1 files changed, 75 insertions, 0 deletions
diff --git a/src/test/scala/firrtlTests/options/OptionsViewSpec.scala b/src/test/scala/firrtlTests/options/OptionsViewSpec.scala
new file mode 100644
index 00000000..dec6a99f
--- /dev/null
+++ b/src/test/scala/firrtlTests/options/OptionsViewSpec.scala
@@ -0,0 +1,75 @@
+// See LICENSE for license details
+
+package firrtlTests.options
+
+import org.scalatest.{FlatSpec, Matchers}
+
+import firrtl.options.OptionsView
+import firrtl.AnnotationSeq
+import firrtl.annotations.{Annotation,NoTargetAnnotation}
+
+class OptionsViewSpec extends FlatSpec with Matchers {
+
+  /* Annotations */
+  case class NameAnnotation(name: String) extends NoTargetAnnotation
+  case class ValueAnnotation(value: Int) extends NoTargetAnnotation
+
+  /* The type we want to view the annotations as */
+  case class Foo(name: Option[String] = None, value: Option[Int] = None)
+  case class Bar(name: String = "bar")
+
+  /* An OptionsView that converts an AnnotationSeq to Option[Foo] */
+  implicit object FooView extends OptionsView[Foo] {
+    private def append(foo: Foo, anno: Annotation): Foo = anno match {
+      case NameAnnotation(n)  => foo.copy(name  = Some(n))
+      case ValueAnnotation(v) => foo.copy(value = Some(v))
+      case _                  => foo
+    }
+
+    def view(options: AnnotationSeq): Option[Foo] = {
+      val annoSeq = options.foldLeft(Foo())(append)
+      Some(annoSeq)
+    }
+  }
+
+  /* An OptionsView that converts an AnnotationSeq to Option[Bar] */
+  implicit object BarView extends OptionsView[Bar] {
+    private def append(bar: Bar, anno: Annotation): Bar = anno match {
+      case NameAnnotation(n) => bar.copy(name = n)
+      case _                 => bar
+    }
+
+    def view(options: AnnotationSeq): Option[Bar] = {
+      val annoSeq = options.foldLeft(Bar())(append)
+      Some(annoSeq)
+    }
+  }
+
+  behavior of "OptionsView"
+
+  it should "convert annotations to one of two types" in {
+    /* Some default annotations */
+    val annos = Seq(NameAnnotation("foo"), ValueAnnotation(42))
+
+    info("Foo conversion okay")
+    FooView.view(annos) should be (Some(Foo(Some("foo"), Some(42))))
+
+    info("Bar conversion okay")
+    BarView.view(annos) should be (Some(Bar("foo")))
+  }
+
+  behavior of "Viewer"
+
+  it should "implicitly view annotations as the specified type" in {
+    import firrtl.options.Viewer._
+
+    /* Some empty annotations */
+    val annos = Seq[Annotation]()
+
+    info("Foo view okay")
+    view[Foo](annos) should be (Some(Foo(None, None)))
+
+    info("Bar view okay")
+    view[Bar](annos) should be (Some(Bar()))
+  }
+}