Redefine definedTests in terms of the task itself to work correctly…

… with other plugins which may redefine the task

src/plugin/src/main/scala/com/github/sbt/junit/jupiter/sbt/JupiterPlugin.scala

@@ -80,8 +80,13 @@ object JupiterPlugin extends AutoPlugin {
    * By default this is applied to the Test configuration only.
    */
   def scopedSettings: Seq[Def.Setting[_]] = Seq(
-
-    definedTests := collectTests.value
+    definedTests := Def.taskDyn {
+      val otherTests = definedTests.value
+      Def.task {
+        val jupiterTests = collectTests.value
+        otherTests ++ jupiterTests
+      }
+    }.value
   )
 
   /*
@@ -93,14 +98,12 @@ object JupiterPlugin extends AutoPlugin {
   )
 
   /*
-   * Collects available tests through JUnit Jupiter's discovery mechanism and
-   * combines them with the result of sbt.Keys.definedTests.
+   * Collects available tests through JUnit Jupiter's discovery mechanism.
    */
-  private def collectTests = Def.task {
+  private def collectTests: Def.Initialize[Task[Seq[TestDefinition]]] = Def.task {
 
     val classes = classDirectory.value
     val classpath = dependencyClasspath.value.map(_.data.toURI.toURL).toArray :+ classes.toURI.toURL
-    val result = Defaults.detectTests.value
 
     val collector = new JupiterTestCollector.Builder()
       .withClassDirectory(classes)
@@ -118,7 +121,7 @@ object JupiterPlugin extends AutoPlugin {
       }
     }
 
-    result ++ discoveredTests
+    discoveredTests
   }
 
   /*

src/plugin/src/sbt-test/interop/reports-missing-runtime/build.sbt

@@ -29,7 +29,7 @@ libraryDependencies ++= Seq(
 TaskKey[Unit]("checkDefinedTestsThrowsException") := {
   (Test / definedTests).result.value match {
     case Inc(cause:Incomplete) =>
-      val actualMessage = cause.directCause.map(c => c.getMessage).getOrElse("")
+      val actualMessage = cause.causes.headOption.flatMap(_.directCause).map(_.getMessage).getOrElse("")
       val expectedMessage = "Found at least one JUnit 5 test"
       assert(actualMessage.startsWith(expectedMessage),
         s"Expected an exception containing a message starting with `$expectedMessage` (actual: `$actualMessage`)")