Restore original reporter after compilation

plugin/src/main/scala/com/softwaremill/clippy/ClippyPlugin.scala

@@ -54,7 +54,7 @@ class ClippyPlugin(val global: Global) extends Plugin {
     }
   }
 
-  override val components: List[PluginComponent] = List(new InjectReporter(handleError, global))
+  override val components: List[PluginComponent] = List(new InjectReporter(handleError, global), new RestoreReporter(global))
 
   private def prettyPrintTypeMismatchError(tme: TypeMismatchError[ExactT], msg: String): String = {
     val plain = new StringDiff(tme.required.toString, tme.found.toString)

plugin/src/main/scala/com/softwaremill/clippy/InjectReporter.scala

@@ -4,6 +4,9 @@ import scala.reflect.internal.util.Position
 import scala.tools.nsc.plugins.PluginComponent
 import scala.tools.nsc.{Global, Phase}
 
+/**
+  * Responsible for replacing the global reporter with our custom Clippy reporter after the first phase of compilation.
+  */
 class InjectReporter(handleError: (Position, String) => String, superGlobal: Global) extends PluginComponent {
 
   override val global = superGlobal

plugin/src/main/scala/com/softwaremill/clippy/RestoreReporter.scala

@@ -0,0 +1,30 @@
+package com.softwaremill.clippy
+
+import scala.tools.nsc.plugins.PluginComponent
+import scala.tools.nsc.{Global, Phase}
+
+/**
+  * Replaces global reporter back with the original global reporter. Sbt uses its own xsbt.DelegatingReporter
+  * which we cannot replace outside of Scala compilation phases. This component makes sure that before the compilation
+  * is over, original reporter gets reassigned to the global field.
+  */
+class RestoreReporter(val global: Global) extends PluginComponent {
+
+  val originalReporter = global.reporter
+
+  override val runsAfter = List[String]("jvm")
+  override val runsBefore = List[String]("terminal")
+  override val phaseName = "restore-original-reporter"
+
+  override def newPhase(prev: Phase) = new Phase(prev) {
+
+    override def name = phaseName
+
+    override def description = "Switches the reporter from Clippy's DelegatingReporter back to original one"
+
+    override def run(): Unit = {
+      global.reporter = originalReporter
+    }
+  }
+
+}