Add valueOr to Validated, analog to Xor.valueOr

typelevel · Jun 14, 2016 · 5765281 · 5765281
1 parent b149835
commit 5765281
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diff --git a/core/src/main/scala/cats/data/Validated.scala b/core/src/main/scala/cats/data/Validated.scala
@@ -27,6 +27,11 @@ sealed abstract class Validated[+E, +A] extends Product with Serializable {
    */
   def getOrElse[B >: A](default: => B): B = fold(_ => default, identity)
 
+  /**
+    * Return the Valid value, or the result of f if Invalid
+    */
+  def valueOr[B >: A](f: E => B): B = fold(f, identity)
+
   /**
    * Is this Valid and matching the given predicate
    */

diff --git a/tests/src/test/scala/cats/tests/ValidatedTests.scala b/tests/src/test/scala/cats/tests/ValidatedTests.scala
@@ -114,6 +114,12 @@ class ValidatedTests extends CatsSuite {
     }
   }
 
+  test("valueOr consistent with swap then map then merge") {
+    forAll { (v: Validated[String, Int], f: Int => String) =>
+      v.valueOr(f) should === (v.swap.map(f).merge)
+    }
+  }
+
   test("toEither then fromEither is identity") {
     forAll { (v: Validated[String, Int]) =>
       Validated.fromEither(v.toEither) should === (v)