Fix stack overflow in typedPipeMonoid.zero

twitter · May 22, 2017 · 2ca5089 · 2ca5089
1 parent 808ecb2
commit 2ca5089
Show file tree

Hide file tree

Showing 3 changed files with 11 additions and 1 deletion.
diff --git a/.DS_Store b/.DS_Store
diff --git a/scalding-core/src/main/scala/com/twitter/scalding/typed/TypedPipe.scala b/scalding-core/src/main/scala/com/twitter/scalding/typed/TypedPipe.scala
@@ -119,7 +119,7 @@ object TypedPipe extends Serializable {
    * TypedPipe instances are monoids. They are isomorphic to multisets.
    */
   implicit def typedPipeMonoid[T]: Monoid[TypedPipe[T]] = new Monoid[TypedPipe[T]] {
-    def zero = empty
+    def zero = TypedPipe.empty
     def plus(left: TypedPipe[T], right: TypedPipe[T]): TypedPipe[T] =
       left ++ right
   }

diff --git a/scalding-core/src/test/scala/com/twitter/scalding/TypedPipeTest.scala b/scalding-core/src/test/scala/com/twitter/scalding/TypedPipeTest.scala
@@ -17,6 +17,7 @@ package com.twitter.scalding
 
 import org.scalatest.{ FunSuite, Matchers, WordSpec }
 
+import com.twitter.algebird.Monoid
 import com.twitter.scalding.source.TypedText
 // Use the scalacheck generators
 import org.scalacheck.Gen
@@ -121,6 +122,15 @@ class TypedSumByKeyTest extends WordSpec with Matchers {
   }
 }
 
+class TypedPipeMonoidTest extends WordSpec with Matchers {
+  "typedPipeMonoid.zero" should {
+    "be equal to typedPipeMonoid.empty" in {
+      val mon = implicitly[Monoid[TypedPipe[Int]]]
+      assert(mon.zero == mon.empty)
+    }
+  }
+}
+
 class TypedPipeSortByJob(args: Args) extends Job(args) {
   TypedPipe.from(TypedText.tsv[(Int, Float, String)]("input"))
     .groupBy(_._1)