in a cyclic dependency via compile when scalafixOnCompile := true
  val classpath =
  dependencyClasspath.in(config).value.map(_.data.toPath) :+
  classDirectory.in(config).value.toPath
@@ -428,8 +426,8 @@ object ScalafixPlugin extends AutoPlugin {
  streams.in(config, scalafix).value
  )
  }
- if (scalafixRunExplicitly.value) task.dependsOn(compile.in(config))
- else task
+ // sub-task of compile after which bytecode should not be modified
+ task.dependsOn(manipulateBytecode.in(config))
  } else {
  Def.task {
  if (errors.length == 1) {
@@ -563,16 +561,6 @@ object ScalafixPlugin extends AutoPlugin {
  }
  }
 
- // Controls whether scalafix should depend on compile (true) & whether compile may depend on
- // scalafix (false), to avoid cyclic dependencies causing deadlocks during executions (as
- // dependencies come from dynamic tasks).
- private val scalafixRunExplicitly: Def.Initialize[Task[Boolean]] =
- Def.task {
- executionRoots.value.exists { root =>
- Seq(scalafix.key, scalafixAll.key).contains(root.key)
- }
- }
-
  private def isScalaFile(file: File): Boolean = {
  val path = file.getPath
  path.endsWith(".scala") ||

src/sbt-test/sbt-scalafix/wrapper/.scalafix.conf

@@ -0,0 +1 @@
+rules = [RemoveUnused]

src/sbt-test/sbt-scalafix/wrapper/build.sbt

@@ -0,0 +1,5 @@
+val V = _root_.scalafix.sbt.BuildInfo
+
+scalaVersion := V.scala212
+addCompilerPlugin(scalafixSemanticdb)
+scalacOptions ++= Seq("-Yrangepos", "-Ywarn-unused")

src/sbt-test/sbt-scalafix/wrapper/project/LintAllPlugin.scala

@@ -0,0 +1,24 @@
+import sbt._
+import scalafix.sbt.ScalafixPlugin
+import scalafix.sbt.ScalafixPlugin.autoImport._
+
+object LintAllPlugin extends AutoPlugin {
+
+ override def trigger: PluginTrigger = allRequirements
+
+ override def requires: Plugins = ScalafixPlugin
+
+ object autoImport {
+ val lintAll = taskKey[Unit]("run all linters")
+ }
+
+ import autoImport._
+
+ override def projectSettings: Seq[Def.Setting[_]] =
+ Seq(
+ lintAll := {
+ scalafixAll.toTask(" --check").value
+ // & other linters...
+ }
+ )
+}

src/sbt-test/sbt-scalafix/wrapper/project/plugins.sbt

@@ -0,0 +1,2 @@
+resolvers += Resolver.sonatypeRepo("public")
+addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % sys.props("plugin.version"))

src/sbt-test/sbt-scalafix/wrapper/src/main/scala/example/Example.scala

@@ -0,0 +1,5 @@
+package example
+
+import imported.Imported
+
+object Example

src/sbt-test/sbt-scalafix/wrapper/src/main/scala/imported/Imported.scala

@@ -0,0 +1,3 @@
+package imported
+
+object Imported

src/sbt-test/sbt-scalafix/wrapper/test

@@ -0,0 +1,14 @@
+# check that missing rewrites are detected, with or without a warm compilation cache
+> set scalafixOnCompile := false
+-> lintAll
+> compile
+-> lintAll
+
+# apply the rewrite via an explicit call
+> scalafix
+
+# confirms that `lintAll` sees that rewrite, with or without a warm compilation cache
+> clean
+> lintAll
+> compile
+> lintAll