Merge pull request #255 from Atry/pr

Add the Using.defer method
ThoughtWorksInc · Jun 4, 2019 · 07ec26b · 07ec26b
2 parents 90969cf + a75e4fe
commit 07ec26b
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Showing 2 changed files with 52 additions and 2 deletions.
diff --git a/keywords-Using/build.sbt b/keywords-Using/build.sbt
@@ -1,5 +1,15 @@
 libraryDependencies += "org.scalatest" %%% "scalatest" % "3.0.6-SNAP2" % Test
 
+enablePlugins(Example)
+
+import meta._
+exampleSuperTypes := exampleSuperTypes.value.map {
+  case ctor"_root_.org.scalatest.FreeSpec" =>
+    ctor"_root_.org.scalatest.AsyncFreeSpec"
+  case otherTrait =>
+    otherTrait
+}
+
 scalacOptions ++= {
   import Ordering.Implicits._
   if (VersionNumber(scalaVersion.value).numbers < Seq(2L, 12L)) {
@@ -9,3 +19,5 @@ scalacOptions ++= {
     None
   }
 }
+
+libraryDependencies += "com.thoughtworks.dsl" %%% "keywords-await" % "1.3.0" % Test
diff --git a/keywords-Using/src/main/scala/com/thoughtworks/dsl/keywords/Using.scala b/keywords-Using/src/main/scala/com/thoughtworks/dsl/keywords/Using.scala
@@ -1,12 +1,12 @@
-package com.thoughtworks.dsl.keywords
+package com.thoughtworks.dsl
+package keywords
 
 import com.thoughtworks.dsl.Dsl
 import com.thoughtworks.dsl.Dsl.{!!, Keyword}
 import com.thoughtworks.dsl.keywords.Catch.{CatchDsl, DslCatch}
 
 import scala.concurrent.{ExecutionContext, Future}
 import scala.language.implicitConversions
-import scala.util.{Failure, Success, Try}
 import scala.util.control.NonFatal
 
 /** This [[Using]] keyword automatically manage resources in [[scala.concurrent.Future]], [[domains.task.Task]],
@@ -21,6 +21,44 @@ object Using {
 
   implicit def implicitUsing[R <: AutoCloseable](r: => R): Using[R] = Using[R](r _)
 
+  trait ScopeExitHandler extends AutoCloseable
+
+  /** Returns a [[Using]] keyword to execute a [[ScopeExitHandler]] when exiting the nearest enclosing scope
+    * that is annotated as [[Dsl.reset @reset]],
+    * (or the nearest enclosing function if [[compilerplugins.ResetEverywhere]] is enabled).
+    *
+    * @note This method is similar to [[apply]],
+    *       except the parameter type is changed from a generic `R` to the SAM type [[ScopeExitHandler]],
+    *       which allows for function literal expressions
+    *       in Scala 2.12+ or Scala 2.11 with `-Xexperimental` compiler option.
+    *
+    * @example The following function will perform `n *= 2` after `n += 20`:
+    *
+    *          {{{
+    *          import scala.concurrent.Future
+    *          import com.thoughtworks.dsl.keywords.Using.scopeExit
+    *          var n = 1
+    *          def multiplicationAfterAddition = Future {
+    *            !scopeExit { () =>
+    *              n *= 2
+    *            }
+    *            n += 20
+    *          }
+    *          }}}
+    *
+    *          Therefore, the final value of `n` should be `(1 + 20) * 2 = 42`.
+    *
+    *          {{{
+    *          import com.thoughtworks.dsl.Dsl.reset
+    *          Future {
+    *            !Await(multiplicationAfterAddition)
+    *            n should be(42)
+    *          }: @reset
+    *          }}}
+    *
+    */
+  def scopeExit(r: => ScopeExitHandler) = new Using(r _)
+
   def apply[R <: AutoCloseable](r: => R)(
       implicit dummyImplicit: DummyImplicit = DummyImplicit.dummyImplicit): Using[R] = new Using(r _)