Pluggable loggers for sbt-coursier (#872)

cache/jvm/src/main/scala/coursier/Cache.scala

@@ -1165,7 +1165,20 @@ object Cache {
     def gettingLength(url: String): Unit = {}
     def gettingLengthResult(url: String, length: Option[Long]): Unit = {}
 
-    def removedCorruptFile(url: String, file: File, reason: Option[FileError]): Unit
+    def removedCorruptFile(url: String, file: File, reason: Option[FileError]): Unit = {}
+
+    /***
+     *
+     * @param beforeOutput: called before any output is printed, iff something else is outputed.
+     *                      (That is, if that `Logger` doesn't print any progress,
+     *                      `initialMessage` won't be printed either.)
+     */
+    def init(beforeOutput: => Unit): Unit = {}
+    /**
+      *
+      * @return whether any message was printed by `Logger`
+      */
+    def stopDidPrintSomething(): Boolean = false
   }
 
   var bufferSize = 1024*1024

cache/jvm/src/main/scala/coursier/TermDisplay.scala

@@ -410,13 +410,7 @@ class TermDisplay(
     else
       1000L / 60
 
-  /***
-    *
-    * @param beforeOutput: called before any output is printed, iff something else is outputed.
-    *                      (That is, if that `TermDisplay` doesn't print any progress,
-    *                      `initialMessage` won't be printed either.)
-    */
-  def init(beforeOutput: => Unit): Unit = {
+  override def init(beforeOutput: => Unit): Unit = {
     updateRunnableOpt = Some(new UpdateDisplayRunnable(beforeOutput, out, width, fallbackMode0))
 
     updateRunnable.init()
@@ -426,11 +420,7 @@ class TermDisplay(
   def init(): Unit =
     init(())
 
-  /**
-    *
-    * @return whether any message was printed by this `TermDisplay`
-    */
-  def stopDidPrintSomething(): Boolean = {
+  override def stopDidPrintSomething(): Boolean = {
     scheduler.shutdown()
     scheduler.awaitTermination(2 * refreshInterval, TimeUnit.MILLISECONDS)
     updateRunnable.stop()

sbt-coursier/src/main/scala/coursier/CoursierPlugin.scala

@@ -1,5 +1,6 @@
 package coursier
 
+import java.io.OutputStreamWriter
 import sbt.librarymanagement._
 import sbt.{ Configuration, Resolver, _ }
 import sbt.Keys._
@@ -52,6 +53,8 @@ object CoursierPlugin extends AutoPlugin {
     val coursierClassifiersArtifacts = Keys.coursierClassifiersArtifacts
     val coursierSbtClassifiersArtifacts = Keys.coursierSbtClassifiersArtifacts
 
+    val coursierLoggerFactory = Keys.coursierLoggerFactory
+
     val coursierVersion = coursier.util.Properties.version
     val addSbtCoursier = {
       addSbtPlugin("io.get-coursier" % "sbt-coursier" % coursierVersion)
@@ -306,7 +309,8 @@ object CoursierPlugin extends AutoPlugin {
     coursierCredentials := Map.empty,
     coursierCache := Cache.default,
     coursierReorderResolvers := true,
-    coursierKeepPreloaded := false
+    coursierKeepPreloaded := false,
+    coursierLoggerFactory := { () => new TermDisplay(new OutputStreamWriter(System.err)) }
   )
 
   override lazy val projectSettings = coursierSettings(None, Seq(Compile, Test).map(c => c -> c.name)) ++

sbt-coursier/src/main/scala/coursier/Keys.scala

@@ -17,6 +17,7 @@ object Keys {
   val coursierCachePolicies = SettingKey[Seq[CachePolicy]]("coursier-cache-policies")
   val coursierTtl = SettingKey[Option[Duration]]("coursier-ttl")
   val coursierKeepPreloaded = SettingKey[Boolean]("coursier-keep-preloaded", "Whether to take into account sbt preloaded repositories or not")
+  val coursierLoggerFactory = SettingKey[() => Cache.Logger]("coursier-logger-factory")
 
   val coursierVerbosity = SettingKey[Int]("coursier-verbosity")
 

sbt-coursier/src/main/scala/coursier/Tasks.scala

@@ -431,8 +431,6 @@ object Tasks {
       Module(scalaOrganization, "scalap") -> scalaVersion
     )
 
