scala3: re-add SpecWiring for Scala 3

distage/distage-testkit-scalatest/src/main/scala-3/izumi/distage/testkit/scalatest/SpecWiring.scala

@@ -0,0 +1,28 @@
+package izumi.distage.testkit.scalatest
+
+import izumi.distage.framework.{CheckableApp, PlanCheckConfig, PlanCheckMaterializer}
+import izumi.distage.modules.DefaultModule
+
+abstract class SpecWiring[AppMain <: CheckableApp, Cfg <: PlanCheckConfig.Any](
+  val app: AppMain,
+  val cfg: Cfg = PlanCheckConfig.empty,
+  val checkAgainAtRuntime: Boolean = true,
+)(implicit
+  val planCheck: PlanCheckMaterializer[AppMain, Cfg],
+  defaultModule: DefaultModule[app.AppEffectType],
+) extends Spec1[app.AppEffectType]()(app.tagK, defaultModule)
+  with WiringAssertions {
+
+  s"Wiring check for `${planCheck.app.getClass.getCanonicalName}`" should {
+    "Pass at compile-time" in {
+      assert(planCheck.checkPassed)
+    }
+
+    if (checkAgainAtRuntime) {
+      "Pass at runtime" in {
+        planCheck.checkAgainAtRuntime().throwOnError()
+      }
+    }
+  }
+
+}