Overrride evicted task #170

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

@@ -162,6 +162,7 @@ object CoursierPlugin extends AutoPlugin {
       withClassifiers = true,
       sbtClassifiers = true
     ).value,
+    evicted := EvictedTasks.evictedTask().value,
     coursierConfigGraphs := InputsTasks.ivyGraphsTask.value,
     coursierSbtClassifiersModule := classifiersModule.in(updateSbtClassifiers).value,
     coursierConfigurations := InputsTasks.coursierConfigurationsTask(None).value,

modules/sbt-coursier/src/main/scala/coursier/sbtcoursier/EvictedTasks.scala

@@ -0,0 +1,92 @@
+package coursier.sbtcoursier
+
+import coursier.core.{Configuration, Dependency}
+import coursier.sbtcoursier.CoursierPlugin.autoImport.coursierResolutions
+import sbt.{Def, EvictionWarning, Task}
+import sbt.Keys._
+
+object EvictedTasks {
+
+  def evictedTask(): Def.Initialize[Task[EvictionWarning]] =
+    Def.task {
+      val log = streams.value.log
+
+      val resolution = coursierResolutions.value
+        .filter(_._1.contains(Configuration("compile")))
+        .head
+        ._2
+
+      def isEvicted(dependency: Dependency): Boolean =
+        resolution.finalDependenciesCache.keys.exists { finalDependency =>
+          dependency.module == finalDependency.module && dependency.version != finalDependency.version
+        }
+
+      def findAllVersions(dependency: Dependency): Set[String] =
+        resolution.finalDependenciesCache.keys
+          .filter(_.module == dependency.module)
+          .map(_.version)
+          .toSet
+
+      def findLatestVersion(dependency: Dependency): String =
+        resolution.dependencies
+          .find(_.module == dependency.module)
+          .map(_.version)
+          .getOrElse("(unknown)") // this should never happen actually
+
+      def findReverseDeps(dependency: Dependency): Seq[(Dependency, String)] =
+        resolution.reverseDependencies
+          .filterKeys(_.module == dependency.module)
+          .toSeq
+          .flatMap { t =>
+            t._2.map(d => (d, d.version + " => " + t._1.version))
+          }
+          .distinct
+
+      // evicted deps and all their versions
+      val evictedDeps: Map[Dependency, Set[String]] =
+        resolution.rootDependencies
+          .filter(isEvicted)
+          .map { rootDep =>
+            (rootDep, findAllVersions(rootDep))
+          }
+          .toMap
+
+      // TODO Returns 0 conflicts, investigate
+      /*
+      val conflicts: Seq[Conflict] = Conflict(resolution)
+      if(conflicts.nonEmpty) {
+        log.warn(
+          s"Found version conflict(s) in library dependencies; some are suspected to be binary incompatible:")
+        conflicts.foreach { conflict =>
+          log.warn(s"""Using ${conflict.module}:${conflict.version} over ${conflict.wantedVersion}
+                      |(wanted by ${conflict.dependeeModule}:${conflict.dependeeVersion})""".stripMargin)
+        }
+      }
+       */
+
+      if (evictedDeps.nonEmpty) {
+        log.warn(
+          s"Found version conflict(s) in library dependencies; some are suspected to be binary incompatible:")
+        evictedDeps.foreach { evictedDep =>
+          log.warn(s"  *: ${evictedDep._1.module}:${findLatestVersion(
+            evictedDep._1)} (${evictedDep._2.mkString(", ")})")
+          findReverseDeps(evictedDep._1).foreach { reverse =>
+            log.warn(
+              s"      +- ${reverse._1.module}:${reverse._1.version} (depends on ${reverse._2})")
+          }
+        }
+      }
+
+      EvictionWarning(
+        dependencyResolution.value.moduleDescriptor(
+          projectID.value,
+          Vector(),
+          scalaModuleInfo.value
+        ),
+        (evictionWarningOptions in evicted).value,
+        update.value,
+        log
+      )
+    }
+
+}

modules/sbt-coursier/src/sbt-test/sbt-coursier/evicted/build.sbt

@@ -0,0 +1,9 @@
+scalaVersion := "2.11.8"
+
+libraryDependencies ++= {
+  sys.props("sbt.log.noformat") = "true" // disables colors in coursierWhatDependsOn output
+  Seq(
+    "org.typelevel" %% "cats-effect" % "1.3.1",
+    "org.typelevel" %% "cats-core" % "1.5.0"
+  )
+}

modules/sbt-coursier/src/sbt-test/sbt-coursier/evicted/project/plugins.sbt

@@ -0,0 +1,13 @@
+addSbtPlugin {
+
+  val name = sys.props.getOrElse(
+    "plugin.name",
+    sys.error("plugin.name Java property not set")
+  )
+  val version = sys.props.getOrElse(
+    "plugin.version",
+    sys.error("plugin.version Java property not set")
+  )
+
+  "io.get-coursier" % name % version
+}

modules/sbt-coursier/src/sbt-test/sbt-coursier/evicted/test

@@ -0,0 +1 @@
+> evicted