-  private def createLogger() = new TermDisplay(new OutputStreamWriter(System.err))
-
   private[coursier] def exceptionPatternParser(): String => coursier.ivy.Pattern = {
 
     val props = sys.props.toMap
@@ -571,7 +569,6 @@ object Tasks {
   def resolutionsTask(
     sbtClassifiers: Boolean = false
   ): Def.Initialize[sbt.Task[Map[Set[String], coursier.Resolution]]] = Def.taskDyn {
-
     val projectName = thisProjectRef.value.project
 
     val sv = scalaVersion.value
@@ -605,6 +602,7 @@ object Tasks {
     val cachePolicies = coursierCachePolicies.value
     val ttl = coursierTtl.value
     val cache = coursierCache.value
+    val createLogger = coursierLoggerFactory.value
 
     val log = streams.value.log
 
@@ -692,7 +690,7 @@ object Tasks {
       def resolution(startRes: Resolution) = {
 
         var pool: ExecutorService = null
-        var resLogger: TermDisplay = null
+        var resLogger: Cache.Logger = null
 
         val printOptionalMessage = verbosityLevel >= 0 && verbosityLevel <= 1
 
@@ -954,7 +952,6 @@ object Tasks {
     ignoreArtifactErrors: Boolean = false,
     includeSignatures: Boolean = false
   ) = Def.taskDyn {
-
     val projectName = thisProjectRef.value.project
 
     val parallelDownloads = coursierParallelDownloads.value
@@ -962,6 +959,7 @@ object Tasks {
     val cachePolicies = coursierCachePolicies.value
     val ttl = coursierTtl.value
     val cache = coursierCache.value
+    val createLogger = coursierLoggerFactory.value
 
     val log = streams.value.log
 
@@ -1007,7 +1005,7 @@ object Tasks {
       synchronized {
 
         var pool: ExecutorService = null
-        var artifactsLogger: TermDisplay = null
+        var artifactsLogger: Cache.Logger = null
 
         val printOptionalMessage = verbosityLevel >= 0 && verbosityLevel <= 1
 

sbt-coursier/src/sbt-test/sbt-coursier/logger/build.sbt

@@ -0,0 +1,68 @@
+val logFile = settingKey[File]("")
+
+// Arbitrary dependency with no transitive dependencies
+libraryDependencies += "org.slf4j" % "slf4j-api" % "1.7.25"
+// We want to control when the cache gets a hit
+coursierCache := baseDirectory.value / "cache"
+logFile := baseDirectory.value / "log"
+
+coursierLoggerFactory := {
+  val logStream = new java.io.PrintStream(logFile.value)
+  def log(msg: String): Unit = {
+    println(msg)
+    logStream.println(msg)
+  }
+  val cacheFile = coursierCache.value
+  ;{ () =>
+    new coursier.Cache.Logger {
+      override def init(beforeOutput: => Unit): Unit = {
+        beforeOutput
+        log("init")
+      }
+      override def foundLocally(url: String, file: File): Unit = {
+        log(s"found $url at ${IO.relativize(cacheFile, file).getOrElse(file)}")
+      }
+      override def downloadingArtifact(url: String, file: File): Unit = {
+        log(s"downloading $url to ${IO.relativize(cacheFile, file).getOrElse(file)}")
+      }
+      override def downloadedArtifact(url: String, success: Boolean): Unit = {
+        log(s"downloaded $url: $success")
+      }
+      override def stopDidPrintSomething(): Boolean = {
+        log("stop")
+        true
+      }
+    }
+  }
+}
+
+TaskKey[Unit]("checkDownloaded") := {
+  val log = IO.readLines(logFile.value)
+  if (log.head != "init") {
+    sys.error(s"log started with '${log.head}', not init")
+  }
+  if (log.last != "stop") {
+    sys.error(s"log ended with '${log.last}', not stop")
+  }
+  val url = "https://repo1.maven.org/maven2/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.jar"
+  val downloadedMsg = s"downloaded $url: true"
+  val downloadingMsgStart = s"downloading $url to "
+  if (!log.contains(downloadedMsg))
+    sys.error(s"log doesn't contain '$downloadedMsg'")
+  if (!log.exists(_.startsWith(downloadingMsgStart)))
+    sys.error(s"log doesn't contain line starting with '$downloadingMsgStart'")
+}
+
+TaskKey[Unit]("checkFound") := {
+  val log = IO.readLines(logFile.value)
+  if (log.head != "init") {
+    sys.error(s"log started with '${log.head}', not init")
+  }
+  if (log.last != "stop") {
+    sys.error(s"log ended with '${log.last}', not stop")
+  }
+  val url = "https://repo1.maven.org/maven2/org/slf4j/slf4j-api/1.7.25/slf4j-api-1.7.25.jar"
+  val msg = s"found $url at "
+  if (!log.exists(_.startsWith(msg)))
+    sys.error(s"log doesn't contain line starting with '$msg'")
+}

sbt-coursier/src/sbt-test/sbt-coursier/logger/project/plugins.sbt

@@ -0,0 +1,11 @@
+{
+  val pluginVersion = sys.props.getOrElse(
+    "plugin.version",
+    throw new RuntimeException(
+      """|The system property 'plugin.version' is not defined.
+         |Specify this property using the scriptedLaunchOpts -D.""".stripMargin
+    )
+  )
+
+  addSbtPlugin("io.get-coursier" % "sbt-coursier" % pluginVersion)
+}

sbt-coursier/src/sbt-test/sbt-coursier/logger/test

@@ -0,0 +1,6 @@
+$ delete cache
+> update
+> checkDownloaded
+> reload
+> update
+> checkFound