Basic scalacheck properties for ByteString

akka-actor-tests/src/test/scala/akka/util/ByteStringSpec.scala

@@ -0,0 +1,38 @@
+package akka.util
+
+import org.scalatest.WordSpec
+import org.scalatest.matchers.MustMatchers
+import org.scalatest.BeforeAndAfterAll
+import org.scalatest.prop.Checkers
+import org.scalacheck._
+import org.scalacheck.Arbitrary._
+import org.scalacheck.Prop._
+import org.scalacheck.Gen._
+
+class ByteStringSpec extends WordSpec with MustMatchers with Checkers {
+
+  def genSimpleByteString(min: Int, max: Int) = for {
+    n ← choose(min, max)
+    b ← Gen.containerOfN[Array, Byte](n, arbitrary[Byte])
+  } yield ByteString(b)
+
+  implicit val arbitraryByteString: Arbitrary[ByteString] = Arbitrary {
+    Gen.sized { s ⇒
+      for {
+        chunks ← choose(0, s)
+        bytes ← listOfN(chunks, genSimpleByteString(1, s / (chunks max 1)))
+      } yield (ByteString.empty /: bytes)(_ ++ _)
+    }
+  }
+
+  "A ByteString" must {
+    "have correct size" when {
+      "concatenating" in { check((a: ByteString, b: ByteString) ⇒ (a ++ b).size == a.size + b.size) }
+      "dropping" in { check((a: ByteString, b: ByteString) ⇒ (a ++ b).drop(b.size).size == a.size) }
+    }
+    "be sequential" when {
+      "taking" in { check((a: ByteString, b: ByteString) ⇒ (a ++ b).take(a.size) == a) }
+      "dropping" in { check((a: ByteString, b: ByteString) ⇒ (a ++ b).drop(a.size) == b) }
+    }
+  }
+}